Biotechnology

part of the machinery of protein synthesis.
See also 
HEREDITY
,
GENETIC CODE
,
RIBOSOMES
,
INFORMATIONAL MOLECULES
,
NANOTECHNOLOGY
.
Ribose D-Ribose, a five-carbon-atom monosac-
charide (i.e., a sugar). It is important to life
because it and the closely allied compound
deoxyribose form a part of the molecules
© 2002 by CRC Press LLC

R
that constitute the backbone of nucleic acids.
See also 
NUCLEIC ACIDS
,
MONOSACCHARIDES
.
Ribosomal RNA See
r
RNA
 (
RIBOSOMAL RNA
).
Ribosomes The molecular “machines” within
cells that coordinate the interplay of tRNAs,
mRNAs, and proteins in the complex pro-
cess of protein synthesis (manufacture).
RNA constitutes nearly two-thirds of the
mass of these large (mega-Dalton) molecular
assemblies, which are technically ribozymes
(i.e., an enzyme in which the catalysis is
performed by RNA).
The formation of a ribosome (in the endo-
plasmic reticulum of a cell) from individual
RNA and protein molecules is largely a self-
assembly process, because all of the infor-
mation needed for the correct assembly of
this structure is contained in the primary
structure of its (molecular) components. The
assembly process is ordered and proceeds in
stages. Many ribosomes (in a given cell) can
simultaneously translate an mRNA molecule.
The structure, consisting of a group of ribo-
somes bound to an mRNA molecule actively
synthesizing protein, is called a polyribo-
some or a polysome. The ribosomes in this
(polysome) unit operate independently of
each other, each synthesizing a complete
polypeptide (protein) “molecular chain.” See
also
PROTEIN
,
POLYPEPTIDE
  (
PROTEIN
),
PROTEIN
SIGNALING
,
PROTEIN FOLDING
,
POLYCISTRONIC
,
PROTEIN STRUCTURE
,
PRIMARY STRUCTURE
,
TRAN-
SCRIPTION
,
TRANSCRIPTION UNIT
,
MESSENGER RNA
(
m
RNA
),
CELL
,
ENDOPLASMIC RETICULUM
  (
ER
),
TRANSFER RNA
 (
t
RNA
),
r
RNA
 (
RIBOSOMAL
r
RNA
),
DALTON
,
SELF
-
ASSEMBLY
 (
OF A LARGE MOLECU-
LAR STRUCTURE
),
RIBOZYMES
,
RIBONUCLEIC ACID
(
RNA
).
Ribozymes Discovered by Thomas Cech and
Sidney Altman, they are RNA molecules that
act as enzymes; that is, possess catalytic
activity and can specifically cleave (cut)
other RNA molecules. The ribozyme (RNA)
molecule and the other RNA molecule come
together, whereupon the ribozyme molecule
cuts the other RNA molecule at a specific
defined (three-base) site. Because the
ribozyme molecule acts as an enzyme in this
reaction, the ribozyme molecule is not con-
sumed or destroyed, but goes on to similarly
“cut” other RNA molecules. During 2000,
Thomas Steitz and Peter Moore, et al.,
proved that ribosomes (i.e., the cell’s internal
protein-synthesis “machinery”) are func-
tionally ribozymes. See also 
RIBONUCLEIC
ACID
  (
RNA
),
CATALYTIC RNA
,
BASE
  (
NUCLEO-
TIDE
),
ENZYME
,
CELL
,
RIBOSOMES
,
CATALYST
.
Ricin A lethal-to-cells protein naturally pro-
duced in castor beans. In 1994, Robert J. Ferl
and Paul C. Sehnke genetically engineered
a tobacco plant to produce ricin. Attached to
a pharmaceutical “guided missile” or “magic
bullet” such as a monoclonal antibody or the
CD4 protein, ricin is potentially useful for
treatment against some tumors and has been
investigated as a possible treatment against
acquired immune deficiency syndrome
(AIDS). See also 
IMMUNOTOXIN
,
MONOCLONAL
ANTIBODIES
 (
MA
b
),
CELL
,
CD
4
PROTEIN
,
GENETIC
ENGINEERING
,
FUSION PROTEIN
,
FUSION TOXIN
,
SOLUBLE CD
4
,
PHYTOCHEMICALS
, “
MAGIC BULLET
”.
Riken Japan’s Institute for Physical and
Chemical Research. See also 
RESEARCH FOUN-
DATION FOR MICROBIOLOGICAL DISEASES
.
