American Type Culture Collection (ATCC)

An independent, nonprofit organization established in 1925 for the preservation and distribution of reference cultures. See also

CELL CULTURE, CULTURE, CULTURE MEDIUM,

TYPE SPECIMEN, CONSULTATIVE GROUP ON INTER-

NATIONAL AGRICULTURAL RESEARCH (CGIAR).

Ames Test A simple bacterial-based carcinogens test that was developed by Bruce Ames in 1961. Although this test evaluates mutagenesis (causation of mutations) in the DNA of bacteria, its results have been utilized to approve or not approve certain compounds for consumption by humans. See

also BIOASSAY, BACTERIA, ASSAY, MUTUAL REC-

OGNITION AGREEMENTS (MRAs), GENOTOXIC CAR-

CINOGENS, CARCINOGEN, PARP.

Amino Acid There are 20 common amino acids, each specified by a different arrangement of three adjacent DNA nucleotides. These are the building blocks of proteins. Joined together in a strictly ordered chain, the sequence of amino acids determines the character of each protein (chain) molecule. The 20 common amino acids are: alanine, arginine, aspartic acid, glutamic acid, glutamine, glycine, histidine, isoleucine, leucine, phenylalanine, proline, serine, threonine, tryptophan, tyrosine, valine, cysteine, methionine, lysine, and asparagine. Note that virtually all of these amino acids (except glycine) possess an asymmetric carbon atom, and thus are potentially chiral in nature. See

also PROTEIN, POLYPEPTIDE (protein), STEREOISOMERS, CHIRAL COMPOUND, MESSENGER RNA

(mRNA), ESSENTIAL AMINO ACIDS, DEOXYRIBO-

NUCLEIC ACID (DNA), ABSOLUTE CONFIGURATION.

Amino Acid Profile Also known as “protein quality,” this refers to a quantitative delineation of how much of each amino acid is contained in a given source of (livestock feed or food) protein. For example, the amino acid profile of soybean meal is matched closest to the profile of amino acids needed for human nutrition, of all protein meals. See

also “IDEAL PROTEIN” CONCEPT, PROTEIN, AMINO ACID, SOYBEAN MEAL, PDCAAS.

Aminocyclopropane Carboxylic Acid Syn-

thase/deaminase See ACC SYNTHASE, ACC.

AMP See ADENOSINE MONOPHOSPHATE (AMP).

	Amphibolic Pathway A metabolic pathway
		A
	used in both catabolism and anabolism. See
	also ANABOLISM, CATABOLISM.
	Amphipathic Molecules Molecules bearing
	both polar and nonpolar domains (within the
	same molecule). Some examples of amphi-
	pathic molecules are wetting agents (SDS),
	and membrane lipids such as lecithin. See
	also MICELLE, REVERSE MICELLE (RM), POLARITY
	(CHEMICAL).
	Amphiphilic Molecules Also known collec-
	tively as amphiphiles, these molecules pos-
	sess distinct regions of hydrophobic (“water
	hating”) and hydrophilic (“water loving”)
	character within the same molecule. When
	dissolved in water above a certain concentra-
	tion (known as the CMC), they are capable
	of forming high molecular weight aggre-
	gates, or micelles. See also CRITICAL MICELLE
	CONCENTRATION, HYDROPHOBIC, HYDROPHILIC,
	MICELLE, REVERSE MICELLE (RM).
	Amphoteric Compound A compound capa-
	ble of both donating and accepting protons
	and thus able to act chemically as either an
	acid or a base.
	Amplicon A specific sequence of DNA pro-
	duced by a DNA-amplification technology
	such as the Polymerase Chain Reaction
	(PCR) technique. See also DEOXYRIBONUCLEIC
	ACID (DNA), SEQUENCE (OF A DNA MOLECULE),
	POLYMERASE CHAIN REACTION (PCR) TECHNIQUE,
	NESTED PCR.
	Amplification The production of additional
	copies of a chromosomal sequence, found as
	either intrachromosomal or extrachromo-
	somal DNA. See also IN VITRO SELECTION.
	Amplified Fragment Length Polymorphism
	Also known by its acronym, AFLP is a
	“DNA marker” utilized in a “genetic map-
	ping” technique which employs the specific
	sequence of bases (nucleotides) in a piece of
	DNA (from an organism). Since the specific
	sequence of bases in their DNA molecules
	is different for each species, strain, variety,
	or individual (due to DNA polymorphism),
	AFLP can be used to “map” those DNA
	molecules (e.g., to assist and speed up plant
	breeding programs). See also GENETIC MAP,
	SEQUENCE (OF A DNA MOLECULE), DEOXYRIBO-
	NUCLEIC ACID (DNA), GENOME, PHYSICAL MAP
	(OF GENOME), MARKER (DNA SEQUENCE),

