Biotechnology

Glycosinolates See
GLUCOSINOLATES
.
© 2002 by CRC Press LLC

G
Glycosylation (to glycosylate) Addition of oli-
gosaccharide units (e.g., to protein mole-
cules). The oligosaccharide units are linked
to either asparagine side chains by N-glyco-
sidic bonds or to serine and threonine side
chains by O-glycosidic bonds. See also
OLIGOSACCHARIDES
,
PROTEIN
,
GOLGI BODIES
,
PLANTIBODIES
™
,
BACULOVIRUS
.
Glycosyltransferases A class of enzymes
(transferases) that catalyze the addition
(chemical reaction) of specific sugars
(molecular groups) to oligosaccharides, gly-
coproteins, or glycosides. See also 
OLIGO-
SACCHARIDES
,
MONOSACCHARIDES
,
ENZYME
,
GLYCOPROTEIN
,
GLYCOSIDE
,
TRANSFERASES
.
Glyphosate An active ingredient in some her-
bicides, it kills plants (e.g., weeds) by inhib-
iting the crucial plant enzyme EPSP synthase.
See also 
ENZYME
,
EPSP SYNTHASE
,
CP
4
EPSPS
,
GLYPHOSATE OXIDASE
,
GLYPHOSATE
-
TRIMESIUM
,
GLYPHOSATE ISOPROPYLAMINE SALT
,
GA
21
.
Glyphosate Isopropylamine Salt One of sev-
eral forms of an active ingredient utilized in
some glyphosate-based herbicides. See also
GLYPHOSATE
,
EPSP SYNTHASE
,
CP
4
EPSPS
,
GLY-
PHOSATE OXIDASE
,
GLYPHOSATE
-
TRIMESIUM
.
Glyphosate Oxidase An enzyme that (via
catalysis) chemically breaks down glypho-
sate (i.e., the active ingredient in some her-
bicides). Glyphosate oxidase is produced in
nature by acclimated microorganisms. In
1988, Michael Heitkamp discovered a strain
of Pseudomonas bacteria which possessed a
gene (GO) that caused those particular
Pseudomonas bacteria to produce unusually
large amounts of glyphosate oxidase. That
GO gene can be incorporated into a variety
of crop plants (soybean, cotton, etc.) in order
to help enable those plants to survive post-
emergence applications of glyphosate-con-
taining herbicides. Additionally, a plant can
be genetically engineered to survive post-
emergence applications of glyphosate-con-
taining and/or sulfosate-containing herbi-
cides via insertion of gene (cassette) for
plant production of the enzyme CP4 EPSPS.
See also 
ENZYME
,
ACCLIMATIZATION
,
STRAIN
,
PSEUDOMONAS FLUORESCENS
,
GENE
,
GENETIC
ENGINEERING
,
BACTERIA
,
MICROORGANISM
,
SOYBEAN PLANT
,
EPSP SYNTHASE
,
CP
4
EPSPS
,
CASSETTE
,
GLYPHOSATE
,
SULFOSATE
,
GA
21
.
Glyphosate Oxidoreductase An enzyme nat-
urally produced in one strain of the micro-
organism  Ochrobactrum anthropi. That
enzyme (by catalysis) chemically breaks
down glyphosate (the active ingredient in
some herbicides). If a gene (called goxv247)
that codes for the production of glyphosate
oxidoreductase is inserted via genetic engi-
neering into crop plants, that would help
enable such plants to survive post-emergence
applications of glyphosate- and/or sulfosate-
containing herbicides. Additionally, a plant
can be genetically engineered to survive
post-emergence applications of glyphosate-
and/or sulfosate-containing herbicides via
insertion of gene (cassette) for plant produc-
tion of the enzyme CP4 EPSPS. See also
ENZYME
,
STRAIN
,
MICROORGANISM
,
GENE
,
GENETIC ENGINEERING
,
EPSP SYNTHASE
,
CP
4
EPSPS
,
CASSETTE
,
GLYPHOSATE
,
SULFOSATE
.
Glyphosate-Trimesium One of several forms
of active ingredient utilized in some glypho-
sate-based herbicides. See also 
GLYPHOSATE
,
EPSP SYNTHASE
,
CP
4
EPSPS
,
GLYPHOSATE OXI-
DASE
,
GLYPHOSATE ISOPROPYLAMINE SALT
,
GA
21
.
