Molecule Sentence Examples
He studied the DNA molecule to see if the child was related to the man.
The symbols of compounds become very concise, as the number of atoms of one kind in a molecule can be expressed by a sub-index.
By the entrance of amino or hydroxyl groups into the molecule dyestuffs are formed.
Additional evidence as to the structure of the molecule was discussed by Avogadro in 1811, and by Ampere in 1814.
A specific region of the DNA molecule, called a cistron, unwinds.Advertisement
A molecule of water (H20) consists of two atoms of hydrogen and one atoms of hydrogen and one atom of oxygen.
Each chromosome is really a very long DNA molecule.
A factor of considerable importance in determining boiling-points of isomers is the symmetry of the molecule.
The temporary dipoles are greatest for the longest molecule.
Usually, when the symbols of the elements are written or printed with a figure to the right, it is understood that this indicates a molecule of the element, the symbol alone representing an atom.Advertisement
While certain additive relations hold between some homologous series, yet differences occur which must be referred to the constitution of the molecule.
The introduction of negative groups into a molecule alters the boiling-point according to the number of negative groups already present.
Ferromagnetism was explained by Ampere on the hypothesis that the magnetization of the molecule is due to an electric current constantly circulating within it.
As a consequence of the structure of the molecule, which is an aggregation of atoms, the planes of the orbits around the latter may be oriented in various positions, and the direction of revolution may be right-handed or left-handed with respect to the direction of any applied magnetic field.
His view as to the dual composition of the toxin molecule has already been mentioned, and it is evident that if the haptophorous or combining group has its affinity satisfied by union with antitoxin, the toxin will no longer combine with living cells, and will thus be rendered harmless.Advertisement
Canine is a secondary base, forming a nitroso derivative with nitrous acid, a urethane with chlorcarbonic ester and a tertiary base (methyl conine) with methyl iodide; reactions which point to the presence of the = NH group in the molecule.
All these reactions take place concurrently, so that one molecule of a diglyceride may still retain its ephemeral existence, whilst another molecule is already broken up completely into free fatty acids and glycerin.
Don't forget to write the words " induced dipole " next to the bromine molecule.
Bulky substituents slow this process, however, and in the case of the molecule shown the two enantiomers have been isolated.
Since that date it has more than once been suggested that the molecular currents producing magnetism might be due to the revolution of one or more of the charged atoms or " ions " constituting the molecule.Advertisement
Living protoplasm, or in other words a biogen molecule, is regarded as consisting of a central atom group (Leistungskern), related to which are numerous secondary atom groups or sidechains, with unsatisfied chemical affinities.
The' side-chains constitute the means by which other molecules are added to the living molecule, e.g.
Silver fluoride, AgF, is obtained as quadratic octahedra, with one molecule of water, by dissolving the oxide or carbonate in hydrofluoric acid.
The band spectrum, which corresponds to the compound or at least to the molecule of titanium, certainly belongs to a lower temperature than the line spectrum of the same metal.
Kris studied the DNA molecule, now certain the woman's appearance spelled certain danger for him.Advertisement
An optional add-on 3D molecule viewer is available for Windows users - see below.
Still another view, advocated by Bordet, is that the union of toxin and antitoxin is rather of physical than of strictly chemical nature, and represents an interaction of colloidal substances, a sort of molecular deposition by which the smaller toxin molecule becomes entangled in the larger molecule of antitoxin.
This special carrier of energy is the molecule adenosine triphosphate, or ATP.
Removal by reacting with ammonia The most likely basic substance which a hydrogen ion is going to collide with is an ammonia molecule.
Ionization The process by which a neutral atom or molecule acquires or loses an electric charge.
The User should make a list of the names of all the polar atoms in the Probe Molecule.
Each chromosome is really a very long molecule of DNA wound up and coiled around special proteins to form chromatin.
Its molecule contains an extended system of delocalised electrons called a chromophore.
Difference electron density for a molecule of AMPPNP is observed in the kinase active site cleft.
When a solution of the sample molecule is mixed with a metal colloid the molecules are absorbed onto the surface of the colloids.
These peptides probably alter the conformation of the phosphodiester chain through a complex interaction with DNA molecule.
This fragment of the complete ACTH molecule does not stimulate the adrenal cortex to produce hormones.
John Warren will provide additional scientific support for small molecule crystallography.
I also advise the small molecule crystallography service in the Chemistry Department.
The cyanide ion comes from hydrogen cyanide ion comes from hydrogen cyanide, which is a covalent molecule.
Because the valence electrons in the water molecule spend more time around the oxygen.. .
Using fluorescence excitation, sensitivities down to the single molecule detection limit can be achieved.
If a molecule which absorbs UV radiation does not fluoresce it means that it must have lost its energy some other way.
Some proteins fluoresce naturally, because the fluoresce naturally, because the fluorescent molecule is actually a part of the protein.
By using a laser which excites the OH and induces fluorescence, he is able to measure the concentrations of the molecule.
The human mitochondrial genome is a small circular DNA molecule 16 568 bp in length containing 37 genes.
A normal hemoglobin molecule contains two alpha globin molecule contains two alpha globins and two beta globins to make up the complement of 4 globins.
The molecule consists of a short triple helix about 105 nm in length with a large globular domain at each end.
This team is investigating the ' signal molecule ' which produces the scarring around the brain thought to be responsible for causing hydrocephalus.
An ammonia molecule removes a hydrogen ion from the -NH 3 + group in a reversible reaction.
This hydrophobic Probe (which we will call HP) represents a hydrophobic molecule approaching the surface of the Target.
Prions are rather ill-defined infectious agents believed to consist of a single type of protein molecule with no nucleic acid component.
Like H 2 O, CO 2 is a chemically inert molecule.
Draw the structure of the phospholipid molecule phosphatidyl inositol.
In AS and A2 Chemistry, we only need to know about geometrical isomerism caused by a C=C bond in the molecule.
Each antibody molecule has either lambda or kappa light chains, not both.
Luciferase This molecule is an enzyme which reacts with ATP to cleave luciferin, its substrate.
When imaging macromolecules, a large region, about 100 square nanometers, of the AFM tip makes contact with the molecule.
That means that if you rotate the molecule, the text will also rotate.
In order for a cell to use calcium as a signaling molecule, the cell must create calcium gradients across membranes.