© 2002 by CRC Press LLC

		MARKER (GENETIC MARKER), POLYMORPHISM
	A
		(CHEMICAL), NUCLEIC ACIDS, NUCLEOTIDE,
		GENETIC CODE.
		Amplimer See AMPLICON.
		Amylase A term that is used to refer to a cat-
		egory of enzymes that catalyzes the chemi-
		cal reaction in which amylose (starch)
		molecules are hydrolytically cleaved (bro-
		ken) to molecular pieces (e.g., the polysac-
		charides maltose, maltotriose, a-dextrin,
		etc.). For example, α-amylase is used to
		break apart corn starch molecules in the first
		step of manufacturing fructose (sweetener
		for soft drinks). Since 1857, amylase has
		been utilized to remove (amylose) starch
		from woven fabrics in the textile industries.
		Modern uses of some amylases include
		enabling the substitution of barley grain for
		malt in the beer brewing process. See also
		ENZYME, STARCH, AMYLOSE, BARLEY, HYDRO-
		LYTIC CLEAVAGE, POLYSACCHARIDES, ALPHA
		AMYLASE INHIBITOR-1.
		Amyloid Protein Precursor (A PP)
		A (collective) set of protein molecules, from
		which are derived Amyloid β Protein (AβP).
		See also PROTEIN, AMYLOID β PROTEIN PRECUR-
		SOR (AβPP).
		Amyloid Protein (A P) A small protein
		that forms plaque in the brains and in the brain
		blood vessels of victims of Alzheimer’s dis-
		ease. AβP forms cation-selective ion channels
		in lipid bilayers (e.g., membranes surround-
		ing cells). This ion channel formation disrupts
		calcium homeostasis, allowing (destructive)
		high concentrations of calcium ions in brain
		cells. See also PROTEIN, AMYLOID β PROTEIN
		PRECURSOR (AβPP), ALZHEIMER’S DISEASE.
		Amyloid Placques See AMYLOID β PROTEIN (AβP).
		Amylopectin The form of starch (molecule)
		that consists of multi-branched polymers,
		containing approximately 100,000 glucose
		units per molecule (polysaccharide). See
		also S T ARC H, POLY MER, GLUCO SE (GLc),
		POLYSACCHARIDES, WAXY CORN.
		Amylose The form of starch that consists of
		unbranched polymers, containing approxi-
		mately 4000 glucose units per molecule
		(polysaccharide). It is present in potatoes at
		23–29% content (variation is thought to be
		caused by different growing conditions). See

also POLYMER, GLUCOSE (GLc), AMYLASE,

POLYSACCHARIDES.

Anabolism The phase of intermediary metabolism concerned with the energy-requiring biosynthesis of cell components from smaller precursor molecules. See also

CATABOLISM, ASSIMILATION, METABOLISM, CELL,

PLASMA MEMBRANE.

Anaerobe An organism that lives in the absence of oxygen and generally cannot grow in the presence of oxygen. The catabolic metabolism of anaerobic microorganisms reduces a variety of organic and inorganic compounds in order to survive (e.g., carbon dioxide, sulfate, nitrate, fumarate, iron, manganese); anaerobes produce a large number of end products of metabolism (e.g., acetic acid, propionic acid, lactic acid, ethanol, methane, etc.). See also CATABOLISM,

METABOLISM, METABOLITE, REDUCTION (IN A

CHEMICAL REACTION), ANAEROBIC.

Anaerobic An environment without air or oxygen. See also ANAEROBE.

Analogue (Analog) A compound (or molecule) that is a (chemical) structural derivative of a parent compound. The word is also used to describe a molecule that may be structurally similar (but not identical) to another, and which exhibits many or some of the same biological functions of the other. For example, the large class of antibiotics known as the sulfa drugs are all analogues of the original synthetic chemical drug (known as Prontosil, which cures streptococcal infections) discovered by the German biologist Gerhart Domagk. His discovery and others made possible a program of further chemical syntheses based upon the original (sulfanilamide) molecular structure and resulted in the large number of sulfonamide (also called “sulfa”) drugs available today. All of the analogue (also analog) sulfa drugs that were patterned after the original sulfanilamide molecular structure may be called sulfanilamide analogues.