RMD See
RAPID MICROBIAL DETECTION
.
RN Gene See
REDEMENT NAPOLE
 (
RN
)
GENE
.
RNA See
RIBONUCLEIC ACID
 (
RNA
).
RNA Polymerase An enzyme that catalyzes
the synthesis of a complementary mRNA
(messenger RNA) molecule from a DNA
(deoxyribonucleic acid) template in the pres-
ence of a mixture of the four ribonucleotides
(ATP, UTP, GTP, and CTP). Also called tran-
scriptase. See also 
CENTRAL DOGMA
,
POLY-
MERASE
,
DNA POLYMERASE
,
PROMOTER
.
RNA Probes See
DNA PROBE
.
RNA Transcriptase See
RNA POLYMERASE
.
RNA Vectors An RNA (ribonucleic acid)
vehicle for transferring genetic information
from one cell to another. See also 
VECTOR
,
RETROVIRAL VECTORS
.
Rootworm See
CORN ROOTWORM
.
ROS Acronym for Reactive Oxygen Species.
See also 
FREE RADICAL
.
Rosemarinic Acid A phenolic compound
(naturally found in some plants) that acts as
an antioxidant in the body’s tissues when
consumed by humans. For example, rose-
marinic acid is naturally produced in the edi-
ble herbs Origanum vulgare and Salvia
officinalis. See also 
PHYTOCHEMICALS
,
ANTIOX-
IDANTS
,
OXIDATIVE STRESS
,
NUTRACEUTICALS
.
© 2002 by CRC Press LLC

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Roving Gene See
JUMPING GENES
,
TRANSPOSI-
TION
,
TRANSPOSASE
,
GENE
,
GENOME
,
DEOXYRIBO-
NUCLEIC ACID
 (
DNA
).
Rps1c Gene A gene that confers to any soy-
bean plant (possessing that gene in its DNA)
resistance to several strains/races of phy-
tophthora root rot (PRR) disease. See also
GENE
,
DEOXYRIBONUCLEIC ACID
 (
DNA
),
SOYBEAN
PLANT
,
PHYTOPHTHORA ROOT ROT
.
Rps1k Gene A gene that confers to any soy-
bean plant (possessing that gene in its DNA)
resistance to as many as 21 strains/races of
phytophthora root rot (PRR) disease. See
also
GENE
,
DEOXYRIBONUCLEIC ACID
 (
DNA
),
PHY-
TOPHTHORA ROOT ROT
,
SOYBEAN PLANT
.
Rps6 Gene A gene that confers to any soybean
plant (possessing that gene in its DNA) resis-
tance to some strains/races of phytophthora
root rot (PRR) disease. See also 
GENE
,
DEOXY-
RIBONUCLEIC ACID
  (
DNA
),
PHYTOPHTHORA ROOT
ROT
,
SOYBEAN PLANT
.
rRNA (ribosomal RNA) The nucleic acid
component of ribosomes, making up approx-
imately two-thirds of the mass of the bacteria
Escherichia coli ribosome, and approxi-
mately one-half of the mass of mammalian
ribosomes. Ribosomal RNA accounts for
nearly 80% of the RNA content of the bac-
terial cell. See also 
NUCLEIC ACIDS
,
RIBOSOMES
,
ESCHERICHIA COLIFORM
  (
E
.
COLI
),
RIBONUCLEIC
ACID
 (
RNA
).
RT-PCR Acronym for Reverse Transcriptase
Polymerase Chain Reaction technique. See
also
REVERSE TRANSCRIPTASES
,
DNA POLY-
MERASE
,
POLYMERASE CHAIN REACTION
  (
PCR
),
POLYMERASE CHAIN REACTION
 (
PCR
)
TECHNIQUE
.
Rubitecan A pharmaceutical that either shrinks
or halts the growth of pancreatic cancer
tumors in humans. The pharmacophore (i.e.,
active portion of molecule) in rubitecan was
derived from a Chinese flowering tree (Camp-
totheca acuminata); thus that “family” of
drugs is known as camptothecins. Camptoth-
ecins inhibit a critical enzyme required for
cell division to occur (thus it inhibits rapidly
growing tumors). See also 
CANCER
,
PANCREAS
,
TUMOR
,
PHARMACOPHORE
,
ENZYME
.
Rumen (of cattle) See
PREBIOTICS
.
Rusts Various fungal diseases (puccinia spp.)
that attack small grain plants such as wheat,
corn/maize, sorghum, oats, barley and rye.