There is thus a pressing need for a reliable means of identifying the hand of a chiral molecule.
A polymer is a long molecule made up of lots of repeating units called monomers.
The molecule prevents Plasmodium, the malaria mosquito, from moving from the mosquito's gut to its salivary glands.
Most odors are composed of multiple odorant molecules, and each odorant molecule activates several odorant receptors.
The retinol is oxidized to its aldehyde, retinal, which complexes with a molecule in the eye called opsin.
A nitrogen molecule is thus a good approximation to a harmonic oscillator.
The camphor molecule has one polar atom (a carbonyl oxygen) and three methyl groups.
This leaves the cycle, and two of these triose phosphate molecules combine to form one glucose molecule using the glycolysis enzymes in reverse.
The molecule prevents plasmodium, the malaria mosquito, from moving from the mosquito's gut to its salivary glands.
However, few organic compounds react readily with water... Their molecules are mostly much less polar than the very polar water molecule.
The exterior of the molecule is mainly polar, whereas the interior is mainly non-polar.
You again get a polar molecule, although with a reversed polarity from the first example.
In the molecule above, the two peptides have joined together to form a dipeptide; many peptides join together to form a polypeptide.
In fact glucose is not a suitable molecule for demonstrating the use of the hydrophobic probe in conjunction with Program Group.
This could be an activated water molecule as seen in aspartic proteinases or an amino acid side chain.
In aspartic peptidases, the water molecule is directly bound by the side chains of aspartic residues.
In the present case index I will refer to our particular cationic nitrogen in our particular lysine residue in our particular protein Target molecule.
These groups were also used to maintain the high water solubility of the resulting CD molecule.
Not even a molecule of oxygen is required for this process, and thus the 50m sprint is a nice ' anaerobic ' test.
To fuse the template with an existing substructure (of the same molecule type) move it toward the substructure.
The crystal symmetry will be used to generate atom positions from a unique molecule.
Suppose a water molecule is going to react with the carbon tetrachloride.
They also theorize that if the strands are separated then each can form the template for the synthesis of an identical DNA molecule.
Oxford BioMedica has also agreed to develop screens for small molecule therapeutics for RPR.
Sometimes it is possible for the amino group of an amino acid to be transferred to another molecule by a process called transamination.
It is evident that these laws all follow from the idea that a compound molecule can only alter through the addition or subtraction of one or more complete atoms, together with the idea that all the molecules in a pure substance are alike.
To take the simplest possible case, if Dalton had been correct in assuming that the molecule of water was made up of one atom of oxygen and one of hydrogen, then the experimental fact that water contains eight parts by weight of oxygen to one part of hydrogen, would at once show that the atom of oxygen is eight times as heavy as the atom of hydrogen, or that, taking the atomic weight of hydrogen as the unit, the.
Thus the symbol or formula H 2 O for water expresses the view that the molecule of water consists of one atom of oxygen and two of hydrogen; and if we know the atomic weights of oxygen and hydrogen, it also tells us the composition of water by weight.
Its ratio of specific heats has very nearly the ideal value 1 666, appropriate to a monatomic molecule.
From the condensation of two molecules of ethyl borate with one molecule of zinc ethyl the compound B2 C2H5.
If, on the other hand, we have to deal with a system of molecules of whose motions in the aggregate we become conscious only by indirect means, while we know absolutely nothing either of the motions or positions of any individual molecule, it is obvious that we cannot grasp single molecules and control their movements so as to derive the full amount of work from the system.
Dewar led him to see the true dynamical explanation of the Crookes radiometer in the largeness of the free path of the molecule of the highly rarefied air.
The evolution of the notion of elements is treated under Element; the molecular hypothesis of matter under Molecule; and the genesis of, and deductions from, the atomic theory of Dalton receive detailed analysis in the article Atom.
Simultaneously with this discussion of the atom and molecule, great controversy was ranging over the constitution of com pounds, more particularly over the carbon or organic compounds.
They assumed the atom to be the smallest part of matter which can exist in combination, and the molecule to be the smallest part which can enter into a chemical reaction.
In 1860 there prevailed such a confusion of hypotheses as to the atom and molecule that a conference was held at Karlsruhe to discuss the situation.
The development of the atomic theory and its concomitants - the laws of chemical combination and the notion of atoms and equivalents - at the hands of Dalton and Berzelius, the extension to the modern theory of the atom and molecule, and to atomic and molecular weights by Avogadro, Ampere, Dumas, Laurent, Gerhardt, Cannizzaro and others, have been noted.
The structure of the molecule, which mainly followed investigations in organic compounds, Frankland's conception of valency, and finally the periodic law, have alsobeen shown in their chronological order.
The recognition of the polybasicity of acids, which followed from the researches of Thomas Graham and Liebig, had caused Williamson to suggest that dibasic acids could be referred to a double water type, the acid radical replacing an atom of hydrogen in each water molecule; while his discovery of tribasic formic ether, CH(OC 2 H 5) 3, in 1854 suggested a triple water type.
A more accurate expression (see Condensation Of Gases and Molecule) is (p+a/v 2) (v - b) =RT, in which a and b are quantities which depend on the composition of the gas, and vary from one gas to another.
In the article Condensation Of Gases (see also Molecule) it is shown that the characteristic equation of gases and liquids is conveniently expressed in the form (p+a/v 2) (v - b) = RT.
By considerations based on the kinetic theory of gases (see Molecule) it may be shown that when no energy is utilized in separating the atoms of a molecule, this ratio is 5/3= 1.67.
If twelve grammes of amorphous carbon be burnt to carbon dioxide under constant volume, the heat evolved (96.96 cal.) does not measure the entire thermal effect, but the difference between this and the heat required to break down the carbon molecule into atoms. If the number of atoms in the carbon molecule be denoted by n, and the heat required to split off each atom from the molecule by d, then the total heat required to break down a carbon molecule completely into atoms is nd.
The results obtained for the (1.2) and (1.4) chlorbenzoic acids also illustrate the dependence of crystal form and structure on the orientation of the molecule.