Gm Fad2-1 A (plant) gene that codes for delta
12 desaturase (
∆ 12). See also 
GENE
,
DELTA
12
DESATURASE
,
COSUPPRESSION
.
GMAC Acronym for the Genetic Manipula-
tion Advisory Committee of the country of
Australia, which advises the Australian gov-
ernment on matters pertaining to genetic
engineering (e.g., new rDNA product
approvals). The GMAC is analogous to Ger-
many’s ZKBS (Central Commission on Bio-
logical Safety), Brazil’s CTNBio (National
Technical Biosafety Commission), and the
Kenya Biosafety Council. See also 
GENE
TECHNOLOGY REGULATOR
 (
GTR
),
ZKBS
 (
CENTRAL
COMMISSION ON BIOLOGICAL SAFETY
),
RECOMBI-
NANT DNA ADVISORY COMMITTEE
 (
RAC
),
GENETIC
ENGINEERING
,
r
DNA
,
DEOXYRIBONUCLEIC ACID
(
DNA
),
CTNB
io
,
KENYA BIOSAFETY COUNCIL
,
GENE
TECHNOLOGY OFFICE
,
INTERIM OFFICE OF THE
GENE TECHNOLOGY REGULATOR
 (
IOGTR
).
GMO Genetically manipulated organism, or
genetically modified organism. See also
GENE
,
GENE SPLICING
,
GENETIC ENGINEERING
.
GMP See
GOOD MANUFACTURING PRACTICES
 (
GMP
).
GMP Guanylate See
G
-
PROTEINS
.
© 2002 by CRC Press LLC

G
GMPP See
GENETICALLY MODIFIED PEST PRO-
TECTED
 (
GMPP
)
PLANTS
.
GMS Genetically modified soya. See also 
GMO
,
SOYBEAN PLANT
.
GNE Group of National Experts on Safety in
Biotechnology. The group of people within
the OECD that developed OECD’s guide-
lines for nations to utilize in their safety
evaluations of foods derived from biotech-
nology. See also 
ORGANIZATION FOR ECONOMIC
COOPERATION AND DEVELOPMENT
  (
OECD
),
BIO-
TECHNOLOGY
,
GENETIC ENGINEERING
.
GO Gene See
GLYPHOSATE OXIDASE
.
Golden Rice A biotechnology-derived rice
(Oryza sativa) created in the 1990s by Ingo
Potrykus and Peter Beyer, which contains
large amounts of beta carotene (precursor of
vitamin A) in its seeds. The human body
converts beta carotene into vitamin A. Pot-
rykus and Beyer utilized Agrobacterium
tumefaciens bacteria to genetically engineer
rice plants (by inserting the following genes
from daffodil and from the bacterium
Erwinia uredovora:
1. Phytoene synthase — from daffodil
(narcissus) which converts geranylger-
anyl-diphosphate into phytoene.
2. “CRTL” gene — from Erwinia ure-
dovora, which codes for phytoene
desaturase, which causes the rice plant
to convert phytoene (a “light harvest-
ing” carotenoid involved in photosyn-
thesis) into lycopene (a carotenoid
which is then utilized by the rice plant
in the production of beta carotene).
3. Lycopene beta-cyclase — from daffo-
dil, which converts lycopene into beta
carotene.
The United Nations (UNICEF) estimates
that 1 to 2 million deaths of children aged
1–4 years old could be prevented annually
around the world, if they received a little
more vitamin A daily in their diet (e.g., via
such a rice). Some of the diseases caused by
lack of vitamin A include: childhood blind-
ness (estimated to afflict 350,000–500,000
children per year); coronary heart disease;
certain cancers (cancer of the lungs, prostate,
etc.); macular degeneration, a leading cause
of blindness in older people; and various
childhood diseases which result in death
(due to a weakened immune system).
Research indicates that, when commer-
cialized in the future, “golden rice” will also
contribute more iron (bioavailable) to the
human diet. That will be due to inserted
genes for ferritin (an iron-rich storage pro-
tein) and phytase. Because iron deficiency
anemia (IDA) is a major cause of maternal
and childhood illnesses in developing coun-
tries, such a reduction in IDA via consumption
of this rice could confer major health benefits
to those countries’ populations. See also 
BIO-
TECHNOLOGY
,
BETA CAROTENE
,
VITAMIN
,
PHYTO-
CHEMICALS
,
NUTRACEUTICALS
,
CAROTENOIDS
,
GENE
,
GENETIC ENGINEERING
,
BACTERIA
,
AGRO-
BACTERIUM TUMEFACIENS
,
PHOTOSYNTHESIS
,
LYCOPENE
,
CORONARY HEART DISEASE
  (
CHD
),
IRON DEFICIENCY ANEMIA
  (
IDA
),
PROTEIN
,
PHYTASE
,
PATHWAY
,
METABOLIC PATHWAY
,
MET-
ABOLIC ENGINEERING
.