Its visual appearance is like that of rust on
the surfaces of those plants. See also 
FUNGUS
,
WHEAT
,
CORN
.
© 2002 by CRC Press LLC

0-8493-XXXX-X/01/$0.00+$1.50
© 2001 by CRC Press LLC
S
S
S1 Nuclease An enzyme that specifically
degrades (destroys) single-stranded
sequences of DNA. See also 
RESTRICTION
ENDONUCLEASES
,
ENZYME
,
DEOXYRIBONUCLEIC
ACID
 (
DNA
).
SAAND Acronym for Selective Apoptotic
Anti-Neoplastic Drug. See also 
SELECTIVE
APOPTOTIC ANTI
-
NEOPLASTIC DRUG
 (
SAAND
).
SAGB Senior Advisory Group on Biotechnol-
ogy. See also 
SENIOR ADVISORY GROUP ON BIO-
TECHNOLOGY
 (
SAGB
).
Salicylic Acid (SA) SA is a signaling mole-
cule in Systemic Acquired Resistance (SAR)
when SAR is triggered in plants (e.g., via
spray application of COBRA R herbicide to
soybean plants, via spray application of
harpin protein to various plants, via chewing
by insects on the leaves of tomato plants,
and/or the entry-into-plant of certain patho-
genic bacteria/fungi, etc.). See also 
SYSTEMIC
ACQUIRED RESISTANCE
  (
SAR
),
SIGNALING MOLE-
CULE
,
SOYBEAN PLANT
,
HARPIN
,
FUNGUS
,
PATHO-
GEN
,
PROTEIN
,
PATHOGENESIS RELATED PROTEINS
,
JASMONIC ACID
.
Salinity Tolerance See
SALT TOLERANCE
.
Salmonella A genus of bacteria, consisting of
more than 2,400 serovars (strains/types)
classified within two species (Salmonella
enterica and Salmonella bongori). All of
these serovars are potentially pathogenic
(disease-causing) to humans. For example,
some variants of Salmonella typhimurium
can cause typhoid fever. The nontyphoid
strains of Salmonella generally cause entero-
colitis; although that enterocolitis can lead
to more serious systemic infections. Salmo-
nella enteritidis and Salmonella typhimurium
are increasingly causing outbreaks of food-
borne illnesses (e.g., when foods are not
washed or cooked thoroughly enough prior to
consumption by humans). See also 
BACTERIA
,
PATHOGEN
,
PATHOGENIC
,
STRAIN
,
COMMENSAL
.
Salmonella enteritidis (Se) A   p a t h o g e n i c
strain of Salmonella bacteria that can cause
fatal infections in poultry and humans (e.g.,
when undercooked eggs are eaten by
humans). See also 
BACTERIA
,
PATHOGEN
,
PATHOGENIC
,
STRAIN
,
SALMONELLA
.
Salmonella typhimurium A pathogenic strain
of Salmonella bacteria, which can cause dis-
ease in humans (e.g., when contaminated
food is not washed and cooked enough prior
to consumption). See also 
BACTERIA
,
PATHO-
GEN
,
PATHOGENIC
,
STRAIN
,
COMMENSAL
.
Salt Tolerance Refers to the trait (of a plant)
that enables a plant to grow/survive in soil
that contains a high level of salt. For exam-
ple, during 2001, Eduardo Blumwald and
Hong-Xia Zhang inserted a salt-tolerance
gene from Arabidopsis thaliana into a
tomato plant (Lycopersicon esculentum) and
thereby made that tomato plant resistant to
salt concentrations up to 200 mM (far higher
than it could previously survive). That (Ara-
bidopsis origin) gene enables the tomato
plant to extract salt from the soil, and then
sequester and store the salt in vacuoles (i.e.,
small compartments) within its leaf cells.
See also 
ARABIDOPSIS THALIANA
,
VACUOLES
.
Salting Out A technique used for forcing (dis-
solved) proteins out of a solution by increas-
ing the concentration of salt in the solution.
The Na
+
 and Cl
–
 ions derived from the salt
compete for and “tie up” water molecules
that are solubilizing the protein molecules,
thereby rendering them insoluble or more
insoluble.
SAM See
SAM
-
K GENE
.