It may be generally concluded that the substitution of alkyl, nitro, hydroxyl, and haloid groups for hydrogen in a molecule occasions a deformation of crystal structure in one definite direction, hence permitting inferences as to the configuration of the atoms composing the crystal; while the nature and degree of the alteration depends (1) upon the crystal structure of the unsubstituted compound; (2) on the nature of the substituting radicle; (3) on the complexity of the substituted molecule; and (4) on the orientation of the substitution derivative.
Pure d-glucose, which may be obtained synthetically (see Sugar) or by adding crystallized cane sugar to a mixture of 80% alcohol and 115 volume of fuming hydrochloric acid so long as it dissolves on shaking, crystallizes from water or alcohol at ordinary temperatures in nodular masses, composed of minute six-sided plates, and containing one molecule of water of crystallization.
If from some cause the cell be damaged in such a way as to produce disintegration of the cytoplasm, there will be a breaking down of that combination, so that the fat will be set free from the complex protein molecule in which it was combined as a soap-albumin, and will become demonstrable by the usual methods as small droplets of oil.
The isomerism of crotonic and isocrotonic acids is to be explained on the assumption of a different spatial arrangement of the atoms in the molecule (see Stereochemistry).
Absence of rotary power when asymmetric carbon atoms are present, may be caused by an internal compensation within the molecule as with the inactive tartaric acid (mesotartaric acid), or may be due to the fact that the compound is an equimolecular mixture of leftand right-hand varieties, this being the case with racemic acid that was broken by Louis Pasteur into laevoand dextro-tartaric acid (see Stereo-Isomerism).
Ladenburg (1883, 1887) demonstrated that the molecule contained a reduced pyridine nucleus.
The real C 2 molecule is however a singlet ground state, i.e..
In Henry 's Law the solute molecule is surrounded by solvent molecules at the limit.
If a solvent molecule in the vapor hits a bit of surface occupied by the solute particles, it may well stick.
Infrared spectra of the molecule CH 4 - one of at least ten new molecules detected by ISO.
The InChI does not define the stereochemistry of the molecule.
Squalene is a naturally occurring molecule absorbed from food, and synthesized as a precursor for cholesterol, myelin, and steroid hormones.
Here 's another example... The chloromethane molecule, CH 3 Cl molecule is tetrahedral in shape.
Consider the vibrations of a triatomic molecule, e.g. CO 2, in detail.
The researchers believe the trilobite molecule can be created by manipulating a rubidium BEC with laser pulses or external electromagnetic fields.
CrystalMaker provides stunning visualization of novel tweezer molecule, used in sequence analysis.
In effect molecule to man evolution is a belief in the logical absurdity of undirected progress.
But each molecule of water vapor in the atmosphere, containing two atoms of hydrogen, assures an adequate supply.
A free radical is an unstable molecule with a missing electron.
Each pore is smaller than a droplet of water, but larger than a vapor moisture molecule.
According to Gore-tex.com, the pores are roughly 20,000 times smaller than a molecule of water and 700 times larger than the molecules of moisture vapor.
For some unknown reason, a protein molecule is unable to correctly bond with another protein molecule.
The result is a protein molecule that is insoluble protein -like a form of plaque.
Cancer results from alterations (mutations) in genes that make up DNA, the master molecule of the cell.
This test measures the speed at which a molecule moves in a gel and can detect abnormal hemoglobin HbS.
Mucopolysaccharide-A complex molecule made of smaller sugar molecules strung together to form a chain.
Chelation-The process by which a molecule encircles and binds to a metal and removes it from tissue.
Also describes a chemical reaction in which one or more electrons are added to an atom or molecule.
The porphyrias are disorders in which the body produces too much porphyrin and insufficient heme (an iron-containing nonprotein portion of the hemoglobin molecule).
Biosynthesis of heme is a multistep process that begins with simple molecules and ends with a large, complex heme molecule.
As a heme precursor molecule moves through each step, an enzyme modifies the precursor in some way.
If a precursor molecule is not modified, it cannot proceed to the next step, causing a buildup of that specific precursor.
The heme molecule is composed of porphyrin and an iron atom.
Much of the heme biosynthesis pathway is dedicated to constructing the porphyrin molecule.
This light causes changes in how the bilirubin molecule is shaped, which makes it easier to excrete.
This theory explains the fluorescence of anthranilic acid (o-aminobenzoic acid), by regarding the aniline residue as the luminophore, and the carboxyl group as the fluorogen, since, apparently, the introduction of the latter into the non-fluorescent aniline molecule involves the production of a fluorescent substance.
Isomorphism may be defined as the existence of two or more different substances in the same crystal form and structure, polymorphism as the existence of the same substance in two or more crystal modifications, and morphotropy (after P. von Groth) as the change in crystal form due to alterations in the molecule of closely (chemically) related substances.
The measure of the loss of symmetry associated with the introduction of alkyl groups depends upon the relative magnitudes of the substituent group and the rest of the molecule; and the larger the molecule, the less would be the morphotropic effect of any particular substituent.
The nitro group behaves very similarly to the hydroxyl group. The effect of varying the position of the nitro group in the molecule is well marked, and conclusions may be drawn as to the orientation of the groups from a knowledge of the crystal form; a change in the symmetry of the chemical molecule being often attended by a loss in the symmetry of the crystal.
Thus, if the molecule of a substance in solution is represented by AB, Grotthus considered a chain of AB molecules to exist from one electrode to the other.
Under the influence of an applied electric force, he imagined that the B part of the first molecule was liberated at the anode, and that the A part thus isolated united with the B part of the second molecule, which, in its turn, passed on its A to the B of the third molecule.
As we have seen, Grotthus imagined that it was the electric forces which sheared the ions past each other and loosened the chemical bonds holding the opposite parts of each dissolved molecule together.
The electrical phenomena show that there are two ions to the molecule, and that these ions are electrically charged.
Corresponding with this result we find that the freezing point of dilute solutions indicates that two pressure-producing particles per molecule are present.
In other cases, such as that of litmus, both the ion and the undissociated molecule are coloured, but in different ways.
When the solutions may be taken as effectively dilute, so that the gas laws apply to the osmotic pressure, this relation reduces to E _ nrRT to c1 ey gE c2 where n is the number of ions given by one molecule of the salt, r the transport ratio of the anion, R the gas constant, T the absolute temperature, y the total valency of the anions obtained from one molecule, and c i and c 2 the concentrations of the two solutions.
