Glossary

acetylcholine:

neurotransmitter with the chemical formula C₇H₁₇NO₃; it assists in communication between nerve cells in the brain and central nervous system

acid rain:

precipitation that has a pH lower than 5.6; term coined by R. A. Smith during the 1870s

activation analysis:

technique that identifies elements present in a sample by inducing radioactivity through absorbtion of neutrons

adenine:

one of the purine bases found in nucleic acids, C₅H₅N₅

adenosine triphosphate (ATP):

molecule formed by the condensation of adenine, ribose, and triphosphoric acid, HOP(O)OH–O–(O)OH–OP(O)OH–OH; it is a key compound in the mediation of energy in both plants and animals

adrenalin:

chemical secreted in the body in response to stress

alchemy:

medieval chemical philosophy having among its asserted aims the transmutation of base metals into gold

aldehyde:

one of the characteristic groups of atoms in organic compounds that undergoes characteristic reactions, generally irrespective of where it occurs in the molecule; the RC(O)H functional group

aliphatic:

having carbon atoms in an open chain structure (as an alkane)

aliquot:

specific volume of a liquid used in analysis

alkaloid:

alkaline nitrogen-based compound extracted from plants

alloy:

mixture of two or more elements, at least one of which is a metal

α subunit:

subunit that exists in proteins that are composed of several chains of amino acids, the first unit in the "counting" of the units

α-particle:

subatomic particle with 2+ charge and mass of 4; a He nucleus

amalgam:

metallic alloy of mercury and one or more metals

amine functional group:

group in which nitrogen is bound to carbon in an organic molecule in which two other groups or hydrogen atoms are bound to nitrogen; major component of amino acids

amino acid residue:

in a protein, which is a polymer composed of many amino acids, that portion of the amino acid that remains to become part of the protein

amino acid sequence:

twenty of the more than five hundred amino acids that are known to occur in nature are incorporated into a variety of proteins that are required for life processes; the sequence or order of the amino acids present determines the nature of the protein

amphetamine:

class of compounds used to stimulate the central nervous system

anabolism:

metabolic process involving building of complex substances from simpler ones, using energy

analgesic:

compound that relieves pain, e.g., aspirin

androgen:

group of steroids that act as male sex hormones

angiotensin:

chemical that causes a narrowing of blood vessels

anhydrous compound:

compound with no water associated with it

anion:

negatively charged chemical unit, like Cl–, CO₃₂–, or NO₃–

anthcyanin:

antioxidant flavanoid that makes raspberries red and blueberries blue

antibody:

protein molecule that recognizes external agents in the body and binds to them as part of the immune response of the body

anticoagulant:

molecule that helps prevent the clotting of blood cells

antiscorbutic:

substance that has an effect on scurvy

apoenzyme:

the protein part of an enzyme that requires a covalently bound coenzyme (a low molecular weight organic compound) or a cofactor (such as a metal ion) for activity

aqueous solution:

homogenous mixture in which water is the solvent (primary component)

aromatic:

having a double-bonded carbon ring (typified by benzene)

asparagine residue:

amino acid asparagine unit as it occurs in a polypeptide chain

atomic mass units:

unit used to measure atomic mass; 1/12 of the mass of a carbon-12 atom

atomic number:

the number of protons in an atomic nucleus, expressed in terms of electric charge; it is usually denoted by the symbol Z

atomic orbital:

mathematical description of the probability of finding an electron around an atom

atomic spectrum:

electromagnetic array resulting from excitement of a gaseous atom

atomic theory:

concept that asserts that matter is composed of tiny particles called atoms

atomic weight:

weight of a single atom of an element in atomic mass units (amu)

attraction:

force that brings two bodies together, such as two oppositely charged bodies

axial bond:

covalent bond pointing along a molecular axis

azo dye:

synthetic organic dye containing a –N=N– group

bacteriophage multiplication:

process by which immune system cells responsible for battling bacterial infections reproduce

basal metabolism:

the process by which the energy to carry out involuntary, life-sustaining processes is generated.

