Biotechnology

S
some psychiatric disorders. In the case of
chronic, intractable pain (hypersensitivity),
approximately 1% of the nerve cells in the
human spine processes substance P (thereby
“transmitting” its pain message via signal
transduction). In 1997, Patrick Mantyh
showed that killing those (1%) cells relieved
chronic pain hypersensitivity without
impairing sense of touch or normal (benefi-
cial) pain sensation, in humans. See also
TACHYKININS
,
PROTEIN
,
POLYPEPTIDE
 (
PROTEIN
),
SIGNAL TRANSDUCTION
,
SIGNALING
,
PEPTIDE
,
NEUROTRANSMITTER
.
Substantial Equivalence See
CANOLA
,
ORGANI-
ZATION FOR ECONOMIC COOPERATION AND
DEVELOPMENT
 (
OECD
).
Substantially Equivalent See
S U B S T A N T I A L
EQUIVALENCE
.
Substrate (chemical) The substance acted
upon by an enzyme. For example, the
enzyme amylase catalyzes the breakdown of
starch molecules into glucose polysaccha-
ride molecules; starch is the substrate (of the
enzyme amylase). See also 
ENZYME
,
AMYLASE
,
CATALYST
,
SUBSTRATE
 (
STRUCTURAL
).
Substrate (in chromatography) The (usually
solid or gel) substance that attracts and non-
covalently binds (interacts) with one or more
of the molecules in a solution that is passed
over that substrate (e.g., in a chromatogra-
phy column). This preferential binding
(interaction with the substrate) enables one
or more of the solution’s molecular ingredi-
ents to be separated from the other(s). See
also
CHROMATOGRAPHY
.
Substrate (structural) The substance (sup-
port) to which the agent of interest (a mol-
ecule) is attached. For example, some
catalyst molecules are chemically attached
to nonreactive solids to preserve the catalyst
from being flushed away when the chemical
substrate (the molecule to be converted by
the catalyst) is washed by the catalyst immo-
bilized on the structural substrate. See also
SUBSTRATE
  (
CHEMICAL
),
CATALYST
,
HYBRIDIZA-
TION SURFACES
.
Sudden Death Syndrome A plant disease
caused by the Fusarium solani fungus, that
sometimes afflicts soybean plants. See also
SOYBEAN PLANT
,
SOYBEAN CYST NEMATODES
(
SCN
).
Sugar Molecules S e e
O L I G O S A C C H A R I D E S
,
POLYSACCHARIDES
,
MONOSACCHARIDES
,
CARBO-
HYDRATES
,
ALDOSE
,
GLYCOBIOLOGY
,
PYRANOSE
,
GLUCOSE
 (
GL
c
),
FURANOSE
,
GLYCOPROTEIN
.
Suicide Genes See
GENE
,
p53
GENE
,
APOPTOSIS
.
Sulfate Reducing Bacterium See
SRB
 (
SULFATE
REDUCING BACTERIUM
).
Sulforaphane A compound naturally pro-
duced within cruciferous plants such as
broccoli and cabbage. Research indicates
that human consumption of significant
amounts of sulforaphane helps lower the risk
of several cancers. See also 
NUTRACEUTICALS
,
PHYTOCHEMICALS
,
CANCER
.
Sulfosate An active ingredient in some herbi-
cides, it kills plants (e.g., weeds) by inhibit-
ing the crucial plant enzyme EPSP Synthase.
Chemically, sulfosate is a trimethylsulfo-
nium salt of the same organic acid as gly-
phosate, so sulfoste can be applied over
crops (e.g., soybeans) that have been genet-
ically engineered to be tolerant to glypho-
sate-based herbicides. See also 
ENZYME
,
EPSP
SYNTHASE
,
CP
4
EPSPS
,
GLYPHOSATE
,
ACID
,
SOY-
BEAN PLANT
,
HERBICIDE
-
TOLERANT CROP
,
GENETIC ENGINEERING
.
Superantigens Certain types of antigens that
activate a large proportion of an organism’s
immune system T cells. These superanti-
gens, which thus overactivate the organism’s
immune system, are thought to be responsi-
ble for some autoimmune diseases (in which
T cells attack and destroy the organism’s
own, healthy tissues). See also 
ANTIGEN
,
T CELLS
,
AUTOIMMUNE DISEASE
.