Today, analogues are known by man for various vitamins, amino acids, purines, sugars, growth factors, and many other chemical compounds. Research chemists produce analogues of various molecules in order to ascertain the biological role of, or importance

© 2002 by CRC Press LLC

	of, certain structures (within the molecule)	endostatin, it has been shown to cause certain
			A
	to the molecule’s function within a living	cancer tumors in mice to shrink by cutting
	organism. See also BIOMIMETIC MATERIALS,	off the creation of new blood vessels
	RATIONAL DRUG DESIGN, HETEROLOGY, GIBBER-	required to “feed” a growing tumor.
	ELLINS, QUANTITATIVE STRUCTURE-ACTIVITY	Angiostatin acts to halt the creation of new
	RELATIONSHIP (QSAR).	blood vessels by binding to ATP synthase
	ANDA (to FDA) Abbreviated New Drug	(an enzyme needed to initiate new blood ves-
	Application (to the U.S. Food and Drug	sels). See also PROTEIN, ANTIANGIOGENESIS,
	Administration). See also NDA, “TREATMENT”	ENDOSTATIN, CANCER, ATP SYNTHASE, TUMOR.
	IND REGULATIONS, FOOD AND DRUG ADMINISTRA-	Angstrom (Å) 10–8 cm (3.937 × 10–9 inch).
	TION (FDA).	Anion See ION.
	Angiogenesis Formation/development of new	Anneal The process by which the complemen-
	blood vessels in the body. Discovered to be	tary base pairs in the strands of DNA combine.
	triggered and stimulated by angiogenic	See also BASE PAIR (bp), DEOXYRIBONUCLEIC
	growth factors, in the early 1980s. Angio-	ACID (DNA).
	genesis is required for malignant tumors to	Anonymous DNA Marker Refers to a DNA
	metastasize (spread throughout the body),	marker with a clearly identifiable sequence
	because it provides the (newly-created)	variation (i.e., it is detectable by the specific
	blood supply that tumors require. Angiogen-	variation in its DNA sequence, whether or
	esis is also crucial to the development of	not it occurs in or near a coding sequence).
	glaucoma and macular degeneration (major	See also DEOXYRIBONUCLEIC ACID (DNA),
	cause of blindness). The drug Thalidomide	SEQUENCE (OF A DNA MOLECULE), MARKER (DNA
	is a potent inhibitor of angiogenesis, as are	SEQUENCE), MICROSATELLITE DNA.
	the proteins angiostatin and endostatin. See	Antagonists Molecules that bind to certain
	also ANGIOGENIC GROWTH FACTORS, TUMOR, CAN-	proteins (e.g., receptors, enzymes) at a spe-
	CER, METASTASIS, ANTIANGIOGENESIS, CHIRAL	cific (active) site on that protein. The binding
	COMPOUND, ANGIOSTATIN, ENDOSTATIN.	suppresses or inhibits the activity (function)
	Angiogenesis Factors See ANGIOGENIC GROWTH	of that protein. See also RECEPTORS, ACTIVE
	FACTORS.	SITE, CONFORMATION, AGONISTS, ENZYME,
	Angiogenic Growth Factors P r o t e i n s t h a t	ALLOSTERIC ENZYMES.
	stimulate formation of blood vessels (e.g., in	Anterior Pituitary Gland S e e P I T U I T A R Y
	tissue being formed by the body to repair	GLAND.
	wounds). See also FILLER EPITHELIAL CELLS,	Anthocyanidins Natural pigments (flavo-
	FIBROBLAST GROWTH FACTOR (FGF), MITOGEN,	noids) produced in blueberries (genus Vac-
	ANGIOGENIN, ENDOTHELIAL CELLS, TRANSFORM-	cinium), blackberries (Rubus fruticosus),
	ING GROWTH FACTOR-ALPHA (TGF-ALPHA),	cranberries (Vaccinium macrocarpon), cher-
	TRANSFORMING GROWTH FACTOR-BETA (TGF-	ries (genus Prunus), black or purple carrots
	BETA), PLATELET-DERIVED GROWTH FACTOR	(Daucus carota), and some types of grapes.
	(PDGF), ANGIOGENESIS.	Consumption of anthocyanidins by humans
	Angiogenin One of the human angiogenic	has been shown to be beneficial to eyesight
	growth factors, it possesses potent angio-	by aiding the health of the retina. Within the
	genic (formation of blood vessels) activity.	human body, anthocyanidins act as antioxi-
	In addition to stimulating (normal) blood	dants (i.e., “quenchers” of free radicals), so
	vessel formation, angiogenin levels are cor-	consumption apparently reduces the risk of
	related with placenta formation and tumor	some cancers, coronary heart disease, eyesight
	growth (tumors require new blood vessels).	loss, and cataracts. See also PHYTOCHEMICALS,
	See also ANGIOGENIC GROWTH FACTORS, ANGIO-	NUTRACEUTICALS, CAROTENOIDS, ANTIOXIDANTS,
	GENESIS, TUMOR, GROWTH FACTOR.	OXIDATIVE STRESS, CANCER, CORONARY HEART
	Angiostatin An antiangiogenesis (anti-blood-	DISEASE (CHD), INSULIN, PROANTHOCYANIDINS,
	vessel-formation) human protein discovered	FOSHU.
	by Judah Folkman. In combination with	Anthocyanins See ANTHOCYANIDINS.

