of a hormone (angiotensin) that narrows/restricts blood vessels. See also ACE.

Acetolactate Synthase See ALS.

Acetyl Carnitine One of the metabolites of mitochondria, it is a substrate (i.e., substance that is acted upon) for acylcarnitine transferase (which converts the acetyl carnitine to carnitine). Research indicates that consumption of acetyl carnitine helps increase the levels of acetylcholine and nerve growth factor (NGF) in the brain. See also METABOLITE,

MITOCHONDRIA, ACYLCARNITINE TRANSFERASE,

SUBSTRATE (CHEMICAL), CARNITINE, ACETYL-

CHOLINE, NERVE GROWTH FACTOR (NGF).

Acetyl Coenzyme A See Ac-CoA.

Acetyl-CoA Acetyl-coenzyme A. See also

Ac-CoA.

Acetyl-CoA Carboxylase An enzyme that catalyzes the chemical reaction (i.e., conversion of Ac-CoA to malonyl CoA via carboxylation) which is the first step in the series of chemical reactions through which some plants manufacture oils (e.g., soybean oil, canola oil, etc.). See also ENZYME, FATS, SOY-

BEAN OIL, CANOLA.

Acetylcholine A neurotransmitter (i.e., one of several relatively small, diffusible molecules utilized by the human body to “transmit” nerve impulses) that is synthesized (manufactured) near the ends of axons (i.e., one type of neuron). That synthesis is accomplished by the “transfer” of an acetyl group (portion of molecule) from Ac-CoA to a choline molecule (available in the body via consumption of soybean lecithin or certain other foods), in a chemical reaction catalyzed by cholinesterase. Increased amounts of acetylcholine in the (human) brain has been shown to reduce the symptoms of Alzheimer’s dis-

ease. See also NEUROTRANSMITTER, NEURON,

CHOLINE, Ac-CoA, LECITHIN, ALZHEIMER’S DIS-

EASE, THYMUS, ENZYME, CHOLINESTERASE.

Acetylcholinesterase An enzyme that hydrolyzes (cuts into smaller pieces) molecules of the neurotransmitter acetylcholine, after the acetylcholine molecules have accomplished “transmission” of a nerve impulse. That hydrolysis (cutting into pieces) of acetylcholine molecules thus serves to prepare the neurons (cells of the body’s nervous system) to be able to transmit other, later nerve

impulses. See also

NEUROTRANSMITTER, ACETYLCHOLINE, NEURON. A

Acid A substance that contains hydrogen atom(s) in its molecular structure, with a pH in the range from 0–6, which will react with a base to form a salt. Acids normally taste sour and feel slippery. For example, food product manufacturers often add citric acid, malic acid, fumaric acid, and itaconic acid in order to impart a sharp taste to food prod-

ucts. See also BASE, CITRIC ACID, FUMARIC ACID

(C4H4O4).

Acidic Fibroblast Growth Factor (AFGF)

See FIBROBLAST GROWTH FACTOR (FGF).

Acidosis A metabolic condition in which the capacity of the body to buffer changes in pH is diminished. Hence, acidosis is accompanied by decreased blood pH (i.e., the blood becomes more acidic than is normal).

ACP (acyl carrier protein) A protein that binds acyl intermediates during the formation of long-chain fatty acids. ACP is important in that it is involved in every step of fatty acid synthesis. See also FATTY ACID,

ACYL-CoA, FATS.

Acquired Immune Deficiency Syndrome (AIDS) A disease in which a specific virus attacks and kills macrophages and helper T cells (thus causing collapse of the entire immune system). Once the immune system has been inactivated, other diseases, which under normal circumstances can be fought off, become fatal. See also HUMAN IMMUNO-

DEFICIENCY VIRUS TYPE 1 (HIV-1), HUMAN IMMU-

NODEFICIENCY VIRUS TYPE 2 (HIV-2), HELPER

T CELLS (T4 CELLS), MACROPHAGE, TUMOR

NECROSIS FACTOR (TNF).

Acrylamide Gel See POLYACRYLAMIDE GELS.

ACTH [adrenocorticotropic hormone (corticotropin)] A polypeptide secreted by the anterior lobe of the pituitary gland. This is an example of a protein hormone. See also

POLYPEPTIDE (PROTEIN), ENDOCRINE GLANDS,

ENDOCRINE HORMONES.

Activation Energy The amount of energy (calories) required to bring all the molecules in one mole of a reacting substance to the transition state. More simply, it may also be viewed as the energy required to bring reacting molecules to a certain energy state from which point the reaction proceeds spontaneously.

See also TRANSITION STATE (IN A CHEMICAL

AREACTION), MOLE, FREE ENERGY.

Activator A small molecule that stimulates (increases) an enzyme’s catalytic activity when it binds to an allosteric site. See also

ENZYME, EFFECTOR, ALLOSTERIC SITE.

Active Site The region of an enzyme surface that binds the substrate molecule and transforms the substrate molecule into the new (chemical) product (entity). This site is usually located not on a protruding portion of the enzyme, but rather in a cleft or depression. This establishes a controlled environment in which the chemical reaction may

occur. See also CATALYTIC SITE, AGONISTS,

PHARMACOPHORE, SUBSTRATE (CHEMICAL),

ENZYME, ANTAGONISTS.