If ozone is passed into a solution of rubber in chloroform the caoutchouc combines with a molecule of ozone forming a compound of the empirical composition C 5 H 8 O 8.
This result he considered to be due, not to any removal of impurities, but to an actual splitting-up of the yttrium molecule into its constituents, and he ventured to draw the provisional conclusion that the so-called simple bodies are in reality compound molecules, at the same time suggesting that all the elements have been produced by a process of evolution from one primordial stuff or "protyle."
Since the molecule contains an asymmetric carbon atom, the acid exists in three forms, one being an inactive "racemic" mixture, and the other two being optically active forms. The inactive variety is known as paramandelic acid.
The acid salts are obtained by the addition of one molecule of alkali to two molecules of the acid in concentrated alcoholic solution at a low temperature.
The oldest and perhaps most reasonable idea represents guncotton as cellulose trinitrate, but this has been much disputed, and various formulae, some based on cellulose as C, 2 H200 10, others on a still more complex molecule, have been proposed.
Strong or weak solutions of these substances also decompose it, producing some alkali nitrate and nitrite, the cellulose molecule being only partially restored, some quantity undergoing oxidation.
Some glycerin may be re-formed, but with very strong alkaline solutions little of the glycerin molecule escapes destruction, oxalic acid and several other products resulting.
Fraser proved that by substitution of molecules in certain compounds a stimulant could be converted into a sedative action; thus by the addition of the methyl group CH 2 to the molecule of strychnine, thebaine or brucine, the tetanizing action of these drugs is converted into a paralysing action.
In addition trisaccharoses are known of the formula C13H32016; these on hydrolysis yield one molecule of a monosaccharose and one of a disaccharose, or three of a monosaccharose.
The plane projection of molecular structures which differ stereochemically is discussed under Stereoisomerism; in this place it suffices to say that, since the terminal groups of the hexaldose molecule are different and four asymmetric carbon atoms are present, sixteen hexaldoses are possible; and for the hexahydric alcohols which they yield on reduction, and the tetrahydric dicarboxylic acids which they give on oxidation, only ten forms are possible.
Employing the notation in which the molecule is represented vertically with the aldehyde group at the bottom, and calling a carbon atom+or - according as the hydrogen atom is to the left or right, the possible configurations are shown in the diagram.
The isomerism which occurs as soon as the molecule contains a few carbon atoms renders any classification based on empirical molecular formulae somewhat ineffective; on the other hand, a scheme based on molecular structure would involve more detail than it is here possible to give.
In the preceding instances the carboxyl group has been synthesized or introduced into a molecule; we have now to consider syntheses from substances already containing carboxyl groups.
Beside the ordinary acid and neutral salts, a series of salts called quadroxalates is known, these being salts containing one molecule of acid salt, in combination with one molecule of acid, one of the most common being "salt of sorrel," KHC 2 0 4.
Their experiments, although not conclusive, appear to indicate that the molecule of a metal when in dilute solution often consists of one atom.
In the cases of aluminium dissolved in tin and of mercury or bismuth in lead, it is at least probable that the molecules in solution are Al 2j Hg 2 and Bit respectively, while tin in lead appears to form a molecule of the type Sn4.
The value of the index, n, appears to be different for different types of molecule.
We may therefore reasonably assume that the limiting values of the specific heats at zero pressure do not vary with the temperature, provided that the molecule is stable and there is no dissociation.
If two monatomic molecules, having energy of translation only, equivalent to 3 degrees of freedom, combined to form a diatomic molecule with 5 degrees of freedom, the energy lost would.
If two diatomic molecules, having each 5 degrees of freedom, combine to form a molecule with 6 degrees of freedom, we should have n = 2, or the energy lost would be 2pc per unit mass.
They are continually changing partners, the ratio c/V representing approximately the ratio of the time during which any one molecule is paired to the time during which it is free.
In air of considerable density the mean free path of a molecule, between its collisions with other molecules, is exceedingly small, and any such increase of gaseous pressure in front of the black surface would be immediately neutralized by flow of the gas from places of high to places of low pressure.
For instance, if oxygen and hydrogen combine to form water, we have no experimental evidence that the molecule of oxygen is not in the very same place with the two molecules of hydrogen.
The smallest unit of matter with which physical phenomena are concerned is the molecule.
When chemical phenomena occur the molecule may be divided into atoms, and these atoms, in the presence of electrical phenomena, may themselves be further divided into electrons or corpuscles.
At a certain temperature a stage will be reached in which it is a frequent occurrence for a molecule to wander so far from its position of equilibrium, that it does not return but falls into a new position of equilibrium and oscillates about this.
A molecule escaping from its original position in a body will usually fall into a new position in which it will be held in equilibrium by the forces from a new set of neighbouring molecules.
But if the wandering molecule was originally close to the surface of the body, and if it also happens to start off in the right direction, it may escape from the body altogether and describe a free path in space until it is checked by meeting a second wandering molecule or other obstacle.
When a liquid undergoing evaporation is contained in a closed vessel, a molecule which has left the liquid will, after a certain 1 Other processes also help in the conduction of heat, especially in substances which are conductors of electricity.
A number of molecules moving in obedience to dynamical laws will pass through a series of configurations which can be theoretically determined as soon as the structure of each molecule and the initial position and velocity of every part of it are known.
Each impinging molecule exerts an impulsive pressure equal to mu on the boundary before the component of velocity of its centre of gravity normal to the boundary is reduced to zero.
The value of n is the number of terms in the energy of the molecule beyond that due to translation.
No molecule could possibly be imagined for which n had a negative value or the value n =1.
Pyrophosphoric acid, 'H' 4 P 2 0 7, is a tetrabasic acid which may be regarded as derived by eliminating a molecule of water between two molecules of ordinary phosphoric acid; its constitution may therefore be written (HO) 2 0P O PO(OH) 2.
Metaphosphoric acid, HP0 3, is a monobasic acid which may be regarded as derived from orthophosphoric acid by the abstraction of one molecule of water, thus H 3 PO 4 - H 2 O = HP0 3; its constitution is therefore (HO)P0 2.
Of the acid orthophosphates, the mono-calcium salt, CaH4(P04)2, may be obtained as crystalline scales, containing one molecule of water, by evaporating a solution of the normal salt in hydrochloric or nitric acid.