β subunit:

subunit that exists when two or more polypeptide chains associate to form a complex functional protein, the chains are referred to as "subunits"; these subunits are often identified as α, β, etc.

biological stain:

dye used to provide contrast among and between cellular moieties

biomass:

collection of living matter

biosynthesis:

formation of a chemical substance by a living organism

boat conformation:

the arrangement of carbon atoms in cyclohexane, C₆H₁₂. In which the spatial placement of the carbon atoms resembles a boat with a bow and a stern

brine:

water containing a large amount of salts, especially sodium chloride (NaCl)

Brownian motion:

random motion of small particles, such as dust or smoke particles, suspended in a gas or liquid; it is caused by collisions of the particle with gas or solvent molecules which transfer momentum to the particle and cause it to move

calc:

calcium carbonate

calcine:

to heat or roast to produce an oxide (e.g., CaO from calcite)

capacitor plate:

one of several conducting plates, or foils, in a capacitor, separated by thin layers of dielectric constant, an insulating material

carboxylate:

structure incorporating the –COO– group

carboxyl group:

an organic functional group, –C(O), found in aldehydes, ketones, and carboxyl acids.

carboxylic acid:

one of the characteristic groups of atoms in organic compounds that undergoes characteristic reactions, generally irrespective of where it occurs in the molecule; the –CO₂H functional group

catabolism:

metabolic process involving breakdown of a molecule into smaller ones resulting in a release of energy

catalysis:

the action or effect of a substance in increasing the rate of a reaction without itself being converted

catalyst:

substance that aids in a reaction while retaining its own chemical identity

catalytic conversion:

catalytic oxidation of carbon monoxide and hydrocarbons in automotive exhaust gas to carbon dioxide and water

cell culture:

artificially maintained population of cells, grown in a nutrient medium and reproducing by asexual division

cephalosporin C:

family of antibiotics obtained from a fungus acting in a manner similar to penicillin

chain of custody:

sequence of possession through which evidentiary materials are processed

chair conformation:

arrangement of atoms in a cycle structure (usually a sixmembered ring) that appears to be arranged like a chair (as opposed to the other conformation which is described as a "boat")

chemical-gated:

of a membrane protein whose action to open a pore in the membrane occurs only after a substrate has been binded to the protein or a cofactor

chlorofluorocarbon (CFC):

compound containing carbon, chlorine, and fluorine atoms that remove ozone in the upper atmosphere

chlorophyll:

active molecules in plants undergoing photosynthesis

chromatography:

the separation of the components of a mixture in one phase (the mobile phase) by passing in through another phase (the stationary phase) making use of the extent to which the components are absorbed by the stationary phase

chromophore:

part of the molecule that yields characteristic colors

cladding:

protective material surrounding a second material, which is frequently tubes filled with uranium dioxide pellets in a nuclear reactor

cleave:

split

cobrotoxin:

polypeptide toxin containing sixty-two residues that is found in the venom of cobras

code:

mechanism to convey information on genes and genetic sequence

cofactor:

inorganic component that combines with an apoenzyme to form a complete functioning enzyme

coherent mass:

mass of particles that stick together

color fastness:

condition characterized by retention of colored moieties from a base material

combustion:

burning, the reaction with oxygen

competitive inhibitor:

species or substance that slows or stops a chemical reaction

complementarity:

basis for copying the genetic information, where each nucleotide base has a complementary partner with which it forms a base-pair

congener:

an element or compound belonging to the same class

constitutional isomer:

form of a substance that differs by the arrangement of atoms along a molecular backbone

contact activity:

process involving the touching of different surfaces

contraction:

the shortening of a normal trend of a quantity

coordinate covalent bond:

covalent bond in which both of the shared electrons originate on only one of the bonding atoms

coordination chemistry:

chemistry involving complexes of metal ions surrounded by covalently bonded ligands

corrosive gas:

gas that causes chemical deterioration

covalent bond:

bond formed between two atoms that mutually share a pair of electrons

crystal lattice:

three-dimensional structure of a crystaline solid

crystallization:

process of producing crystals of a substance when a saturated solution in an appropriate solvent is either cooled or some solvent removed by evaporation

culture:

living material developed in prepared nutrient media

cyanobacterium:

eubacterium sometimes called "the blue-green alga"; it contains chlorophyll (the pigment most abundant in plants), has very strong cell walls, and is capable of photosynthesis

cyclopentadienyl ring:

five-membered carbon ring containing two C–C double bonds; formula C₅H₆

cysteine residue:

sulfhydryl-containing cysteine unit in a protein molecule

cytosine:

heterocyclic, pyrimidine, amine base found in DNA

dedifferentiation:

the opposite of the biological process of differentiation by which a relatively unspecialized cell undergoes a progressive change to a more specialized form or function

degradative:

relating to or tending to cause decomposition

degrade:

to decompose or reduce the complexity of a chemical

delocalized:

of a type of electron that can be shared by more than one orbital or atom

denitrification:

process of removing nitrogen

density-functional theory:

quantum mechanical method to determine ground states

depolarization:

process of decreasing the separation of charge in nerve cells; the opposite of hyperpolarization

deterministic:

related to the assumption that all events are based on natural laws

deuteron:

nucleus containing one proton and one neutron, as is found in the isotope deuterium

dialcohol:

organic molecule containing two covalently-bonded –OH groups

diamagnetic:

property of a substance that causes it to be repelled by a magnetic field

diamine:

compound, the molecules of which incorporate two amino groups (–NH₂) in their structure, such as 1,2 diamino ethane (sometimes called ethylenediamine) and the three diamine benzene compounds

dibasic acid:

acidic substance that incorporates two or more acidic hydrogen atoms in one molecule, such as sulfuric (H₂SO₄) and phosphoric (H₃PO₄) acids

dihydroxy compound:

compound with molecules that incorporate two hydroxyl groups (–OH) in their structure, such as 1,2 dihydroxy ethane (sometimes called glycol) and the three dihydroxy benzene compounds

directing effect:

ability of a functional group to influence the site of chemical reaction, such as substitution, for a molecule

discharge display tube:

glass tube containing gas at low pressure through which a beam of electrons is passed

disperse system:

two-phase system in which one phase, the disperse phase, is distributed in the second phase, the dispersion medium

disulfide bond:

bond in a complex substance that involves two bonding sulfur atoms, –S–S–

disulfide bridge:

covalent –S–S– linkage that provides cross-links in protein molecules

DNA:

deoxyribonucleic acid—the natural polymer that stores genetic information in the nucleus of a cell

dope:

to add a controlled amount of an impurity to a very pure sample of a substance, which can radically change the properties of a substance

drug resistance:

ability to prevent the action of a particular chemical substance

ductile:

property of a substance that permits it to be drawn into wires

Eighteen Electron Rule:

rule noting that coordination complexes with eighteen electrons are stable; electrons from both metal species and ligand donor species are counted

electrolyte solution:

a liquid mixture containing dissolved ions

electron correlation error:

quantum mechanical method for studying atoms, ions, or molecules

electronegative:

capable of attracting electrons

electrophoresis:

migration of charged particles under the influence of an electric field, usually in solution; cations, the positively charged species, will move toward the negative pole and anions, the negatively charged species, will move toward the positive pole

electrostatic interaction:

force that arises between electrically charged particles or regions of particles

elemental analysis:

determination of the percent of each atom in a specific molecule

emulsifier:

substance that stabilizes the formation of an emulsion—normally it contains molecules with both polar and non-polar functional groups

emulsion:

immiscible two-phase mixture in which one phase is dispersed (as small droplets) in the other phase

enantiomorphic shape:

mixture of molecules with the same molecular formulas but different optical characteristics

endohedral:

descriptive term for a point within a three-dimensional figure

endoplasmic reticulum:

internal membrane system that forms a net-like array of channels and interconnections of organelles within the cytoplasm of eukaryotic cells

Equation of State for Ideal Gases:

mathematical statement relating conditions of pressure, volume, absolute temperature, and amount of substance; PV = nRT

equatorial bond:

covalent bond perpendicular to a molecular axis

equilibrium:

condition in which two opposite reactions are occurring at the same speed, so that concentrations of products and reactants do not change

erythromycin:

antibiotic used to treat infections

ester:

organic species containing a carbon atom attached to three moieties: an O via a double bond, an O attached to another carbon atom or chain, and an H atom or C chain; the R(C=O)OR functional group

esterification:

chemical reaction in which esters (RCO₂R₁) are formed from alcohols (R₁OH) and carboxylic acids (RCO₂R′)

estrogen:

female sex hormone

eukaryotic cell:

cell characterized by membrane-bound organelles, most notably the nucleus, and that possesses chromosomes whose DNA is associated with proteins

excitatory:

phenomenon causing cells to become active

excitatory neurotransmitter:

molecule that stimulates postsynaptic neurons to transmit impulses

exclusion principle:

principle that states that no two electrons can have the same four quantum numbers

excrete:

to eliminate or discharge from a living entity

expressed:

made to appear; in biochemistry—copied

extracellular matrix:

entity surrounding mammalian tissue cells, also called connective tissue; composed of structural proteins, specialized proteins, and proteoglycans

face centered cubic structure:

close-packed crystal structure having a cubic unit cell with atoms at the center of each of its six faces

feedstock:

mixture of raw materials necessary to carry out chemical reactions

Fermi conduction level:

vacant or partially occupied electronic energy level resulting from an array of a large number of atoms in which electrons can freely move

ferric:

older name for iron in the +3 oxidation state

ferrous:

older name for iron in the +2 oxidation state

fibril:

slender fiber or filament

fission:

process of splitting of an atom into smaller pieces

fissionable:

of or pertaining to unstable nuclei that decay to produce smaller nuclei

5′ end:

situation in nucleic acids in which the phosphate group is attached at the fifth carbon atom from where the base is attached

folic acid:

pteroylglutamic acid; one of the B complex vitamins

formaldehyde:

name given to the simplest aldehyde HC(O)H, incorporating the –C(O)H functional group

fractional distillation:

separation of liquid mixtures by collecting separately the distillates at certain temperatures

fulcrum:

prop or support to an item as in a lever

functional group:

portion of a compound with characteristic atoms acting as a group

galactose:

six-carbon sugar

galvanic:

relating to direct current electricity, especially when produced chemically

galvanometer:

instrument used to detect and measure the strength of an electric current

gas density:

weight in grams of a liter of gas

glucocorticoid:

class of hormones that promotes the breakdown of proteins to make amino acids available for gluconeogenesis; this elevates the blood sugar level and leads to glycogen synthesis in the liver

glucose:

common hexose monosaccharide; monomer of starch and cellulose; also called grape sugar, blood sugar, or dextrose

golgi apparatus:

collection of flattened stacks of membranes in the cytoplasm of eukaryotic cells that function in the collection, packaging, and distribution of molecules synthesized in the cell

gram negative:

bacteria that do not retain their color when exposed to basic dyes such as crystal violet and then exposed to organic solvents; named after Danish bacteriologist Hans Christian Joachim Gram

gram positive:

bacteria that retain their color when exposed to basic dyes such as crystal violet and then exposed to organic solvents; named after Danish bacteriologist Hans Christian Joachim Gram

Gray:

unit of radiation dose per second; 1 Gray = 1 J/kg

greenhouse effect:

presence of carbon dioxide in the atmosphere prevents heat from escaping, thereby raising Earth's temperature

Griess reagent:

solution of sulfanilic acid and a-naphthylamine in acetic acid; reagent for nitrites

guanine:

heterocyclic, purine, amine base found in DNA

halogen:

element in the periodic family numbered VIIA (or 17 in the modern nomenclature) that includes fluorine, chlorine, bromine, iodine, and astatine

heavy metal:

by convention, a metal with a density greater than 5 g/cm³; 70 elements are thus classified as heavy metals

helix:

in the shape of a spiral or coil, such as a corkscrew

heme group:

functional group formed by an iron atom interacting with a heterocyclic ligand called a porphyrin

hemiacetal:

relating to organic compounds formed from an alcohol and a carbonyl-containing molecule

hemlock:

poisonous herb of the genus Conium

Hippocrates:

Greek physician of fifth century B.C.E. known as the "father of medicine"

homogeneous:

relating to a mixture of the same materials

homogeneous solution:

mixture of molecules that forms a single phase (solid, liquid, or gas)

hormonal signaling:

collective processes by which hormones circulate in the blood stream to their target organs and trigger the desired responses

hydrogen bonding:

intermolecular force between the H of an N–H, O–H or F–H bond and a lone pair on O, N or F of an adjacent molecule

hydrolyze:

to react with water

hydrophilic:

having an affinity with water

hydrophobic:

water repelling

hyperbolic relationship:

a geometric system in which two or more lines can be drawn through any point in a plane and not intersect a given line in that plane

hyperpolarization:

process of causing an increase in charge separation in nerve cells; opposite of depolarization

hypertension:

condition in which blood pressure is abnormally high

Ibn Sina:

given name of an Islamic scientist known in the West as Avicenna (979–1037); reputed to be the author of more than 100 books that were Europe's most important medical texts from the 12th century until the 16th century

inert:

incapable of reacting with another substance

inhibitory:

preventing an action that would normally occur

integro-differential:

complex mathematical model used to calculate a phase transition

interface tension:

contractile force at the junction of two liquids

intermediate:

molecule, often short-lived, that occurs while a chemical reaction progresses but is not present when the reaction is complete

intermolecular force:

force that arises between molecules, generally it is at least one order of magnitude weaker than the chemical bonding force

internuclear:

distance between two nuclei

intestinal epithelium:

layer of cells in the intestines that allows the passage of water and solutes

intramolecular force:

force that arises within molecules—essentially the force associated with chemical bonds

invertebrate:

category of animal that has no internal skeleton

in vitro:

Latin, meaning "in glass" and applied to experiments done under artificial conditions, that is, in a test tube

in vivo:

Latin, meaning "in life" and applied to experiments conducted in a living cell or organism

ion exchange chromatography:

form of liquid-solid chromatography based on the reversible formation of bonds between the fixed ions bound to an insoluble matrix of an ion exchanger and mobile counter ions present in the liquid phase passing over the insoluble matrix

ionization:

dissociation of a molecule into ions carrying + or − charges

isolate:

part of a reaction mixture that is separated and contains the material of interest

isomer:

molecules with identical compositions but different structural formulas

isoprene:

common name for 2-methyl-1,3butadiene, the monomer of the natural rubber polymer

isostructural:

relating to an arrangement of atomic constituents that is geometrically the same although different atoms are present

isotope:

form of an atom that differs by the number of neutrons in the nucleus

ketone:

one of the characteristic groups of atoms in organic compounds that undergoes characteristic reactions, generally irrespective of where it occurs in the molecule; the RC(O)R functional group

kinetic theory:

theory of molecular motion

Kohlrausch drum:

rotating cylinder used to mount a variable resistance slide wire for a polarograph

lanthanides:

a family of elements (atomic number 57 through 70) from lanthanum to lutetium having from 1 to 14 4f electrons

lattice:

systematic geometrical arrangement of atomic-sized units that describe the structure of a solid

ligand:

molecule or ion capable of donating one or more electron pairs to a Lewis acid

lipid:

a nonpolar organic molecule; fatlike; one of a large variety of nonpolar hydrophobic (water-hating) molecules that are insoluble in water

lipophilic:

a molecule that tends to congregate in solution with lipids—it will be a nonpolar molecule or the nonpolar portion of a molecule

liposome:

sac formed from one or more lipid layers that can be used for drug transport to cells in the body

liquefaction:

process of changing to a liquid form

locomotor:

able to move from place to place

Lucretius:

Roman poet of first century B.C.E., also known as Titus Carus; author of De Rerum Natura

lysergic acid:

one of the Ergot series of alkaloids, which constrict blood vessels so that the victim develops burning sensations in the limbs, gangrene, and, ultimately, convulsions; the diethylamide of this substance (LSD) induces visual perception disorders, delusion

lysis:

breakdown of cells; also the favorable termination of a disease

macrolide:

substance with a large ring lactone structure

macronutrient:

one of a number of substances, needed in relatively large amounts, that provide nourishment for living organisms

macroscopic phenomena:

events observed with human vision unassisted by instrumentation

mammalian toxicity:

poisonous effect on humans and other mammals

Manhattan Project:

government project dedicated to creation of an atomic weapon; directed by General Leslie Groves

manifold of ensemble states:

a set of quantum states that meet the specific requirements (such as total energy) being considered in a calculation

mechanical energy:

energy of an object due to its position or motion

mediate:

to act as an intermediary agent

melting point:

temperature at which a substance in the solid state undergoes a phase change to the liquid state

mentorship:

the process by which a wise and trusted teacher guides a novice in the development of his/her abilities

metabolism:

the complete range of biochemical processes that take place within living organisms; comprises processes that produce complex substances from simpler components, with a consequent use of energy (anabolism), and those that break down complex food molecules, thus liberating energy (catabolism)

metabolites:

products of biological activity that are important in metabolism

metal:

element or other substance the solid phase of which is characterized by high thermal and electrical conductivities

metal cation:

positively charged ion resulting from the loss of one or more valence electrons

metalloenzyme:

a protein enzyme that contains at least one metal atom, often in an active site of the protein

metalloid:

elements that exhibit properties that are between those of metals and nonmetals; generally considered to include boron, silicon, germanium, arsensic, antimony, tellurium, and polonium

metallothionein:

class of low molecular weight proteins and polypeptides with very high metal and sulfur content; thought to play a role in concentration and flow of essential elements, e.g., Cu and Zn, and in ameliorating the influence of toxic elements, e.g., Hg and Cd, in the body

metallurgy:

the science and technology of metals

microchemistry:

chemical investigation carried out on a microscopic level

microcrystalline:

relating to the structure of crystals of very small size, typically a micron (μm) in dimension

micromolar:

relating to a solution of a substance that is in the concentration range of micromoles per liter, or 10⁻⁶ moles per liter

mitochondrial matrix:

soluble phase inside the inner mitochondrial membrane containing most of its enzymes

mitosis:

process by which cells divide, particularly the division of the cell nucleus

molecular identity:

"fingerprint" of a molecule describing the structure

monoclinic:

one of several arrangements of atoms found in crystalline solids; characterized by a unit cell of three axes each of a differing length; two axes are mutually perpendicular while the third is at an oblique angle

monodentate:

capable of donating one electron pair; literally, one-toothed

monosaccharide:

one class of the natural products called carbohydrates with the general formula C_x(H₂O)_y; monosaccharides have a weak sweet taste, are readily soluble in water, and are called sugars

mordant dye:

dye substance containing an acidic moiety, e.g., a carboxyl group, which binds metallic compounds, forming insoluble colored compounds

natural philosophy:

study of nature and the physical universe

nesosilicate:

any silicate in which the SiO₄ tetrahedra are not interlinked

net charge:

total overall charge

neurologic:

of or pertaining to the nervous system

neuropathy:

degenerative state of the nerves or nervous system

neuropeptide:

neurotransmitter released into the blood stream via nerve cells

neutron activation analysis:

method for detecting traces of elements by bombardment with high-flux neutrons and then measuring the decay rate of the radioactive products

Newtonian:

based on the physics of Isaac Newton

nicotine adenine dinucleotide (NAD):

one compound of a group of coenzymes found in hydrogen-transferring enzymes

nitric oxide:

compound, NO, which is involved in many biological processes; the drug Viagra enhances NO-stimulation of pathways to counteract impotence; may be involved in killing tumors

nitrotoluic acid:

benzoic acid molecule with methyl and nitro groups attached

noble gas:

element characterized by inert nature; located in the rightmost column in the Periodic Table

noncovalent:

having a structure in which atoms are not held together by sharing pairs of electrons

noncovalent aggregation:

non-specific interaction leading to the association of molecules

nonpolar:

molecule, or portion of a molecule, that does not have a permanent, electric dipole

nuclear:

(a) having to do with the nucleus of an atom; (b) having to do with the nucleus of a cell

nucleosynthesis:

creation of heavier elements from lighter elements via fusion reactions in stars

octahedral:

relating to a geometric arrangement of six ligands equally distributed around a Lewis acid; literally, eight faces

odd chain fatty acid:

long chain carboxylic acid with an odd number of carbon atoms

oligomeric chain:

chain that contains a few repeating units of a growing polymeric species

opioid:

naturally produced opium-like substance found in the brain

optically active:

capable of rotating the plane of plane-polarized light

organoleptic:

effect of a substance on the five senses

organometallic compound:

compound containing both a metal (transition) and one or more organic moieties

oxidation:

process that involves the loss of electrons (or the addition of an oxygen atom)

oxidation state zero:

condition characterized by an atom having neither lost nor gained electrons

oxidation–reduction reaction:

reaction, sometimes called redox, that involves the movement of electrons between reactants to form products

oxide ion conductor:

series of oxides of various compounds in perovskite structure—especially of interest in high-temperature fuel cells

parabolic curve:

planar curve each point of which is equidistant from a straight line (axis)

paraffin:

saturated aliphatic hydrocarbon (alkane), or hydrocarbon wax

partial pressure:

portion of a total pressure of a gas mixture contributed by a single type of gas in the sample

passive diffusion:

mechanism of transporting solutes across membranes

pasteurization:

process of heating foods such as milk to destroy bacteria

peerage:

a body of peers; dignitaries of equal standing

perpendicular:

condition in which two lines (or linear entities like chemical bonds) intersect at a 90-degree angle

pH effect:

effect caused by a change in the concentration of hydrogen ions

phase:

homogenous state of matter

phenol:

common name for hydroxybenzene (C₆H₅OH)

phosphorylation:

the addition of phosphates into biological molecules

photodiode assembly:

grouping of electronic devices which includes a photodiode—a photodetector; useful in medical diagnostics, bar code readers, and guidance systems

photon:

a quantum of electromagnetic energy

photosynthesis:

process by which plants convert carbon dioxide and water to glucose

physostigmine:

alkaloid derived from the leaves of the Calabar bean, formula C₁₅H₁₂N₃O₂; salts used for anticholinesterase activity

pilot plant:

intermediate stage of testing for chemical process, between bench-top and production scale

planar complex:

arrangement of atoms in which all atoms lie within a common two-dimensional plane

plane polorized light:

electromagnetic radiation (light) in which the electric (or magnetic) vectors are all vibrating in the same plane

platelet:

smallest noncellular component of human blood

pneumatic chemist:

early chemist who studied primarily the properties of gases

polynucleotide synthesis:

formation of DNA or RNA

polypeptide:

compound containing two or more amide units—C(O)NH—produced by the condensation of two or more amino acids

