Biotechnology

CRC   PR E S S
Boca Raton   London   New York   Washington, D.C.
K imba ll   Nill
T H I R d   e di t io n
GLOSSARY OF
BIOTECHNOLOGY
TER MS
© 2002 by CRC Press LLC

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International Standard Book Number 1-58716-122-2
Library of Congress Card Number 2002017441
Printed in the United States of America  1  2  3  4  5  6  7  8  9  0
Printed on acid-free paper
Library of Congress Cataloging-in-Publication Data
Nill, Kimball R.
Glossary of biotechnology terms / Kimball R. Nill.-- 3rd ed.
p.   cm.
ISBN 1-58716-122-2 
1. Biotechnology--Dictionaries. I. Title.
TP248.16 .F54 2002
660.6
′03--dc21
2002017441
© 2002 by CRC Press LLC

To my wife, Janet J. Nill.
© 2002 by CRC Press LLC

Preface
I began writing this book as a hobby, more than a decade ago, when it became obvious to me that
the various specialists working in the then-emerging field of biotechnology (e.g., geneticists,
chemists, molecular biologists, intellectual property attorneys, marketers, etc.) were occasionally
having difficulty simply understanding the terms utilized by colleagues in their respective fields.
Subsequently, a number of organizations with various motivations have raised some concerns
around the world about biotechnology. In my experience, the level of concern inevitably diminishes
when people understand the terms used to discuss a given topic. To this end, I have attempted to
write definitions in this book employing words that would enable the reader to conceptualize the
idea embodied in the term, without the necessity of holding advanced degrees in biochemistry or
molecular biology. In order to accomplish this, however, I had to make certain compromises between
scientific rigor and definitions based on analogy, with the inherent possibility of oversimplification.
Nonetheless, throughout the text, emphasis has been placed on explanation by analogy whenever
possible; I have found this method to be most effective for defining words, phrases, and terms to
diverse publics.
I offer this work in good faith, and in the hope that it will assist those individuals who seek to
gain some understanding of the terminology as it is currently used. However, the reader should be
aware that the field of biotechnology is rapidly expanding and evolving; new terms are entering
the nomenclature at a rapid pace. In fact, the meaning(s) of some of the newest terms will
undoubtedly be expanded or narrowed as the technology further develops. Although I have endeav-
ored to be as accurate as possible, this work is meant to provide a general introduction rather than
to be absolute and legally definitive. 
Kimball R. Nill
Technical Issues Director
American Soybean Association
St. Louis, Missouri
© 2002 by CRC Press LLC

Author
Kimball Nill, technical issues director at American Soybean Association (ASA), is responsible for
early detection of emerging technology-related issues that could impact U.S. soybean exports, and
for dealing proactively with those threats and/or opportunities.
The author grew up on a farm in North Dakota. He holds a bachelor of science degree in
chemistry from North Dakota State University, Fargo, and a masters degree in business adminis-
tration from the Wharton Business School in Philadelphia, PA. He has authored numerous papers
and articles on various aspects of marketing agricultural biotechnology products for U.S. and
European journals, and other publications. 
Prior to joining the ASA in 1996, Nill was international marketing manager for Moorman’s
Inc., an Illinois manufacturer of specialty livestock nutrition products. Before that, he spent 5 years
in positions supporting in-house venture capital and biotechnology research activities in a major
biotechnology company.
Professional affiliations include membership in the American Chemical Society, the Licensing
Executives Society, and the American Association for the Advancement of Science. 
© 2002 by CRC Press LLC