A characteristic property of the alkaline fluorides is their power of combining with a molecule of hydrofluoric acid and with the fluorides of the more electro-negative elements to form double fluorides, a behaviour not shown by other metallic halides.
Thus, if one molecule is disturbed from its mean position, it communicates the disturbance to its neighbours, and so a wave is propagated.
Chromium salts readily combine with ammonia to form complex salts in which the ammonia molecule is in direct combination with the chromium atom.
When the molecule is losing energy the intensity of each kind of radiation depends principally on the rapidity with which it can be renewed by molecular impacts.
Thus if a molecule were set into vibration at a specified time and oscillated according to the above equation during a finite period, it would not send out homogeneous vibrations.
If N be the frequency of a homogeneous vibration sent out by a molecule at rest, the apparent frequency will be N (1 v/ V), where V is the velocity of light and v is the velocity of the line of sight, taken as positive if the distance from the observer increases.
Compounds generally show spectra of resolvable bands, and if an elementary body shows a spectrum of the same type we are probably justified in assuming it to be due to a complex molecule.
But that it may be given by the ordinary diatomic molecule is exemplified by oxygen, which gives in thick layers by absorption one of the typical sets of bands which were used by Deslandres and others to investigate the laws of distribution of frequencies.
No conclusion can therefore be drawn, as Stark' has more recently pointed out, respecting the charge of the molecule which emits the observed spectrum.
Applying the reasoning to the case of a homogeneous radiation traversing an absorbing medium, we realize that the mutual disturbances of the molecules by collision or otherwise must bring in the free period of the molecule whatever the incident radiation may be.
It will be advantageous if the spectra of ammonia, benzene, aniline and dimethyl aniline be compared, when the re-' markable coincidences will at once become apparent, as also the different weighting of the molecule.
In order to explain the electrical properties of a solution, for instance of potassium chloride, we are driven to believe that each molecule of the salt is dissociated into two parts, potassium and chlorine, each associated with an electric charge equal in amount but opposite in sign.
The greater the number of water molecules attached to one sugar molecule, the less the residual volume, and the greater the theoretical pressure.
Boltzmann offered a demonstration of the law of osmotic pressure in dilute solutions, based on the idea that the mean energy of translation of a molecule should be the same in the liquid as in the gaseous state.
If each molecule of the solute combines with a certain number of molecules of the solvent in such a way as to render them inactive for evaporation, we get a lowering of vapour pressure.
Each molecular complex, formed by solution and solvent, is treated as a single molecule.
If there are n molecules of solute to N of solvent originally, and each molecule of solute combines with a molecule of solvent, we get for the ratio of vapour pressures p/p'=(N - an)/(N - an+n), while the relative lowering of vapour pressure is (p - p')/p=n/(N - an).
The same value had previously been found for mercury vapour by Kundt and Warburg, and had been regarded as confirmatory of the monatomic character attributed on chemical grounds to the mercury molecule.
On oxidation, the molecule is split at the carbonyl group and a mixture of acids is obtained.
In the latter reaction it is assumed that the isodiazohydroxide first formed is immediately attacked by a second molecule of the amine.
Traube, Ber., 1882, 15, p. 659); in the oxidation of zinc, lead and copper in presence of water, and in the electrolysis of sulphuric acid of such strength that it contains two molecules of water to one molecule of sulphuric acid (M.
This explains a good deal of the possible instability; and, from a practical point of view, it coincides with the fact that such a large amount of energy can be stored in our most intense explosives such as dynamite, the explanation being that hydrogen is attached to carbon distant from oxygen in the same molecule, and that only the characteristic resistance of the carbon linkage prevents the hydrogen from burning, which is the main occurrence in the explosion of dynamite.
This conception has rendered possible a clear idea of the linking or internal structure of the molecule, for example, in the most simple case, methane, CH 4, is expressed by H H-C-H H It is by this conception that possible and impossible compounds are at once fixed.
In this equation a relates to molecular attraction; and it is not improbable that in isomeric molecules, containing in sum the same amount of the same atoms, those mutual attractions are approximately the same, whereas the chief difference lies in the value of b, that is, the volume occupied by the molecule itself.
For what reason this volume may differ from case to case lies close at hand; in connexion with the notion of negative and positive atoms, like chlorine and hydrogen, experience tends to show that the former, as well as the latter, have a mutual repulsive power, but the former acts on the latter in the opposite sense; the necessary consequence is that, when those negative and positive groups are distributed in the molecule, its volume will be smaller than if the negative elements are heaped together.
Other physical properties might be considered; as a general rule they depend upon the distribution of negative and positive elements in the molecule.
The investigation also showed that the nature of the acid used affected the result, for in an homologous series of acids it was found that as the molecule of the acid became more complex, the rate of esterification became less.
Thomson's estimate of the mass, must be upwards of forty times that of the hydrogen molecule.
This, at first sight, paradoxical result is explained by the fact that the mean free path of each molecule increases in the same proportion as the density is diminished, so that as the number of molecules crossing each square centimetre decreases, the distance to which each carries its momentum increases, and the total transfer of momentum is unaffected by variation of density.
Schonbein (loc. cit.) assumed that the ordinary oxygen molecule is decomposed into two parts which carry electrical charges of opposite kinds, the one with the positive charge being called "antozone" and the other carrying the negative charge being called "ozone," one variety being preferentially used up by the oxidizing compound or element and the other for the secondary reaction.
Traube (loc. cit.), on the other hand, concludes that the oxygen molecule enters into action as a whole and that on the oxidation of metals, hydrogen peroxide and the oxide of the metal are the primary products of the reaction.
Only so much lime is used that an acid manganite is formed corresponding to one molecule of calcium oxide to two of manganous oxide.
They may be regarded as the anhydrides of the alcohols, being formed by elimination of one molecule of water from two molecules of the alcohols; those in which the two hydrocarbon radicals are similar are known as simple ethers, and those in which they are dissimilar as mixed ethers.
It separates from benzene and thiophene with one molecule of the "solvent of crystallization."
Thus The Direct Experimental Evidence Is Somewhat Meagre And Conflicting, But The Question Of The Relation Of The Specific Heats Of Gases Is One Of Great Interest In Connexion With The Kinetic Theory And The Constitution Of The Molecule.