porphyrin:

common type of heterocyclic ligand that has four five-member rings with a nitrogen, all of which lie in a plane; nitrogen atom lone pairs are available for coordinate covelent bonds

postsynaptic neuron:

receptor nerve cell

potash:

the compound potassium oxide, K₂O

precipitation:

process of separating a solid substance out of a solution

precursor molecule:

molecule that is the chosen starting point for the preparation of another molecule; a starting molecule in a chemical synthesis; a reactant molecule

primary electrochemical cell:

voltaic cell based on an irreversible chemical reaction

principal oxidation state:

oxidation state that is most important

prism:

triangular-shaped material made from quartz or glass used to diffract light

prodrug:

precursor of a drug that is converted into an active form by a metabolic process

progesterone:

steroid found in the female reproductive system; formula C₂₁H₃₀O₂

prokaryotic:

relating to very simple cells of the type found in bacteria

propagating:

reproducing; disseminating; increasing; extending

protecting group:

substance added to a functional group of a molecule preventing further reaction until the substance is removed by subsequent reactions

proximate percent:

nearest percent of a population (e.g. people, substances)

purine base:

one of two types of nitrogen bases found in nucleic acids

putative:

commonly believed or hypothesized

pyramidal:

relating to a geometric arrangement of four electron-donating groups at the four vertices of a pyramid

pyrimidine base:

one of two types of nitrogen bases found in nucleic acids

pyruvate:

anion of pyruvic acid produced by the reaction of oxygen with lactic acid after strenuous exercise

quantum:

smallest amount of a physical quantity that can exist independently, especially a discrete amount of electromagnetic energy

quantum mechanical:

theoretical model to describe atoms and molecules by wave functions

quantum physics:

physics based on the fact that the energy of an electron is equal to its frequency times Planck's constant

radioactive decay:

process involving emission of subatomic particles from a nucleus, typically accompanied by emission of very short wavelength electromagnetic radiation

radioelement:

a radioactive element; one in which the nucleus spontaneously decomposes (decays) producing α (alpha) and β (beta) particles and γ (gamma) rays

rare earth elements:

older name for the lanthanide series of elements, from lanthanum to lutetium

rate-limiting step:

slowest step in a complex reaction; it determines the rate of the overall reaction; sometimes called the rate-determining step

reagent:

chemical used to cause a specific chemical reaction

receptor:

area on or near a cell wall that accepts another molecule to allow a change in the cell

reducing agent:

substance that causes reduction, a process during which electrons are lost (or hydrogen atoms gained)

reducing potential:

stored energy capable of making a chemical reduction occur

relativistic calculation:

quantum mechanical model that includes the effects of relativity, particularly for core electrons

repulsive force:

force that repels two bodies; charges of the same sign repel each other

reserpine:

one of a group of alkaloids found naturally in the shrub Rarewolfia serpentina; has been used for centuries to treat hypertension, insomnia, and mental disorders; more recently it has been used to reduce blood pressure

retardation:

to slow down a chemical reaction

retrosynthetic analysis:

method of analyzing chemical reactions that starts with the product and works backward to determine the initial reactants

reverberator furnace:

furnace or kiln used in smelting that heats material indirectly by deflecting a nearby flame downward from the roof

ribosome:

large complex of proteins used to convert amino acids into proteins

RNA:

ribonucleic acid, a natural polymer used to translate genetic information in the nucleus into a template for the construction of proteins

RNA polymerase:

enzyme used to make RNA using DNA as a template

rough endoplasmic reticulum:

regions of endoplasmic reticulum the outer surfaces of which are heavily studded with ribosomes, which make proteins for activities within membrane-bounded organelles

Royal Society:

The U.K. National Academy of Science, founded in 1660

rutile:

common name of TiO₂; also a common structural type for compounds with the general composition AB₂

saltpeter:

potassium nitrate; chile saltpeter is sodium nitrate

screen:

process of comparing multiple reagents simultaneously to provide information on reaction of one reagent with another

seed germination:

beginning of the process by which a seed produces a new plant

selenium toxicity:

condition created by intake of excess selenium (Se) from plants or seleniferous water; acute and chronic toxicity are known

semisynthetic:

produced by synthesis from natural starting materials

serology:

the study of serum and reactions taking place within it

sigma plus pi bonding:

formation of a double bond within a molecule or ion

single Slater determinant:

wave function used to describe atoms and molecules

size of the basis set:

number of relatively simple mathematical functions (called the basis set) used to represent a more complicated mathematical function such as an atomic orbital

smelting:

process by which ores are reduced in the production of metals

Socrates:

Greek philosopher, c.470–399B.C.E.

somatic cell:

cells of the body with the exception of germ cells

spectral line:

line in a spectrum representing radiation of a single wavelength

spectroscopy:

use of electromagnetic radiation to analyze the chemical composition of materials

spinel:

name given to a group of minerals that are double oxides of divalent and trivalent metals, for example, MgO · Al₂O₃ or MgAl₂O₄; this mineral is called spinel; also a structural type

stacking interactions:

one type of interaction that affects conformation of double-stranded DNA; caused by van der Waals forces

stereospecific:

yielding one product when reacted with a given compound but the opposite product when reacted with its stereoisomer

steric repulsion:

repulsive force that exists when two atoms or groups get too close together

sterol:

steroid containing an alcohol group; derived from plants or animals;e.g., cholesterol

stigmasterol:

sterol found in soybeans, C₂₉H₄₈O

stratosphere:

layer of the atmosphere where ozone is found; starts about 6.2 mi (10 km) above ground

streptomycin:

antibiotic produced by soil bacteria of genus Streptomyces

subcritical:

mass of nuclear materials below the amount necessary to cause a chain reaction

subshell:

electron energy sublevel, of which there are four: s, p, d, and f

sulfonamides:

first of a series of drugs used for the prevention and cure of bacterial infections in humans; sulfanomides are amides of sulfuric acids and contain the –SO₂NRR₁ group

super-heavy elements:

elements of atomic number greater than 103

superhelix:

helical-shaped molecule synthesized by another helical-shaped molecule

surfactants:

surface-active agents that lower the surface tension of water; e.g., detergents, wetting agents

synaptic cleft:

tiny space between the terminal button of one neuron and the dendrite or soma of another

synthesis:

combination of starting materials to form a desired product

synthon:

in retrosynthesis, molecules are broken into characteristic sections called synthons

tetrachloride:

term that implies a molecule has four chlorine atoms present

tetravalent oxidation state:

bonding state of an atom that can form four bonds

theoretical physics:

branch of physics dealing with the theories and concepts of matter, especially at the atomic and subatomic levels

3′ end:

situation in nucleic acids in which the phosphate group is attached at the third carbon atom from where the base is attached

thykaloid membrane:

part of a plant that absorbs light and passes the energy on to where it is needed

thymine:

one of the four bases that make up a DNA molecule

toluic acids:

methylbenzoic acids

torsion balance:

instrument used to measure small forces (weights), based upon the resistance of a wire to be twisted

toxicology:

division of pharmacology dealing with poisons, their identification, detection, effects on the body, and remedies

toxin:

poisonous substance produced during bacterial growth

trace element:

element occurring only in a minute amount

transcription:

enzyme-catalyzed assembly of an RNA molecule complementary to a strand of DNA

transition metal complex:

species formed when a transition metal reacts with ions or molecules, including water

transition metals:

elements with valence electrons in d-sublevels; frequently characterized as metals having the ability to form more than one cation

translational process:

transfer of information from codon on mRNA to anticodon on tRNA; used in protein synthesis

trigonal bipyramidal:

geometric arrangement of five ligands around a central Lewis acid, with ligands occupying the vertices of two trigonal pyramids that share a common face; three ligands share an equatorial plane with the central atom, two ligands occupy an axial position

tropocollagen:

fibers, or fibrils, consisting of three polypeptide sequences arranged in a helix

tyrosine:

one of the common amino acids

ultraviolet radiation:

portion of the electromagnetic spectrum with wavelengths shorter than visible but longer than x rays

uracil:

heterocyclic, pyrimidine, amine base found in RNA

valence:

combining capacity

vertabrates:

animals that have a skeleton

vesicle:

small compartment in a cell that contains a minimum of one lipid bilayer

vitamins:

organic molecules needed in small amounts for the normal function of the body; often used as part of an enzyme catalyzed reaction

vitriol:

sulfate of a metal; there are blue (Cu), white (Zn), green (Fe), and rose (Co) vitriols

volatile:

low boiling, readily vaporized

voltage:

potential difference expressed in volts

vulcanized rubber:

chemical process of mixing rubber with other materials like sulfur; it strengthens rubber so it can be used under hot or cold conditions; discovered by Charles Goodyear

wetting agent:

molecule that, when added to a liquid, facillitates the spread of the liquid across a surface

zoology:

branch of biology concerned with the animal kingdom

zwitterion:

molecule that simultaneously contains a positive and a negative charge