0-8493-XXXX-X/01/$0.00+$1.50
© 2001 by CRC Press LLC
A
Glossary of 
Biotechnology Terms
A
A-DNA A particular right-handed helical form
of DNA (possessing 11 base pairs per turn),
in which DNA molecules exist when they
are partially dehydrated. A-form DNA is
found in fibers at 75% relative humidity and
requires the presence of sodium, potassium,
or cesium as the counterion. Instead of lying
flat, the bases are tilted with regard to the
helical axis and there are more base pairs per
turn. The A-form is biologically interesting
because it is probably very close to the con-
formation adopted by DNA-RNA hybrids or
by RNA-RNA double-stranded regions. The
reason is that the presence of the 2
′2
hydroxyl group prevents RNA from lying in
the B-form. See also 
B
-
DNA
,
DNA
-
RNA HYBRID
,
DEOXYRIBONUCLEIC ACID
 (
DNA
),
BASE PAIR
 (
bp
).
A
␤PP See
AMYLOID
β
PROTEIN PRECURSOR
 (
A
β
PP
).
A
w
See
WATER ACTIVITY
 (
A
W
).
aAI-1 See
ALPHA AMYLASE INHIBITOR
-
1
.
ABC See
ASSOCIATION OF BIOTECHNOLOGY COM-
PANIES
 (
ABC
).
ABC Transporters A class of membrane
transporter proteins which “transfer” across
cell membranes: sugar molecules (i.e., used
by cells as “fuel”); inorganic ions (needed to
catalyze certain cellular processes); polypep-
tides (i.e., protein molecules); certain anti-
cancer drugs (thereby making it harder to halt
certain cancer tumors via use of pharmaceu-
ticals); certain antibiotics (thereby conferring
antibiotic resistance to some pathogenic bac-
teria). ABC transporter molecules are embed-
ded in the plasma membrane (i.e., surface
“skin”) of cells. See also 
CELL
,
PLASMA MEM-
BRANE
,
PROTEIN
,
CATALYST
,
ION
,
POLYPEPTIDE
(
protein
),
CANCER
,
CHEMOTHERAPY
,
ANTIBIOTIC
RESISTANCE
.
Abiogenesis Spontaneous generation. See also
BIOGENESIS
.
Abiotic Absence of living organisms. See also
ABIOTIC STRESSES
.
Abiotic Stresses The stress caused (e.g., to
crop plants) by nonliving, environmental fac-
tors such as cold, drought, flooding, salinity,
ozone, toxic-to-that-organism metals (e.g.,
aluminum, for plants), and ultraviolet-B light.
See also 
CITRATE SYNTHASE
 (
CSB
)
GENE
.
Abrin A toxin derived from the seed of the
rosary pea. See also 
RICIN
,
PHYTOCHEMICALS
,
TOXIN
.
Abscisic Acid A phytohormone (plant hor-
mone) utilized to control: the size of sto-
matal pores — i.e., the openings in leaves
through which plants exchange oxygen and
carbon dioxide (and water inadvertently)
with the atmosphere; abscision (e.g., shed-
ding of flowers, fruit, etc.); dormancy. See
also
PLANT HORMONE
,
GPA
1
.
Absolute Configuration The configuration of
four different substituent groups around an
asymmetric carbon atom, in relation to 
D
- and
L
-glyceraldehyde. See also 
DEXTROROTARY
(
D
)
ISOMER
,
LEVOROTARY
 (
L
)
ISOMER
.
Absorbance (A) A measure of the amount of
light absorbed by a substance suspended in
a matrix. The matrix may be gaseous, liquid,
or solid in nature. Most biologically active
© 2002 by CRC Press LLC