For Diatomic Or Compound Gases Clerk Maxwell Supposed That The Molecule Would Also Possess Energy Of Rotation, And Endeavoured To Prove That In This Case The Energy Would Be Equally Divided Between The Six Degrees Of Freedom, Three Of Translation And Three Of Rotation, If The Molecule Were Regarded As A Rigid Body Incapable Of Vibration Energy.
Boltzmann Suggested That A Diatomic Molecule Regarded As A Rigid Dumb Bell Or Figure Of Rotation, Might Have Only Five Effective Degrees Of Freedom, Since The Energy Of Rotation About The Axis Of Symmetry Could Not Be Altered By Collisions Between The Molecules.
Since Much Smaller Values Are Found For More Complex Molecules, We May Suppose That, In These Cases, The Energy Of Rotation Of A Polyatomic Molecule May Be Greater Than Its Energy Of Translation, Or Else That Heat Is Expended In Splitting Up Molecular Aggregates, And Increasing Energy Of Vibration.
Two hydrated forms have been described, one containing three molecules of water and the other half a molecule.
It is assumed that each molecule of solute combines with a molecules of solvent according to the ordinary law of chemical combination, and that the number a, representing the degree of hydration, remains constant within wide limits of temperature and concentration.
The explanation of this relation is that each of the n compound molecules counts as a single molecule, and that, if all the molecules were solvent molecules, the vapour-pressure would be p', that of the pure solvent.
The highest pressures recorded for cane-sugar are nearly three times as great as those given by van't Hoff's formula for the gas-pressure, but agree very well with the vapour-pressure theory, as modified by Callendar, provided that we substitute for V in Arrhenius's formula the actual specific volume of the solvent in the solution, and if we also assume that each molecule of sugar in solution combines with 5 molecules of water, as required by the observations on the depression of the freezing-point and the rise of the boiling-point.
Whereas gluten is a complex protein found in grains, casein is the large protein molecule within cow's milk.
It is not actually gluten per se that is responsible for triggering the autoimmune response in celiacs, but, rather, specific proteins within the gluten molecule.
Scientists say that the gluten molecule can't penetrate the skin to get to the digestive system.
Gluten represents a large protein molecule that can be difficult to digest.
Cholesterol is a compound, actually a fatty molecule, that is both produced by our livers and found in some foods.
Collagen is a molecule that is part of normal skin.
Roughly 80% of the skin is made up of collagen, the molecule responsible for making the skin smooth, strong and firm.
It would be a serious business to draw a Daltonian diagram for such a molecule.
The decomposition of the complex molecule of the sugar liberates a certain amount of energy, as can be seen from the study of the fermentation set tig by yeast, which is a process of this kind, in that it is intensified by the absence of oxygen.
This salt, on standing, decomposes into barium dithionate, BaS206, and diethyl disulphide, (C2H5)2S2, which points to the presence of the SH group in the molecule.
The oxychloride, bromides, and other compounds were subsequently discovered; here we need only notice Moissan's preparation of the trifluoride and Thorpe's discovery of the pentafluoride, a compound of especial note, for it volatilizes unchanged, giving a vapour of normal density and so demonstrating the stability of a pentavalent phosphorus compound (the pentachloride and pentabromide dissociate into a molecule of the halogen element and phosphorus trichoride).
These bands are due to molecular oscillations; Hartley suggests the carbon atoms to be rotating and forming alternately single and double linkages, the formation of three double links giving three bands, and of three single links another three; Baly and Collie, on the other hand, suggest the making and breaking of links between adjacent atoms, pointing out that there are seven combinations of one, two and three pairs of carbon atoms in the benzene molecule.
Bamberger, on the other hand, extends his views on benzene and naphthalene and assumes the molecule to be (1).
We may therefore conclude that the molecular volume depends more upon the internal structure of the molecule than its empirical content.
Schroeder the silver salts of the fatty acids exhibit additive relations; an increase in the molecule of CH2 causes an increase in the molecular volume of about 15'3.
For a further discussion of the ratio of the specific heats see Molecule.
The thermal effect of the " alcohol " group C. OH may be determined by finding the heat of formation of the alcohol and subtracting the thermal effects of the remaining linkages in the molecule.
It is remarkable that the position of the halogen in the molecule has no effect on the heat of formation; for example, chlorpropylene and allylchloride, and also ethylene dichloride and ethylidene dichloride, have equal heats of formation.
Since a/d is the real specific volume of the molecule, it is therefore a constant; hence (N2-I)/(N2+2)d is also a constant and is independent of all changes of temperature, pressure, and of the state of aggregation.
The nitro group has a very important action mainly on account of the readiness with which it can be introduced into the molecule, but its effect is much less than that of the azo group. The colour produced is generally yellow, which, in accordance with a general rule, is intensified with an increase in the number of groups; compare, for example, mono-, diand tri-nitrobenzene.
The carbonyl group by itself does not produce colour, but when two adjacent groups occur in the molecule, as for example in the a-diketones (such as di-acetyl and benzil), a yellow colour is produced.
According to the modern theory of auxochromic action, the introduction of a group into the molecule is accompanied by some strain, and the alteration in colour produced is connected with the magnitude of the strain.
C. C. Baly regards colour as due to " isorropesis " or an oscillation between the residual affinities of adjacent atoms composing the molecule.
In this manner, the B part of the last molecule of the chain was seized by the A of the last molecule but one, and the A part of the last molecule liberated at the surface of the cathode.
Clausius extended to electrolysis the chemical ideas which looked on the opposite parts of the molecule as always changing partners independently of any electric force, and regarded the function of the current as merely directive.
Arrhenius pointed out that these exceptions would be brought into line if the ions of electrolytes were imagined to be separate entities each capable of producing its own pressure effects just as would an ordinary dissolved molecule.
Weber therefore supposed each molecule to be acted on by a force tending to preserve it in its original direction, the position actually assumed by the axis being in the direction of the resultant of this hypothetical force and the applied magnetizing force.
Maxwell (Electricity and Magnetism, § 444), recognizing that the theory in this form gave no account of residual magnetization, made the further assumption that if the deflection of the axis of the molecule exceeded a certain angle, the axis would not return to its original position when the deflecting force was removed, but would retain a permanent set.