Supercoiling Also known as superhelicity. The
coiling of a closed duplex DNA (deoxyribo-
nucleic acid molecule) in space so that it
crosses over its own axis. See also 
DEOXY-
RIBONUCLEIC ACID
 (
DNA
),
HELIX
,
DUPLEX
,
DOUBLE
HELIX
,
POSITIVE SUPERCOILING
.
Supercritical Carbon Dioxide A solvent that,
when combined with water and an appropri-
ate surfactant (e.g., fluoroethers), forms a
solvent system that can effectively dissolve
large biological molecules without causing
those molecules to lose biological activity.
Carbon dioxide is a gas at normal (atmo-
spheric) pressure and ambient temperature,
but in its supercritical state — temperature
above 31.3°C (88°F) and pressure greater
© 2002 by CRC Press LLC

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than 72.9 atmospheres — carbon dioxide
becomes a dense (sort of) liquid. Some cof-
fee processors have used supercritical car-
bon dioxide as a solvent to remove caffeine
from coffee.
In 1995, Keith Johnston added the surfac-
tant ammonium carboxylate perfluoropoly-
ether to a supercritical carbon dioxide
system containing water and proved that the
large biological molecule bovine serum
albumin dissolved inside the micelles that
form via water droplet surrounded by fluo-
roether molecules. Subsequent to that, Eric
Beckman proved that the protease subtilisin
Carlsberg can be extracted from crude
(impure) cell broth because that protease
preferentially dissolves in a supercritical car-
bon dioxide/water system containing fluoro-
ether amphiphiles as surfactants. See also
BIOLOGICAL ACTIVITY
,
SURFACTANT
,
MICELLE
,
REVERSE MICELLE
  (
RM
),
BROTH
,
PROTEASE
,
SUPERCRITICAL FLUID
,
ALBUMIN
.
Supercritical Fluid Refers to a material that
has been heated to a temperature above its
(normal atmospheric pressure) boiling point,
but which is kept in a state that resembles a
liquid via the application of high pressure.
Less commonly, refers to a liquid that has
been cooled to a temperature below its nor-
mal freezing point, but which is kept in a
liquid state by various means. For example,
water will remain “liquid” up to a tempera-
ture of 375°C (617°F) if it is placed under
enough pressure. Ammonia will remain “liq-
uid” up to a temperature of 133°C (271°F)
if it is placed under enough pressure, despite
the fact that ammonia normally becomes a
gas (at standard atmospheric pressure)
whenever the temperature is higher than
–33.35°C (–30°F).
One predatory mite (Alaskozetes antarcti-
cus) living in Antarctica is able to survive
subfreezing temperatures by preventing ice
crystals from forming (i.e., supercritical
water) inside its body, even when the envi-
ronmental temperature is below the freezing
point (i.e., supercritical). Most supercritical
fluids have unique physical properties (e.g.,
they are often better solvents than their true
liquid forms). Some supercritical fluids (e.g.,
supercritical carbon dioxide) can be used to
extract biological molecules (e.g., chloro-
phyll) from mixtures (e.g., ground-up plant
leaves). After the biological molecule has
dissolved out of the mixture, the biological
molecule is recovered by releasing pressure
so the carbon dioxide returns to gaseous
form, and drifts away. See also 
SUPERCRITICAL
CARBON DIOXIDE
.
Superoxide Dismutase (SOD) S e e
H U M A N
SUPEROXIDE DISMUTASE
 (
h
SOD
).
Suppressor Gene A gene that can reverse the
effect of a specific type of mutation in other
genes, such as a premature termination
sequence. See also 
GENE
,
TRANSWITCH
®
.
Suppressor Mutation A mutation that totally
or partially restores a function lost by a pri-
mary mutation. It is located at a site in the
gene different from the site of the primary
mutation. See also 
GENE
.
Suppressor T Cells Those T cells (thymus-
derived lymphocytes) that are triggered
(after other types of T cells and other
immune system cells have successfully
fought off an infection) to slow down grad-
ually and halt the body’s immune response
(to the now-conquered pathogen). Discov-
ered by Tomio Tada in 1971, suppressor
T cells inhibit B cell activity. Failure to halt
the immune response in time could lead to
harm to the body by its own immune system.
The B and T lymphocytes are indistinguish-
able in size and general morphology. Only
the existence or nonexistence of certain pro-
teins on their cell surfaces distinguishes the
two classes of lymphocytes. See also 
CELLU-
LAR IMMUNE RESPONSE
,
PATHOGEN
,
B LYMPHO-
CYTES
,
T CELLS
,
AUTOIMMUNE DISEASE
.