A
compounds (e.g., proteins) absorb light in
the ultraviolet (UV) or visible light portion
of the spectrum. Absorbance is used to quan-
titate (measure) the concentration of the sub-
stance in question (e.g., substance dissolved
in a liquid). See also 
OPTICAL DENSITY
  (
OD
),
SPECTROPHOTOMETER
.
Absorption From the Latin ab, away, and sor-
bere, to suck into. The taking-up of nutrients,
water, etc. by assimilation (e.g., transport of
the products of digestion from the intestinal
tract across the cell membranes that comprise
the gut, and into the blood). See also “
ADME
”
TESTS
,
DIGESTION
 (
WITHIN ORGANISMS
).
Abzymes Catalytic antibodies that are syn-
thetic constructs. They either stabilize the
transition state of a chemical reaction or bind
to a specific substrate, thereby increasing the
reaction rate of that chemical reaction. See
also
CATALYTIC ANTIBODY
,
TRANSITION STATE
,
SUBSTRATE
 (
CHEMICAL
).
Ac-CoA Abbreviation for Acetyl-coenzyme A.
Ac-CoA is a chemical synthesized in cell
mitochondria by combining the thiol
(molecular group) of coenzyme A with an
acetyl group (i.e., from breakdown/digestion
of fats, carbohydrates, or proteins). See also
COENZYME
,
COENZYME A
,
FATS
,
ACETYLCHOLINE
,
GLUCONEOGENESIS
,
ACETYL
-
C
o
A CARBOXYLASE
,
CHOLINESTERASE
,
CELL
,
MITOCHONDRIA
,
FATS
,
PROTEIN
.
Ac-P Acetylphosphate.
ACC Abbreviation/acronym for the compound
1-aminocyclopropane-1-carboxylic acid,
which is produced from S-adenosylmethion-
ine (SAM) in the fruit of certain plants.
When the “sam-k” gene is inserted into the
genome of those plants, the level of SAM is
greatly reduced in their fruit, which inhibits
(slows) ripening/softening of that fruit via a
reduction/slowdown in production of ethyl-
e n e   ( h o r m o n e   t h a t   c a u s e s   f r u i t   t o
ripen/soften). See also 
ACC SYNTHASE
,
ETHYL-
ENE
,
SAM
-
K GENE
,
GENETIC ENGINEERING
,
GENOME
,
PLANT HORMONE
.
ACC Synthase Aminocyclopropane carboxy-
lic acid synthase/deaminase; it is one of the
most critical enzymes in the metabolic path-
way that creates the hormone ethylene inside
fruit. Because ethylene causes certain fruit
(e.g., tomatoes) to ripen (soften), it is possible
to significantly delay the softening (i.e.,
spoilage) process by controlling creation of
ACC synthase via manipulation of the ACC
synthase gene. See also 
ACC
,
METABOLISM
,
ENZYME
,
METABOLITE
,
INTERMEDIARY METABO-
LISM
,
PATHWAY
,
PLANT HORMONE
,
POLYGALAC-
TURONASE
 (
PG
),
ETHYLENE
,
SAM
-
K GENE
.
ACCase See
ACETYL
-
C
o
A CARBOXYLASE
.
Acceptor Control The regulation of the rate
of respiration by the availability of ADP as
phosphate acceptor. See also 
RESPIRATION
,
ADENOSINE DIPHOSPHATE
 (
ADP
).
Acceptor Junction Site The junction between
the right 3
′ end of an intron and the left 5′
end of an exon. See also 
INTRON
,
EXON
.
Accession The addition of germ-plasm depos-
its to existing germ-plasm storage bands. See
also
AMERICAN TYPE CULTURE COLLECTION
(
ATCC
).
Acclimatization T h e   b i o l o g i c a l   p r o c e s s
whereby an organism adapts to a new envi-
ronment. For example, the body of a moun-
tain climber who has spent significant time
high on Mount Everest (e.g., 20,000 feet
above sea level) produces twice as many red
blood cells (to transport oxygen) as it does
at sea level. Often, this adaptation actually
occurs on a molecular level. One example is
when natural microorganisms adapt so that
they feed on, and degrade, toxic chemical
wastes; or change from using one sugar as
a fuel source to another. See also 
SUGAR
MOLECULES
,
CATABOLISM
,
RED BLOOD CELLS
,
COLD HARDENING
,
PHARMACOENVIROGENETICS
.
ACE Angiotensin-converting enzyme. A cru-
cial enzyme (within the human vascular sys-
tem) for catalyzing the formation of
angiotensin, a hormone that causes narrow-
ing/restriction of blood vessels, thus increas-
ing the body’s blood pressure as the blood
is squeezed through those narrowed blood
vessels. The action of ACE can be inhibited
by the pharmaceuticals known as ACE inhib-
itors. Research indicates that consumption
of whey protein can also result in inhibition
of ACE. See also 
ENZYME
,
HORMONE
,
ACE
INHIBITORS
.
ACE Inhibitors A family of chemically-simi-
lar pharmaceuticals utilized to lower blood
pressure in humans, by blocking formation
© 2002 by CRC Press LLC