The fact being established that magnetism is essentially a molecular phenomenon, the next step is to inquire what is the constitution of a magnetic molecule, and why it is that some molecules are ferromagnetic, others paramagnetic, and others again diamagnetic. The best known of the explanations that have been proposed depend upon the magnetic action of an electric current.
The creation of an external magnetic field H will, in accordance with Lenz's law, induce in the molecule an electric current so directed that the magnetization of the equivalent magnet is opposed to the direction of the field.
If the structure of the molecule is so perfectly symmetrical that, in the absence of any external field, the resultant magnetic moment of the circulating electrons is zero, then the application of a field, by accelerating the right-handed (negative) revolutions, and retarding those which are left-handed, will induce in the substance a resultant magnetization opposite in direction to the field itself; a body composed of such symmetrical molecules is therefore diamagnetic. If however the structure of the molecule is such that the electrons revolving around its atoms do not exactly cancel one another's effects, the molecule constitutes a little magnet, which under the influence of an external field will tend to set itself with its axis parallel to the field.
As the carbon content of the molecule increases, they become less soluble in water, and their smell becomes less marked with the increase in boiling point, the highest members of the series being odourless solids, which can only be distilled without decomposition invacuo.
Substitution takes place usually in the nucleus and only rarely in the side chain, and according to the conditions of the experiment and the nature of the compound acted upon, one or more nitro groups enter the molecule.
The nitro group in the aromatic series is bound very firmly in the molecule and is not readily exchanged for other groups.
Fischer has proposed formulae for the important disaccharoses, and in conjunction with Armstrong devised a method for determining how the molecule was built up, by forming the osone of the sugar and hydrolysing, whereupon the hexosone obtained indicates the aldose part of the molecule.
The next higher members of the series are liquids of low boiling point also readily soluble in water, the solubility and volatility, however, decreasing with the increasing carbon content of the molecule, until the highest members of the series are odourless solids of high boiling point and are insoluble in water.
If the nitrogen atom in the quaternary ammonium salts be in combination with four different groups, then the molecule is asymmetrical, and the salt can be resolved into optically active enantiamorphous isomerides.
Again, anode reactions, such as are observed in the electrolysis of the fatty acids, may be utilized, as, for example, when the radical CH3C02 - deposited at the anode in the electrolysis of acetic acid - is dissociated, two of the groups react to give one molecule of ethane, C 2 H 6, and two of carbon dioxide.
This view, which was specially supported by Gay-Lussac and Leopold Gmelin and accepted by Berzelius, necessitated that all acids were monobasic. The untenability of this theory was proved by Thomas Graham's investigation of the phosphoric acids; for he then showed that the ortho- (ordinary), pyroand metaphosphoric acids contained respectively 3, 2 and I molecules of " basic water " (which were replaceable by metallic oxides) and one molecule of phosphoric oxide, P2 05.
Radiation is a molecular process, and we can speak of the radiation of a molecule but not of its temperature.
The problem, which, in the opinion of the present writer, is the one of interest and has more or less definitely been in the minds of those who have discussed the subject, is whether the type of wave sent out by a molecule only depends on the internal energy of that molecule, or on other considerations such as the mode of excitement.
Considering the great variety of spectra, which one and the same body may possess, the idea lies near that free electrons may temporarily attach themselves to a molecule or detach 'themselves from it, thereby altering the constitution of the vibrating system.
A limit to homogeneity of radiation is ultimately set by the so-called Doppler effect, which is the change of wave-length due to the translatory motion of the vibrating molecule from or towards the observer.
Such spectra seem to be characteristic of complex molecular structure, as they appear when compounds are raised to incandescence without decomposition, or when we examine the absorption spectra of vapours such as iodine and bromine and other cases where we know that the molecule consists of more than one atom.
Each molecule need not radiate with increased energy, but the more brilliant emission of light may be due to the greater number of particles forming similar vibrating systems.
From An M Atomic Molecule We Should Then Have S/S= 2/(2M I).
This Gives A Series Of Ratios 5/3, 7/5, 9/7, Ii/9, &C., For I, 2, 3, 4, &C., Atoms In The Molecule, Values Which Fall Within The Limits Of Experimental Error In Many Cases.
If we suppose that the number of molecules within the range of the attraction of a given molecule is very large, the part of the pressure arising from attraction will be proportional to the square of the number of molecules in unit of volume, that is, to the square of the density.
The energy liberated during the oxidation of the nitrogen is regarded as splitting the carbon dioxide molecule, - in green plants it is the energy of the solar rays which does this.
In the first place, the extremely small size and isolation of the vegetative cells place the protoplasmic contents in peculiarly favourable circumstances for action, and we may safely conclude that, weight for weight and molecule for molecule, the protoplasm of bacteria is brought into contact with the environment at far more points and over a far larger surface than is that of higher organisms, whether - as in plants - it is distributed in thin layers round the sap-vacuoles, or - as in animals - is bathed in fluids brought by special mechanisms to irrigate it.
In other cases such changes cannot be detected, and the only evidence of their occurrence may be the associated symptoms. The very important work of Ehrlich on diphtheria toxin shows that in the molecule of toxin there are at least two chief atom groups - one, the " haptophorous," by which the toxin molecule is attached to the cell protoplasm; and the other the " toxophorous," which has a ferment-like action on the living molecule, producing a disturbance which results in the toxic symptoms. On this theory, susceptibility to a toxin will imply both a chemical affinity of certain tissues for the toxin molecule and also sensitiveness to its actions, and, furthermore, non-susceptibility may result from the absence of either of these two properties.
It may produce a disintegration of the toxin molecule, or it may combine with it to produce a body whose combining affinities are satisfied.
Natural immunity against toxins must be taken into account, and, if Ehrlich's view with regard to toxic action be correct, this may depend upon either the absence of chemical affinity of the living molecules of the tissues for the toxic molecule, or upon insensitiveness to the action of the toxophorous group. It has been shown with regard to the former, for example, that the nervous system of the fowl, which possesses immunity against tetanus toxin, has little combining affinity for it.
Soc. Morphine, or morphia, crystallizes in prisms with one molecule of water; it is soluble in woo parts of cold water and in 160 of boiling water, and may be crystallized from alcohol; it is almost insoluble in ether and chloroform.
Thus 0 2.4 indicates the presence of two double bonds in the molecule situated immediately after the carbon atoms 2 and 4; for example II.