GoldenRice
TM
A registered trademark now
owned by the company Syngenta AG. See
also
GOLDEN RICE
.
Golgi Apparatus See
GOLGI BODIES
.
Golgi Bodies (also known as Golgi complexes)
First described by Camillo Golgi in 1898,
these are the primary “sorting centers” of
cells, and the mechanism for glycosylation
of (i.e., adding oligosaccharide and polysac-
charide branches onto) proteins, before those
proteins are then transported by transfer ves-
icles to lysosomes, secretory vesicles, or the
plasma membrane. In plant cells, Golgi com-
plexes are where complex polysaccharides
are “sorted” and assembled in preparation
for making the cell wall (located just outside
the cell’s plasma membrane). Visually, a
Golgi complex is a stack of flattened mem-
branous sacs (usually 6 sacs in mammal cells
and 20 sacs in plant cells). See also 
GLYCO-
SYLATION
,
CELL
,
OLIGOSACCHARIDES
,
POLYSAC-
CHARIDES
,
PROTEIN
,
LYSOSOME
,
VESICLES
,
PLASMA
MEMBRANE
.
Golgi Complexes See
GOLGI BODIES
.
Good Laboratory Practice for Nonclinical
Studies (GLPNC) The Good Laboratory
Practice (GLP) that is required by the U.S.
Food and Drug Administration (FDA) for
studies of the safety and toxicological effects
© 2002 by CRC Press LLC

G
of new drugs for livestock. See also 
GOOD
LABORATORY PRACTICES
 (
GLP
),
NADA
.
Good Laboratory Practices (GLP) A set of
rules and regulations issued by the Food and
Drug Administration (FDA) that establishes
broad methodological guidelines for proce-
dures and record keeping. They are to be
followed in laboratories involved in the test-
ing and/or preparation of pharmaceuticals.
GLPs also apply to the Environmental Pro-
tection Agency (EPA) (e.g., in toxicity test-
ing of new herbicides).
Good Manufacturing Practices (GMP) T h e
set of general methodologies, practices, and
procedures mandated by the Food and Drug
Administration (FDA) which is to be fol-
lowed in the testing and manufacture of
pharmaceuticals. The purpose of GMPs is
essentially to provide for record keeping,
and in a wider context to protect the public.
GMP guidelines exist instead of specific reg-
ulations due to the newness of the technol-
ogy, and may later be superceded (modified)
due to further advances in technology and
understanding. See also 
c
GMP
.
Gossypol A yellow pigment produced in
glands and seeds of the cotton plant (Gos-
sypium spp.), and some other plants. When
consumed by monogastric animals (e.g.,
swine, poultry, etc.), gossypol is somewhat
toxic to those animals. See also 
COTTON
,
PHYTOTOXIN
.
GP120 Protein An adhesion molecule (glyco-
protein) on the envelope (surface membrane)
of HIV (i.e., AIDS-causing) viruses that
directly interacts with the CD4 protein on
helper T cells; enabling the HIV viruses to
bind to and infect helper T cells. In 1994, a
group at America’s Scripps Research Insti-
tute led by Dennis Burton and Carlos Barbas
III announced that they had generated a
recombinant human antibody to the GP120
protein; which neutralized more than 75%
of HIV isolates against which it was tested.
This advance holds the potential to someday
lead to a vaccine against AIDS. See also
MONOCLONAL ANTIBODIES
 (
MA
b
),
HUMAN IMMU-
NODEFICIENCY VIRUS TYPE
1
  (
HIV-
1
),
HUMAN
IMMUNODEFICIENCY VIRUS TYPE
2
  (
HIV-
2
),
ACQUIRED IMMUNE DEFICIENCY SYNDROME
 (
AIDS
),
SOLUBLE CD
4
,
CD
4
PROTEIN
,
HELPER T CELLS
(
T
4
CELLS
),
CD
44
PROTEIN
,
ADHESION MOLECULE
,
CONSERVED
,
GLYCOPROTEIN
,
SELECTINS
,
LECTINS
,
PROTEIN
.