Sam-K Gene A gene naturally present within
the E. coli bacteriophage T3. If the sam-k
© 2002 by CRC Press LLC

S
gene is inserted via genetic engineering into
a (fruit crop) plant’s genome, that causes
greatly reduced production of the chemical
compound S-adenosylmethionine (SAM) in
that plant’s fruit. Because the SAM is nor-
mally converted (chemically) into l-ami-
nocyclopropane-1-carboxylic acid (ACC) in
the fruits of traditional vaieties of (fruit crop)
plants, such sam-k gene-containing plants
produce fruits which ripen/soften far slower
than fruit from traditional varieties of those
plants; which can reduce spoilage/loss in the
harvest and transport of such fruit. That is
because ACC is required for fruits to pro-
duce ethylene, the plant hormone which trig-
gers (over-) ripening/softening of fruit. See
also
GENE
,
BACTERIOPHAGE
,
ESCHERICHIA
COLIFORM
  (
E
.
COLI
),
GENETIC ENGINEERING
,
GENOME
,
ACC
,
ACC SYNTHASE
.
Sanitary and Phytosanitary (SPS) Agree-
ment The agreement to GATT/WTO via
which WTO member nations agreed to base
their technical barriers (regarding some
imports, designed for the protection of
human health or the control of animal and
plant pests/diseases) only on an assessment
of actual risks posed by the particular import
in question; and to utilize only scientific
methods in assessing those risks. See also
SANITARY AND PHYTOSANITARY
 (
SPS
)
MEASURES
,
WORLD TRADE ORGANIZATION
 (
WTO
),
SPS
.
Sanitary and Phytosanitary (SPS) Measures
Technical barriers (i.e., against some
imports) that are designed for the protection
of human health or the control of animal and
plant pests/diseases. In the Sanitary and Phy-
tosanitary (SPS) Agreement to GATT/WTO,
the WTO member nations agreed to base
their SPS measures only on an assessment
of actual risks posed by the particular import
in question, and to utilize only scientific
methods in assessing those risks. See also
SANITARY AND PHYTOSANITARY
 (
SPS
)
AGREEMENT
,
WORLD TRADE ORGANIZATION
 (
WTO
),
SPS
.
Saponification Alkaline hydrolysis of triacyl
glycerols to yield fatty acid salts. The mol-
ecules thus produced are known as surfac-
tants (surface active agents), commonly
called soap. The process of soapmaking. See
also
HYDROLYSIS
.
Saponins A group of phytochemicals (i.e.,
sugars linked to a triterpene or a steroid
molecular subunit) produced by certain
plants (the soybean plant, spinach plant,
tomatoes, potatoes, ginseng plant, etc.). Evi-
dence suggests that human consumption of
saponins (e.g., produced in soybeans) can
help to lower a person’s blood content of
low-density lipoproteins (LDLP) and can
help prevent certain types of cancer. See also
PHYTOCHEMICALS
,
SUGAR MOLECULES
,
SOYBEAN
PLANT
,
LOW
-
DENSITY LIPOPROTEINS
 (
LDLP
),
CAN-
CER
,
STEROID
.
SAR Acronym for Systemic Acquired Resis-
tance. See also 
SYSTEMIC ACQUIRED RESISTANCE
(
SAR
).
Satellite DNA Many tandem repeats (identical
or related) of a short basic repeating unit (in
the DNA molecule). See also 
DEOXYRIBO-
NUCLEIC ACID
 (
DNA
).
Saturated Fatty Acids (SAFA) Fatty acids
containing fully saturated alkyl chains (on
their molecules). This means that the carbon
atoms comprising the chains are held
together by one carbon-to-carbon bond and
not two or three. High levels of dietary
SAFA have been related to increased blood
cholesterol levels, which tends to lead to
coronary heart disease (CHD) in humans.
The sole exception is stearic acid (also
known as stearate), which research has
shown has no impact on the blood choles-
terol levels of humans that consume it. Beef
fat typically contains approximately 54%
saturated fatty acids; sheep fat typically con-
tains approximately 58% saturated fatty
acids; pork fat typically contains approxi-
mately 45% saturated fatty acids; chicken fat
typically contains approximately 32% satu-
rated fatty acids.
In general, fats possessing the highest lev-
els of saturated fatty acids tend to be solid
at room temperature; and those fats possess-
ing the highest levels of unsaturated fatty
acids tend to be liquid at room temperature.
That rule of thumb was the original “divid-
ing line” between the terms “fats” and “oils,”
respectively. See also 
FATTY ACID
,
DEHYDRO-
GENATION
,
CHOLESTEROL
,
MONOUNSATURATED
FATS
,
SAPONIFICATION
,
LPAAT PROTEIN
,
UNSAT-
URATED FATTY ACID
,
POLYUNSATURATED FATTY
© 2002 by CRC Press LLC

S
ACIDS
 (
PUFA
),
CORONARY HEART DISEASE
 (
CHD
),
PALMITIC ACID
,
STEARATE
 (
STEARIC ACID
),
HIGH
-
STEARATE SOYBEANS
,
HIGH
-
STEARATE CANOLA
.