The term "perfect gas" is applied to an imaginary substance in which there is no frictional retardation of molecular motion; or, in other words, the time during which any molecule is influenced by other molecules is infinitesimally small compared with the time during which it traverses its mean free path.
This subject, which is discussed in the article Molecule, has for its purpose (I) the derivation of a physical structure of a gas which will agree with the experimental observations of the diverse physical properties, and (2) a correlation of the physical properties and chemical composition.
The coloration is due to the production of unstable compounds of the ferrous salt and nitric oxide, and it seems that in neutral solutions the compound is made up of one molecule of salt to one of gas; the reaction, however, is reversible, the composition varying with temperature, concentration and nature of the salt.
In the following year he published at Vienna his famous work, Theoria philosophiae naturalis redacta ad unicam legem virium in natura existentium, containing his atomic theory (see MOLECULE).
If, however, a second molecule of a zinc alkyl be allowed to react, a compound is formed which gives a tertiary alcohol when decomposed with water.
As it is we shall find a continuous molecule manifesting attractive and repulsive forces; attraction corresponding to the tendency of the self-preservations to become perfect, repulsion to the frustration of this.
A brief paper entitled "Speculative Ideas on the Constitution of Matter" (1863) possesses special interest in connexion with work done since his death, because in it he expressed the view that the various kinds of matter now recognized as different elementary substances may possess one and the same ultimate or atomic molecule in different conditions of movement.
It crystallizes in colourless prisms with one molecule of water, which redden on exposure.
The conversion of the glycerides (triglycerides) into fatty acids and glycerin must be looked upon as a reaction which takes place in stages, one molecule of a triglyceride being converted first into diglyceride and one molecule of fatty acid, the diglyceride then being changed into monoglyceride, and a second molecule of fatty acid, and finally the monoglyceride being converted into one molecule of fatty acid and glycerin.
The polarizability in cubic angstroms of a molecule in any particular orientation can then easily be calculated.
He was interested in many alkaloids including atropine (1) and the structurally similar cocaine (3) molecule.
An aromatic is a organic compound that contains a benzene ring in is molecule or has very similar chemical properties to benzene.
Whole cell biosensors have also been developed based on 2 component gene systems using gfp as the reporter molecule.
For example, amylase catalyzes the breakdown of starch-based stains to smaller segments that make up the larger starch molecule.
The molecule was named buckminsterfullerene in honor of the architect, who designed geodesic domes based on similar pentagonal and hexagonal structures.
What's more, it also has the most elemental calcium (40% of the total molecule ).
In the addition stage, an ammonia molecule becomes attached to the carbon in the ethanoyl chloride.
Now with close to 40 times more creatine in your muscle cell, the creatine molecule can finally unleash its full potential.
The cyanide ion comes from hydrogen cyanide, which is a covalent molecule.
What causes an excited atom or molecule to emit a photon?
Thus if Dalton's diagram for the molecule, propor- or compound atom, of water be correct, it follows that in all samples of water the total number of the hydrogen atoms is equal to that of the oxygen atoms; consequently, the ratio of the weight of oxygen to that of hydrogen in water is the same as the ratio of the weights of an oxygen and a hydrogen atom, and this is invariable.
If the substituent groups are different, then the molecule will be chiral.
Porphyrin is a large molecule shaped like a four-leaf clover.
Heme-The iron-containing molecule in hemoglobin that serves as the site for oxygen binding.
Ozone-A form of oxygen with three atoms in its molecule (O3), produced by an electric spark or ultraviolet light passing through air or oxygen.
Protein-An important building blocks of the body, a protein is a large, complex organic molecule composed of amino acids.
Red blood cells-Cells that carry hemoglobin (the molecule that transports oxygen) and help remove wastes from tissues throughout the body.
Hemoglobin A-Normal adult hemoglobin that contains a heme molecule, two alpha-globin molecules, and two beta-globin molecules.
Red blood cell-Cells that carry hemoglobin (the molecule that transports oxygen) and help remove wastes from tissues throughout the body.
Normal T cells produce a ligand (a small molecule that links to larger molecules) known as CD40.
Gene therapy involves the insertion of a normal gene into a targeted cell to replace an abnormal gene by means of a vector or carrier molecule.
Ligand-Any type of small molecule that binds to a larger molecule.
Protein-An important building block of the body, a protein is a large, complex organic molecule composed of amino acids.
Immunoglobulin heavy chain deletion, a form of agammaglobulinemia, is a genetic disorder in which part of the antibody molecule is absent.
Normally when a person breathes fresh air into the lungs, the oxygen in the air binds with a molecule called hemoglobin (Hb) that is found in red blood cells.
In the lungs, CO competes with oxygen to bind with the hemoglobin molecule.
Once cholesterol enters the body, a slight alteration in the cholesterol molecule occurs, with one change taking place in the skin.
When enough fluoride from water, supplements, food, or other sources enters the bloodstream and reaches the teeth while the enamel is forming, the fluoride can replace a piece of the hydroxyapatite molecule to form fluorapatite.
From the smallest cross-section of a DNA molecule to the proportion between your height and the distance between your navel and your foot, the Golden Ratio in humans may be the design template of the body.
For example, every molecule of DNA follows the proportions of the Golden Ratio.
Scientists have isolated a molecule that's vital to tail movement and are now trying to find a way to stop that molecule from working.
Belli makes a cream containing darutoside, a plant molecule which is said to help minimize stretch marks.
These pills help increase the amount of a molecule called sex-hormone-binding globulin.
When they find one, they take control of it, thus turning the previously stable molecule into a free radical as well -- again in search of an electron.
Because the body produces K2 on its own, it's rare for people to be deficient -- unless their bodies are unable to absorb the molecule.
Its most important role is in the eye, where it creates a molecule called retinal that is necessary for low light and color vision.
Gluten is a large molecule made up of smaller proteins, namely glutenin and gliadin.
Another consequence of the doctrine of valency was that it permitted the graphic representation of the molecule.
From the fact that reduction products containing either one or two double linkages behave exactly as unsaturated aliphatic compounds, being readily reduced or oxidized, and combining with the halogen elements and haloid acids, it seems probable that in benzenoid compounds the fourth valencies are symmetrically distributed in such a manner as to induce a peculiar stability in the molecule.