GPA1 A gene, found in most plants, responsi-
ble for controlling water retention and cell
division in those plants. The GPA1 gene
codes for a G-protein, which transmits/reg-
ulates signals (light, temperature, phytohor-
mones, nutrients, etc.) controlling the plant’s
development.
During 2001, Alan Jones and colleagues
discovered that “knocking out” (silencing)
the GPA1 gene caused the (then-resultant)
G-protein to be insensitive to abscisic acid.
Because abscisic acid is a phytohormone
(plant hormone) utilized by plants to control
the size of stomatal pores [i.e., the openings
in leaves through which plants exchange
oxygen and carbon dioxide (and also water
inadvertently) with the atmosphere], the
“knocked-out GPA1” plants wilted due to
uncontrolled water loss to the atmosphere.
See also 
GENE
,
CELL
,
MITOSIS
,
G
-
PROTEINS
,
PLANT HORMONE
,
ABSCISIC ACID
,
KNOCKOUT
(
GENE
).
GPCRs Acronym for G-Protein-Coupled Recep-
tors. See also 
G
-
PROTEIN
-
COUPLED RECEPTORS
.
Graft-Versus-Host Disease (GVHD) The
rejection of transplanted organs by the recip-
ient’s immune system. Also known as hyper-
acute rejection. It is caused by the attack of
the recipient’s T lymphocytes (T cells, a cer-
tain class of white blood cells) on the trans-
planted organ. The recipient’s T cells are
able to distinguish between self and foreign
cells, and are hence able to recognize the
foreign (nonself) cells of the transplanted
organ. They then, naturally, try to destroy the
“foreign invaders” in the body. This consti-
tutes rejection of the transplanted organ.
From this it should be understood that there is
nothing wrong with the body, but that it is
behaving exactly as it should. See also 
CELLU-
LAR IMMUNE RESPONSE
,
HUMORAL IMMUNITY
,
XENOGENEIC ORGANS
,
FIBROBLASTS
,
CYCLOSPORIN
.
Gram Molecular Weight T h e   w e i g h t   i n
grams of a compound that is numerically
equal to its molecular weight; the weight of
one mole (6.02 
× 1023 molecules). See also
MOLECULAR WEIGHT
,
MOLE
.
© 2002 by CRC Press LLC

G
Gram Stain Devised by Hans Christian
Joachim Gram in 1884, this is a test that
illuminates the composition/makeup of the
physical structure of the cell wall of bacteria
being tested. It is utilized to judge the effec-
tiveness of a given chemical compound (e.g.,
an antibiotic) against bacteria types. The test
consists of a differential staining procedure,
which allows most bacteria to be visually
separated into two groups, known as Gram-
Positive (G+) and Gram-Negative (G-).
An antibiotic is defined in terms of the
group of (pathogenic) bacteria that it is
effective against, which is known as that
antibiotic’s “spectrum of activity.” An anti-
biotic is said to have a spectrum of activity
against gram-positive bacteria, gram-nega-
tive bacteria, or the bacteria of both groups.
An antibiotic that is effective against both
groups of bacteria is termed “broad spec-
trum” or “wide spectrum.” See also 
BACTE-
RIA
,
GRAM
-
POSITIVE
 (
G
+
),
GRAM
-
NEGATIVE
 (
G-
),
PATHOGENIC
,
CELL
,
ANTIBIOTIC
.
Gram-Negative (G-) Pertaining to one of the
most important ways of classifying bacteria
by means of the differences in the way they
stain. The set of bacteria that are not able to
be stained (blue) when treated with the gram
staining procedure. Gram negativity (and
gram positivity) is conferred not by the
chemical constituents of the bacteria, but
rather by the physical structure of the bac-
teria cell wall. The staining procedure
involves the staining of all cells in a sample
with a blue dye. Gram-negative bacteria
have a very thin peptidoglycan cell wall
(capsule). Hence, the washing procedure,
which is an integral part of the overall stain-
ing procedure, washes out the blue dye
(known as crystal violet). This leaves the
gram-negative bacteria colorless. The cells
are then stained with a red acidic counter-
stain (dye) such as acid fuchsin or safranine.