A
of a hormone (angiotensin) that nar-
rows/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 car-
nitine). 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
A
c
-
C
o
A
.
Acetyl-CoA Acetyl-coenzyme A. See also
A
c
-
C
o
A
.
Acetyl-CoA Carboxylase An enzyme that
catalyzes the chemical reaction (i.e., conver-
sion of Ac-CoA to malonyl CoA via carbox-
ylation) 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 (manu-
factured) near the ends of axons (i.e., one
type of neuron). That synthesis is accom-
plished by the “transfer” of an acetyl group
(portion of molecule) from Ac-CoA to a cho-
line molecule (available in the body via con-
sumption of soybean lecithin or certain other
foods), in a chemical reaction catalyzed by
cholinesterase. Increased amounts of acetyl-
choline in the (human) brain has been shown
to reduce the symptoms of Alzheimer’s dis-
ease. See also 
NEUROTRANSMITTER
,
NEURON
,
CHOLINE
,
A
c
-
C
o
A
,
LECITHIN
,
ALZHEIMER
’
S DIS-
EASE
,
THYMUS
,
ENZYME
,
CHOLINESTERASE
.
Acetylcholinesterase An enzyme that hydro-
lyzes (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 acetyl-
choline 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 
ENZYME
,
HYDROLYSIS
,
NEUROTRANSMITTER
,
ACETYLCHOLINE
,
NEURON
.
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
(
C
4
H
4
O
4
).
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 accompa-
nied 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 forma-
tion of long-chain fatty acids. ACP is impor-
tant in that it is involved in every step of
fatty acid synthesis. See also 
FATTY ACID
,
ACYL
-
C
o
A
,
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
  (
T
4
CELLS
),
MACROPHAGE
,
TUMOR
NECROSIS FACTOR
 (
TNF
).
Acrylamide Gel See
POLYACRYLAMIDE GELS
.
ACTH [adrenocorticotropic hormone (corti-
cotropin)] 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 (cal-
ories) required to bring all the molecules in
one mole of a reacting substance to the tran-
sition 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.
© 2002 by CRC Press LLC

A
See also 
TRANSITION STATE
  (
IN A CHEMICAL
REACTION
),
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 trans-
forms the substrate molecule into the new
(chemical) product (entity). This site is usu-
ally located not on a protruding portion of
the enzyme, but rather in a cleft or depres-
sion. This establishes a controlled environ-
ment in which the chemical reaction may
occur. See also 
CATALYTIC SITE
,
AGONISTS
,
PHARMACOPHORE
,
SUBSTRATE
  (
CHEMICAL
),
ENZYME
,
ANTAGONISTS
.
Active Transport Cell-mediated, energy-
requiring translocation of a molecule across
a membrane in the direction of increasing
concentration (i.e., opposite of natural ten-
dency). 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 Syn-
genta AG, that can be inserted into plants via
genetic engineering techniques. Inserted into
the genome (DNA) of a plant, the gene con-
fers tolerance to herbicide(s) whose active
ingredient is protoporphyrinogen oxidase
inhibitor (thus, such herbicides are known as
PPO inhibitors). See also 
HERBICIDE
-
TOLER-
ANT CROP
,
GENE
,
GENETIC ENGINEERING
,
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
.