Saxitoxins Paralytic poisons produced by cer-
tain shellfish. See also 
RICIN
.
SBO Soybean oil.
Scab See
FUSARIUM
.
Scale-Up The transition step in moving a
(chemical) process from experimental (e.g.,
“test tube,” small, bench) scale to a larger
scale producing more or much more product
that the bench scale (e.g., production of
tons/year in a chemical plant). A process
may require a number of scale-ups, with
each scale-up producing more product than
the last one.
Scanning Tunneling Electron Microscopy
See
ELECTRON MICROSCOPY
 (
EM
).
SCP See
SINGLE
-
CELL PROTEIN
 (
SCP
).
SDM Site-directed mutagenesis. See also 
SITE
-
DIRECTED MUTAGENESIS
 (
SDM
).
SDS Sodium dodecyl sulfate. Also known as
sodium lauryl sulfate (SLS). A surfactant
commonly used in biochemical and biotech-
nological applications for the solubilization
of membrane components and hard-to-solu-
bilize (dissolve) molecules. For example, it
is often utilized at high concentration in
water solution (e.g., along with potassium
acetate) to dissolve plant DNA samples (e.g.,
when a scientist wants to sequence that sam-
ple of plant DNA). The SDS/PA in water
solution helps the scientist to separate out
contaminants commonly present in samples
from plant tissues (polysaccharides, pro-
teins, etc.) because DNA molecules are
much more soluble in SDS/PA solution than
are those contaminant molecules. Above a
critical concentration (CMC), SDS forms
micelles in water which are thought to be
responsible for its solubilizing action. SDS is
also used in such items as shampoo. See also
CRITICAL MICELLE CONCENTRATION
,
MICELLE
,
REVERSE MICELLE
 (
RM
),
PROTEIN
,
MEMBRANE
 (
OF
A CELL
),
SURFACTANT
,
DEOXYRIBONUCLEIC ACID
(
DNA
),
POLYSACCHARIDES
,
SEQUENCING
 (
OF DNA
MOLECULES
),
HEXADECYLTRIMETHYLAMMONIUM
BROMIDE
 (
CTAB
).
Seed-Specific Promoter See
PROMOTER
.
“Seedless” Fruits See
TRIPLOID
.
Selectable Marker Genes See
MARKER
 (
GENETIC
MARKER
).
Selectins Also called LEC-CAMs (leukocyte-
cell adhesion molecules). A class of molecu-
lar structurally related lectins that mediate
(control, cause, etc.) the contacts between a
variety of cells (e.g., leukocytes and endo-
thelial cells), and function as cellular adhe-
sion receptors. See also 
RECEPTORS
,
LECTINS
,
ADHESION MOLECULE
,
LEUKOCYTES
,
ENDOTHELIAL
CELLS
,
ENDOTHELIUM
,
SIGNAL TRANSDUCTION
.
Selective Apoptotic Anti-Neoplastic Drug
(SAAND) A category of pharmaceuticals
that acts to prevent neoplastic growth (i.e.,
cancer) by allowing normal cell apoptosis to
occur again (e.g., by blocking an enzyme that
is hindering normal apoptosis) in abnormal
precancerous cells and cancerous cells.
Examples of SAANDs include sulindac,
which blocks phosphodiesterases (enzymes).
See also 
NEOPLASTIC GROWTH
,
CANCER
,
TUMOR
,
APOPTOSIS
,
CELL
,
ENZYME
,
PHOSPHODIESTERASES
.
Selective Estrogen Effect A term used to
describe how certain phytochemicals (fla-
vones, flavonols, isoflavones, etc.) and phar-
maceuticals (Evista/raloxifene, tamoxifen,
etc.) possessing molecular structures that are
similar to estrogen (a hormone) impart some
beneficial effect on the human body when
consumed by humans, without any of the
adverse impacts of estrogen (e.g., promotion
of the growth of certain tumors by estrogen).
See also 
PHYTOCHEMICALS
,
FLAVONOLS
,
ISOFLA-
VONES
,
FLAVONOIDS
,
ESTROGEN
,
PHYTOESTRO-
GENS
,
PROSTATE
,
GENISTEIN
 (
G
en
).