After treatment with counterstain, the gram-
negative cells are red and the gram-positive
cells are blue. See also 
GRAM
-
POSITIVE
  (
G
+
),
BACTERIA
,
CELL
,
GRAM STAIN
.
Gram-Positive (G+) Pertaining to bacteria,
holding the color of the primary stain (blue)
when treated with Gram’s stain (a commercial
staining agent), or Gentian violet solution. In
contrast to the gram-negative bacteria, the
gram-positive bacteria possess a much
thicker peptidoglycan cell wall (capsule).
Because of this, the blue crystal violet dye
(with which the bacteria were stained) does
not wash out of the cell and the bacteria
appear blue under the microscope. See also
GRAM
-
NEGATIVE
  (
G
-),
BACTERIA
,
CELL
,
GRAM
STAIN
,
CAPSULE
.
Granulation Tissue A mixture of proteins and
cells produced by the fibroblast growth that
results from a wound. See also 
FIBROBLASTS
,
PROTEIN
.
Granulocidin A protein produced by white
blood cells, which has demonstrated (in the
laboratory) an ability to kill a broad spectrum
of pathogens. See also 
PATHOGEN
,
PROTEIN
.
Granulocyte Colony Stimulating Factor
(G-CSF) A colony stimulating factor (CSF;
a protein) that stimulates production of gran-
ulocytes, particularly neutrophils. See also
COLONY STIMULATING FACTORS
,
GRANULOCYTES
,
NEUTROPHILS
.
Granulocyte-Macrophage Colony Stimulating
Factor (GM-CSF) (or Granulocyte-Mono-
cyte Colony Stimulating Factor) A colony
stimulating factor (CSF; a protein) that stim-
ulates production of granulocytes/macroph-
ages/monocytes. See also 
COLONY STIMULATING
FACTORS
 (
CSF
s
),
MACROPHAGE
,
MONOCYTES
.
Granulocytes (polymorphonuclear granulo-
cytes) Phagocytic (scavenging, ingesting)
cells that are part of the immune system.
When their cell nucleus is segmented into
lobes and they have granule-like inclusions
within their cytoplasm (the neutrophils, eosi-
nophils, and basophils), they are collectively
known as polymorphonuclear granulocytes.
See also 
PHAGOCYTE
.
GRAS List A list of food additives/ingredients
considered to be Generally Recognized as
Safe, by the U.S. Food and Drug Adminis-
tration (FDA). This list of additives is judged
to be safe by a panel of FDA pharmacologists
and toxicologists, who base their judgment
upon data that is available for each ingredi-
ent. In practice, those additives for which
extensive experience of common use in foods
(without known ill effects) has been accumu-
lated over time (e.g., common table salt) are
often approved by the FDA due more to the
© 2002 by CRC Press LLC

G
“common use factor” than to any toxicology
data, per se. See also 
FOOD AND DRUG ADMIN-
ISTRATION
 (
FDA
),
DELANEY CLAUSE
,
PHARMACOL-
OGY
,
CANOLA
.
Grass Pea See
GLUCOSINOLATES
.
Green Fluorescent Protein A protein that is
naturally present within the jellyfish Aequo-
rea victoria. Green fluorescent protein
(GFP) is utilized by scientists to “mark” cer-
tain endpoints in experiments (at which
point the green light signals that endpoint
was reached). See also 
FLUORESCENCE
,
PROTEIN
,
GENE EXPRESSION MARKERS
.
GRF See
GROWTH HORMONE RELEASING FACTOR
.
GRH See
GROWTH HORMONE RELEASING FACTOR
.
Group of National Experts on Safety in Bio-
technology See
GNE
.
Growth (microbial) An increase in the num-
ber of cells. See also 
GENERATION TIME
.
Growth Curve The change in the number of
cells in a growing culture as a function of
time. See also 
GENERATION TIME
.
Growth Factor A specific substance that must
be present in the organism’s tissues (when
in vivo) or growth medium (when in vitro)
in order for the growth-factor-specific cells
to grow/multiply. See also 
FIBROBLAST
GROWTH FACTOR
 (
FGF
),
NERVE GROWTH FACTOR
(
NGF
),
EPIDERMAL GROWTH FACTOR
 (
EGF
),
VAS-
CULAR ENDOTHELIAL GROWTH FACTOR
  (
VEGF
),
ANGIOGENIC GROWTH FACTORS
,
ANGIOGENIN
,
BONE MORPHOGENETIC PROTEINS
 (
BMP
).