Supramolecular Assembly Refers to a very
large molecular structure. See also 
SELF
-
ASSEMBLY
  (
OF A LARGE MOLECULAR STRUC-
TURE
).
Surfactant Acronym for surface active agent.
Amphipathic molecules (i.e., molecules that
contain both a polar and nonpolar domain)
which, due to their unique properties, posi-
tion themselves at interfacial regions (sur-
faces) such as an oil/water interface. When
surfactants are dissolved above a certain crit-
ical concentration in either water or nonpolar
solvents, they may form micelles or reverse
micelles, respectively. Surfactants are
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commonly used to solubilize cell membrane
components and other hard-to-solubilize
molecules. See also 
AMPHIPATHIC MOLECULES
,
AMPHIPHILIC MOLECULES
,
MICELLE
,
REVERSE
MICELLE
 (
RM
),
SDS
,
ADJUVANT
 (
TO A HERBICIDE
).
Sustainable Development D e fi n e d   i n   t h e
1987 United Nations report “our common
future” to be development (e.g., economic
development) that meets the needs of the
present without compromising the ability of
future generations to meet their own needs.
See also 
CONSERVATION TILLAGE
,
GLOMALIN
,
NO
-
TILLAGE CROP PRODUCTION
,
LOW
-
TILLAGE
CROP PRODUCTION
,
EARTHWORMS
.
Switch Proteins Refers to certain protein mol-
ecules that signal a plant when environmen-
tal conditions are so dry (or cold, etc.) that
the plant needs to protect itself (via extreme
measures) to survive. See also 
TREHALOSE
,
PROTEIN
,
SIGNALING
,
TRANSCRIPTION FACTORS
,
CBF
1
,
SEQUENCE
  (
OF A DNA MOLECULE
),
REGU-
LATORY SEQUENCE
.
Switching (e.g., on/off) of Genes See
G E N E
,
GENETIC CODE
,
CODING SEQUENCE
,
DEOXYRIBO-
NUCLEIC ACID
 (
DNA
),
SEQUENCE
 (
OF A DNA MOL-
ECULE
),
REGULATORY SEQUENCE
,
TRANSCRIPTION
FACTORS
,
CBF
1
,
COLD HARDENING
,
CESSATION
CASSETTE
.
Syk Protein See
MAST CELLS
.
Symbiotic Refers to the mutually beneficial
living together of organisms, in an intimate
association or union. For example, lichen are
a life form consisting of algae and a fungus
growing together as a unit on a solid surface
(e.g., a tree trunk or a rock). Each helps the
other to survive and grow. See also 
ALGAE
,
FUNGUS
,
RHIZOBIUM
  (
BACTERIA
),
PHARMACOEN-
VIROGENETICS
,
ANTIBIOSIS
.
Synthase See
ACC SYNTHASE
,
EPSP SYNTHASE
,
ENZYME
,
CP
4
EPSPS
,
CITRATE SYNTHASE
  (
CS
b
)
GENE
,
GLUTAMINE SYNTHETASE
,
ALS GENE
.
Synthesizing (of DNA molecules) The build-
ing (i.e., polymerization manufacture) of a
known sequence of nucleotides into a chain
called an oligonucleotide (of which genes
are made) or DNA (deoxyribonucleic acid).
Invented by Har Goribind Khorana and his
colleagues at the University of Wisconsin,
Madison, in 1968, this process enables sci-
entists to create genes or gene fragments for
use in research. In 1973, Robert Bruce
Merrifield developed a means to partially
automate the oligonucleotide assembly pro-
cess. This led to automated machines that
can now rapidly manufacture a gene frag-
ment, gene, or DNA probe. See also 
GENE
MACHINE
,
NUCLEOTIDE
,
OLIGOMER
,
OLIGONUCLE-
OTIDE
,
SYNTHESIZING
  (
OF PROTEINS
),
DEOXY-
R I B O N U C L E I C
A C I D
  (
D N A
),
D N A
P R O B E
,
SYNTHESIZING
 (
OF OLIGOSACCHARIDES
).