© 2002 by CRC Press LLC

Anti-Idiotype Antibodies See ANTI-IDIOTYPES.

AAnti-Idiotypes Antibodies to antibodies. In

other words, if a human antibody is injected into rabbits, the rabbit immune systems will recognize the human antibodies as foreign (regardless of the fact that they are antibodies) and produce antibodies against them. To the rabbit, the foreign antibodies represent just another invader or nonself to be targeted and destroyed. Anti-idiotypes mimic antigens in that they are shaped to fit into the antibody’s binding site (in lock-and-key fashion). As such, anti-idiotypes can be used to create vaccines that stimulate production of antibodies to the antigen (that the antiidiotype mimics). This confers disease resistance (to the pathogen associated with that antigen) without the risk that a vaccine using attenuated pathogens entails (i.e., that the pathogen “revives” to cause the disease). See

also ANTIBODY, MONOCLONAL ANTIBODIES

(MAb), ANTIGEN, IDIOTYPE, PATHOGEN, ATTENU-

ATED (PATHOGENS).

Anti-Interferon An antibody to interferon. Used for the purification of interferons. See

also A N T I B O D Y , I N T E R F E R O N S , A F F I N I T Y CHROMATOGRAPHY.

Anti-Oncogenes See ONCOGENES, ANTISENSE

(DNA SEQUENCE).

Antiangiogenesis Refers to impact of any compound that prevents angiogenesis (i.e., formation/development of new blood vessels). Because angiogenesis is required for malignant tumors to grow and/or metastasize (spread), antiangiogenesis was proposed by Judah Folkman in 1970 as a means to combat cancer. Because angiogenesis is required for embryonic development, antiangiogenic drugs inhibit proper development/growth of infants in the womb. Fumagillin, ovalicin, and Thalidomide have been found to possess antiangiogenic properties. Also, the human proteins angiostatin and endostatin. See also

ANGIOGENESIS, ANGIOGENIC GROWTH FACTORS,

TUMOR, CANCER, ANGIOSTATIN, ENDOSTATIN,

GENISTEIN.

Antibiosis Refers to the processes by which one organism produces a substance that is toxic or repellent to another organism (e.g., a parasite) that is attacking the first organism. For example, certain varieties of

corn/maize (Zea mays L.) naturally produce chemical substances in their roots that are toxic to the corn rootworm. See also ANTIBI-

OTIC, BACILLUS THURINGIENSIS (B.t.), CORN, CORN ROOTWORM.

Antibiotic Coined by Selman Waksman during the 1940s, this term refers to organic compounds that are naturally formed and secreted by various species of microorganisms and/or plants. It has a defensive function and is often toxic to other species (e.g., penicillin, originally produced by bread mold, is toxic to numerous human pathogens). Antibiotics generally act by inhibiting protein synthesis, DNA replication, synthesis of cell wall (cytoplasmic membrane) constituents, inhibition of required cell (e.g., bacteria) metabolic processes, and nucleic acid (DNA and RNA) biosynthesis, hence killing the (targeted bacteria) cells involved. Inorganic (e.g., certain metals) molecules may also have antibiotic properties. See also PATHOGEN, MICROORGAN-

ISM, PROTEIN, NUCLEIC ACIDS, PENICILLIN G

(benzylpenicillin), SYMBIOTIC, GRAM STAIN, GRAM-

NEGATIVE, ALLELOPATHY, BACTERIA, GRAM-POSI-

TIVE, CELL, ANTIBIOSIS, AUREOFACIN, PHOTORHAB-

DUS LUMINESCENS, BETA-LACTAM ANTIBIOTICS,

METABOLISM, DEOXYRIBONUCLEIC ACID (DNA),

PLASMA MEMBRANE, RIBONUCLEIC ACID (RNA).

Antibiotic Resistance A property of a cell (e.g.. pathogenic bacteria) that enables it to avoid the effect of an antibiotic that had formerly killed or inhibited that cell. Ways this can occur include: changing the structure of the cell wall (plasma membrane); synthesis (manufacture) of enzymes to inactivate the antibiotic (e.g., penicillinases, which inactivate penicillin); synthesis of enzymes to prevent antibiotic entering cell; and active removal of the antibiotic from the cell. For example, the membrane transporter protein molecules known as ABC transporters are sometimes able to help pathogenic bacteria resist certain antibiotics by transporting out the antibiotic before it can kill the bacteria. The ABC transporter is a V-shaped molecule embedded in the (bacteria) cell’s plasma membrane, with the open end of the “V” pointed toward the interior of the cell. When molecules of certain antibiotics (inside the cell) contact the ABC transporter molecule,

© 2002 by CRC Press LLC