Active Transport Cell-mediated, energyrequiring translocation of a molecule across a membrane in the direction of increasing concentration (i.e., opposite of natural tendency). See also OSMOTIC PRESSURE.

-Helix See ALPHA HELIX.

A. flavus See ASPERGILLUS FLAVUS.

Activity Coefficient The factor by which the concentration of a solute must be multiplied to give its true thermodynamic activity.

Acuron™ Gene A gene, trademarked by Syngenta AG, that can be inserted into plants via genetic engineering techniques. Inserted into the genome (DNA) of a plant, the gene confers tolerance to herbicide(s) whose active ingredient is protoporphyrinogen oxidase inhibitor (thus, such herbicides are known as PPO inhibitors). See also HERBICIDE-TOLER-

A N T C ROP, GE NE, GENET IC ENGI N E ER ING,

GENOME, DEOXYRIBONUCLEIC ACID (DNA).

Acute Transfection Short-term infection of cells with DNA.

Acyl-CoA Acyl derivatives of coenzyme A (acyl-S-CoA). See also CARNITINE, COENZYME A,

TRYPSIN INHIBITORS.

Acylcarnitine Transferase An enzyme that converts the mitochondrial metabolite acetyl carnitine into carnitine. See also ENZYME,

ACETYL CARNITINE, CARNITINE.

AD An acronym referring to the group of diseases known collectively as Autoimmune Disorders. These include diseases such as multiple sclerosis, lupus, rheumatoid arthritis,

etc. See also AUTOIMMUNE DISEASE, MULTIPLE

SCLEROSIS, LUPUS.

Adaptation Refers to the adjustment of a population of organisms to a changed environment. For example, during the 19th century, the Industrial Revolution caused large black soot deposits on the white bark of certain trees in England. The change in environment resulted in adaptation (e.g., via selective breeding) of a particular indigenous moth population, consisting of a mixture of all-white and all-black members. Because the soot blackened the formerly white bark of the trees on which the moths rested, predatory birds were able to easily catch and eat the all-white members of the population. Thus, there were fewer all-white moths present in the breeding population, and a preponderance of all-black members. During the 20th century, antipollution efforts in England resulted in a cessation of the airborne soot and the return of tree bark to its original white color. Because the predatory birds were now able to catch and eat the all-black members of that moth population more easily, the proportion of all-black and all-white moths in the breeding population once again changed. See also ORGANISM.

Adaptive Enzymes See INDUCIBLE ENZYMES.

ADBF See AZUROPHIL-DERIVED BACTERICIDAL

FACTOR (ADBF).

Additive Genes Genes that interact but do not show dominance (in the case of alleles) or epistasis (if they are not alleles). See also

GENE, ALLELE, DOMINANT ALLELE, EPISTASIS.

Adenylate Cyclase The enzyme (within cells) that catalyzes the synthesis (manufacture) of cyclic AMP. See also CYCLIC AMP.

Adenine A purine base, 6-aminopurine, occurring in ribonucleic acid (RNA) as well as in deoxyribonucleic acid (DNA) and a component of adenosine diphosphate (ADP) and adenosine triphosphate (ATP). Adenine pairs with thymine in DNA and uracil in RNA.

See also BASE (NUCLEOTIDE), BASE PAIR (bp),

RIBONUCLEIC ACID (RNA), DEOXYRIBONUCLEIC

ACID (DNA).

Adenosine Diphosphate (ADP) A ribonucleoside 5′-diphosphate serving as phosphategroup acceptor in the cell energy cycle. See

also CATABOLISM, ADENOSINE TRIPHOSPHATE

(ATP), ADENOSINE MONOPHOSPHATE (AMP).

Adenosine Monophosphate (AMP) A ribonucleoside 5′-monophosphate that is formed by hydrolysis of ATP or ADP. See also

HYDROLYSIS, ADENOSINE DIPHOSPHATE (ADP),

ADENOSINE TRIPHOSPHATE (ATP).

Adenosine Triphosphate (ATP) The major carrier of chemical energy in the cells of all living things on this planet. A ribonucleoside 5′-triphosphate functioning as a phosphategroup donor in the energy cycle of the cell, ATP contains three phosphate/oxygen molecules linked together. When a phosphatephosphate bond in ATP is broken (hydrolyzed), the energy produced can be used by the cell to carry out its functions. Thus, ATP serves as the universal medium of biological energy storage and exchange in living cells.

See also ATPase, ATP SYNTHETASE, HYDROLYSIS,

CYCLIC PHOTOPHOSPHORYLATION, BIOLUMINES-

CENCE, ATP SYNTHASE, ADENOSINE MONOPHOS-

PHATE (AMP).

Adenovirus A type of virus that can infect humans. As with all viruses, it can reproduce only inside living cells (of other host, organisms). Adenovirus causes manufacture of a protein (metabolite) that disables the p53 gene. Because the p53 gene then cannot perform its usual function (i.e., prevention of uncontrolled cell growth caused by virus/DNA damage), the adenovirus takes over and causes the cell to make numerous copies of the virus until the cell dies, thus releasing the virus copies into the body of the host organism to cause further infection.