Synthesizing (of oligosaccharides) Chemical
synthesis (manufacture) of a known oli-
gosaccharide (structure). For example, a
synthesis of a defined-sequence oligosaccha-
ride (molecular) “branch” at a specific site
on a glycoprotein in order to “cover up” an
antigenic site on that glycoprotein molecule
(e.g., so the glycoprotein can be used as a
pharmaceutical). See also 
OLIGOSACCHARIDES
,
GLYCOPROTEIN
,
ANTIGEN
,
ANTIGENIC DETERMI-
NANT
,
RESTRICTION ENDOGLYCOSIDASES
.
Synthesizing (of proteins) Chemical synthe-
sis (manufacture) of a known protein mole-
cule. Devised based upon the solid phase
synthesis methodology developed by Robert
Bruce Merrifield in 1963, the desired pro-
teins are assembled by repetitive coupling of
the constituent amino acids to a growing
polypeptide backbone, which itself is
attached to a polymeric support (substrate).
This procedure has been automated, so it is
now possible to make proteins via automated
synthesizers. See also 
PROTEIN
,
POLYPEPTIDE
(
PROTEIN
),
AMINO ACID
,
SUBSTRATE
  (
STRUC-
TURAL
),
COMBINATORIAL CHEMISTRY
,
SYNTHE-
SIZING
 (
OF DNA MOLECULES
).
Synthetase See
SYNTHASE
.
Systematic Activated Resistance See
SYSTEMIC
ACQUIRED RESISTANCE
 (
SAR
).
Systematics An extension of taxonomy, it is the
scientific classification of living organisms.
Systemic Acquired Resistance (SAR) D i s -
covered in 1992 (applicable to harpin-
induced SAR) and in 1996 by J.A. Ryals,
U.H. Neuenschwander, M.G. Willits, A.
Molina, H.-Y. Steiner, and M.D. Hunt, SAR
is a sort of “immune (cascade) response” by
a plant, against infection (by bacteria, fun-
gus, etc.). One example of this is the pro-
duction of stress proteins or pathogenesis-
related proteins when certain plants are
attacked by certain pathogens. Via such SAR
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response triggered by low-level fungal or
viral infection, many plants successfully
resist fungal/bacterial/viral attacks.
In 1998, the U.S. Environmental Protec-
tion Agency (EPA) approved one herbicide
(COBRAR owned by Valent Corp.), whose
active ingredient is the chemical lactofin, to
be applied to soybean plants “at or near
bloom stage” in order to trigger SAR against
white mold disease. In 2000, the U.S. EPA
approved harpin protein to be applied to
some crops in order to trigger SAR against
certain plant diseases. See also 
PATHOGENESIS
RELATED PROTEINS
,
PHYTOALEXINS
,
R GENES
,
ISOFLAVONES
,
SOYBEAN PLANT
,
FUNGUS
,
IMMUNE
RESPONSE
,
VIRUS
,
PATHOGEN
,
STRESS PROTEINS
,
SALICYLIC ACID
  (
SA
),
JASMONIC ACID
,
HARPIN
,
CASCADE
,
WHITE MOLD DISEASE
.
Systemic Inflammatory Response Syndrome
See
SEPSIS
.
© 2002 by CRC Press LLC

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T
T Cell Growth Factor (TCGF) Also known
as Interleukin-2. See also 
INTERLEUKIN
-
2
 (
IL-
2
).
T Cell Modulating Peptide (TCMP) A short
protein chain that is thought to restrain cer-
tain types of T cells from attacking an
(arthritis) afflicted patient’s tissues (mainly
cartilage). Arthritis is caused by the suf-
ferer’s own immune system attacking the
body’s cartilage tissues. See also 
CYTOTOXIC
T CELLS
,
HELPER T CELLS
  (
T
4
CELLS
),
LYMPHO-
CYTE
,
SUPPRESSOR T CELLS
,
T CELL RECEPTORS
,
AUTOIMMUNE DISEASE
,
TUMOR NECROSIS FACTOR
(
TNF
).
T Cell Receptors Antibody-like transmem-
brane (i.e., across the cell’s surface mem-
brane) proteins located on the surface of
T cells. These trigger the (cellular) immune
response that is mounted by T cells when
these receptors bind to antigens (foreign
pieces of antigenic protein) that have been
“presented” to these receptors by an MHC
protein which itself is located on the surface
of phagocytic (i.e., scavenging, pathogen-
ingesting) B lymphocyte. Antibodies in the
blood recognize native antigen macromole-
cules (large molecules), whereas T cell
receptors recognize fragments derived from
those antigen macromolecules (upon presen-
tation at the surface of B lymphocytes fol-
lowing ingestion and digestion by the
B lymphocytes). See also 
ANTIBODY
,
ANTIGEN
,
MAJOR HISTOCOMPATIBILITY COMPLEX
  (
MHC
),
PROTEIN
,
T CELLS
,
CELLULAR IMMUNE RESPONSE
,
PHAGOCYTE
,
B LYMPHOCYTES
,
CYTOTOXIC T CELLS
,
HELPER T CELLS
,
SUPPRESSOR T CELLS
.
T Cells A class of (thymus-derived) lympho-
cytes that include helper T cells (also
known as T helper cells or T
H
 cells), sup-
pressor T cells, and cytotoxic T cells (also
known as killer cells or CTL for cytotoxic
T lymphocyte). These cells mediate (i.e.,
control/direct) the cellular response of the
human immune system in very complex
ways. T cells are involved in the activation
of B cells. See also 
CELLULAR IMMUNE
RESPONSE
,
CYTOTOXIC T CELLS
,
HELPER T CELLS
(
T
4
CELLS
),
LYMPHOCYTE
,
SUPPRESSOR T CELLS
,
T CELL RECEPTORS
,
T CELL MODULATING PEPTIDE
(
TCMP
),
ALLERGIES
  (
FOODBORNE
),
DENDRITIC
CELLS
,
LEUKOTRIENES
.
T Lymphocytes See
T CELLS
,
LYMPHOCYTE
,
LYMPHOKINES
,
THYMUS
.
T-DNA See
T
i
PLASMID
.
t-IND Treatment Investigational New Drug
Application to the U.S. Food and Drug
Administration (FDA). See also “
TREATMENT
”
IND REGULATIONS
.
t-IND Treatment Investigational New Drug
Application to the U.S. Food and Drug
Administration (FDA). See also “
TREATMENT
”
IND REGULATIONS
.
T3 See
SAM
-
K GENE
.
T4 Cells See
HELPER T CELLS
 (
T
4
CELLS
).
Tachykinins A class of neuropeptides (i.e.,
peptides produced by cells of the nervous
system; neurons) that includes neurokinin A,
neurokinin B, eledoisin, physalaemin, kassi-
nin, substance P, and substance K. Some of
these neuropeptides (e.g., Substance P) are
picked up by mast cells, lymphocytes, and/or
monocytes; and cause those three types of
immune system cells to release certain lym-
phokines (e.g., tumor necrosis factor, inter-
leukin-1 etc.), thus activating the immune
system. See also 
MAST CELLS
,
LYMPHOCYTE
,
MONOCYTES
,
TUMOR NECROSIS FACTOR
  (
TNF
),
INTERLEUKIN
-
1
 (
IL-
1
).
TAG See
TRIACYLGLYCEROLS
.
Taq DNA Polymerase A 94 kilodalton DNA
polymerase, which was originally isolated
© 2002 by CRC Press LLC

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from the thermophilic bacteria Thermus
aquaticus. Commonly utilized to catalyze
PCR reactions due to its heat resistance
(needed for thermal cycles utilized in the
PCR technique). See also 
DNA POLYMERASE
,
POLYMERASE
,
KILODALTON
  (
K
d
),
DEOXYRIBO-
NUCLEIC ACID
  (
DNA
),
BACTERIA
,
THERMOPHILIC
BACTERIA
,
PCR
,
POLYMERASE CHAIN REACTION
(
PCR
)
TECHNIQUE
.
Target (of a herbicide or insecticide) T h e
molecule (receptor, enzyme, etc.) within a
weed plant or within a pest insect that a given
herbicide or insecticide is “aimed” at (e.g.,
when scientists are conducting research
aimed at creating that herbicide or insecti-
cide). For example, glyphosate-containing
herbicides act on the (target) crucial plant
enzyme EPSP synthase. For example, insect-
resistant transgenic plants containing “B.t.
gene(s)” act on (target) receptors inside the
digestive system of specific insect species via
the B.t. protoxin. See also 
RECEPTORS
,
ENZYME
,
GLYPHOSATE
,
EPSP SYNTHASE
,
TRANSGENIC
(
ORGANISM
),
PROTOXIN
,
HERBICIDE
-
TOLERANT
CROP
,
PAT GENE
,
GLUTAMINE
,
GLUTAMINE SYN-
THETASE
,
CORN
,
BIOLOGICAL ACTIVITY
,
TARGET
-
LIGAND INTERACTION SCREENING
.