See also VIRUS, RETROVIRUSES, GENE DELIVERY,

GENE THERAPY, CELL, PROTEIN, p53 GENE, DEOXY-

RIBONUCLEIC ACID (DNA).

Adhesion Molecule From the Latin adhaerere, to stick to, the term adhesion molecule refers to a glycoprotein (oligosaccharide) molecular chain that protrudes from the surface membrane of certain cells, causing cells possessing matching adhesion molecules to adhere to each other. For example, in 1952 Aaron Moscona observed that (harvesting enzyme-separated) chicken embryo cells did not remain separated, but instead coalesced again into an (embryo) aggregate. In 1955,

be mixed (prior to application to weeds) with

Aherbicide (in water), in order to hasten transport of the herbicide’s active ingredient into the weed plant. That is because the herbicide must move from an aqueous (water) environment into one (i.e., the weed plant’s cuticle or “skin”) comprised of lipids/lipophilic molecules, before it can accomplish its task.

See also SURFACTANT, LIPIDS, LIPOPHILIC.

Adjuvant (to a pharmaceutical) Any compound that enhances the desired response by the body to that pharmaceutical. For example, adjuvants such as certain polysaccharides or surface-modified diamond nanoparticles, can be injected along with (vaccine) antigen in order to increase the immune response (e.g., production of antibodies) to a given antigen. Another example is that consumption of grapefruit juice by humans will increase the impact of certain pharmaceuticals. Those pharmaceuticals include some sedatives, antihypertensives, the antihistamine terfenadine, and the immunosuppressant cyclosporine. The adjuvant effect of grapefruit juice is thought to be caused via inhibition of the enzyme cytochrome P4503A4, which catalyzes reactions involved in the metabolism (breakdown) of those pharmaceuticals.

Another example is that consumption of the pharmaceutical known as clopidogrel (commercial name Plavix) by people immediately following a mild heart attack (severe chest pain) — along with aspirin — greatly reduces the risk of death, strokes, and (new, additional) heart attacks, versus taking aspirin alone after a mild heart attack. See also

CELLULAR IMMUNE RESPONSE, HUMORAL IMMU-

NITY, POLYSACCHARIDES, NANOTECHNOLOGY,

ANTIGEN, ANTIBODY, ENZYME, METABOLISM, HIS-

TAMINE, CYCLOSPORINE, CYTOCHROME P4503A4.

ADME Acronym for Absorption, Distribution (within the body), Metabolism, and Elimination of pharmaceuticals. See also ADME

TESTS, IN SILICO SCREENING.

ADME Tests Refers to Absorption, Distribution (within the body), Metabolism, and Elimination tests required by the U.S. Food and Drug Administration (FDA) for approval of new pharmaceuticals or new food ingredients.

See also FOOD AND DRUG ADMINISTRATION

(FDA), ABSORPTION, METABOLISM, INTERMEDIARY

METABOLISM, PHARMACOKINETICS, PHARMACOGE-

NOMICS, CODEX ALIMENTARIUS COMMISSION,

ADME, ADMET, IN SILICO SCREENING.

ADMET Acronym for Absorption, Distribution (within the body), Metabolism, Elimination, Toxicity of pharmaceuticals. See also

ADME TESTING, IN SILICO TESTING.

Adoptive Cellular Therapy The increase in immune response that is achieved by selectively removing certain immune system cells from a (patient’s) body, multiplying them in vitro outside the body to increase their number greatly, then reinserting those (more numerous) immune system cells into the same body. See also CELLULAR IMMUNE

RESPONSE, CELL CULTURE, IN VITRO , GENE DELIV-

ERY, GENE THERAPY, EX VIVO (THERAPY).

Adoptive Immunization The transfer of an immune state from one animal to another by means of lymphocyte transfusions. See also

LYMPHOCYTE.

ADP See ADENOSINE DIPHOSPHATE (ADP).

Adventitious From the Latin adventitius, not properly belonging to. The term can be utilized to refer to: plant shoots emanating from sites other than typical ones (e.g., from a plant’s leaves); a small amount of transgenic grain accidentally mixed into other grain.

See also TRANSGENIC.

Aerobe An organism that requires oxygen to live (respire).

Aerobic Exposed to air or oxygen. An oxygenated environment.

Affinity Chromatography A method of separating a mixture of proteins or nucleic acids (molecules) by specific interactions of those molecules with a component known as a ligand, which is immobilized on a support. If a solution of, say, a mixture of proteins is passed over (through) the column, one of the proteins binds to the ligand on the basis of specificity and high affinity (they fit together like a lock and key). The other proteins in the solution wash through the column because they were not able to bind to the ligand. Once the column is devoid of the other proteins, an appropriate wash solution is passed through the column, which causes the protein/ligand complex to dissociate. The protein is subsequently collected in a highly purified form.

See also CHROMATOGRAPHY, PROTEIN, NUCLEIC