Biotechnology

N
H Y B R I D I Z A T I O N
  (
M O L E C U L A R
G E N E T I C S
),
SEQUENCE
  (
OF A DNA MOLECULE
),
VIRUS
,
BIO-
SENSORS
  (
CHEMICAL
),
BIOCHIP
,
MICROFLUIDICS
,
NANOCRYSTALS
.
Nanocrystals A term used to refer to any crys-
talline structure possessing dimensions (e.g.,
overall width) measured in terms of nanom-
eters. See also 
NANOMETERS
  (
NM
),
QUANTUM
DOT
,
NANOSCIENCE
,
NANOTECHNOLOGY
,
NANOC-
RYSTAL MOLECULES
,
NANOCOMPOSITES
.
Nanoelectromechanical System (NEMS)
Refers to working (i.e., those with moving
“mechanical parts”) systems of a scale
whose relevant dimensions are measured in
terms of nanometers (nm). For example, in
2000, Carlo Montemagno and colleagues
assembled a NEMS in which a tiny metal
“propeller” was caused to spin within the
domain of the enzyme ATP Synthase. The
metal propeller was attached (via a biotin-
streptavidin “molecular linkage”) to the one
subunit (designated alpha) of ATP Synthase
that rotates within the other (hollow) part of
ATP Synthase molecule when ATP is “fed”
to a free standing (i.e., not in cell) molecule
of ATP Synthase. See also 
NANOMETERS
 (
NM
),
ATP SYNTHASE
,
ENZYME
,
ADENOSINE TRIPHOS-
PHATE
 (
ATP
),
BIOTIN
,
AVIDIN
,
NANOCOMPOSITES
,
NANOSCIENCE
,
MICROMACHINING
.
Nanofluidics See
MICROFLUIDICS
.
Nanogram (ng) 10
–9
 gram, or 3.527 
× 10
–11
ounce (avoirdupoir).
Nanometers (nm) 10
–9
 meter. Often used to
express wavelengths of light (e.g., in a spec-
trophotometer), or to express dimensions of
nanocomposites, devices (e.g., of miniature
“machines” called nanoelectromechanical
systems), etc. in the field of nanotechnology.
See also 
SPECTROPHOTOMETER
,
NANOTECHNOL-
OGY
,
NANOCOMPOSITES
,
NANOELECTROMECHANI-
CAL SYSTEM
 (
NEMS
),
MICROFLUIDICS
,
METER
.
Nanoparticles See
NANOCRYSTALS
,
NANOCRYS-
TAL MOLECULES
,
NANOTECHNOLOGY
.
Nanopore A device that can distinguish
between DNA strands (molecules) that differ
from each other by a single nucleotide (in
the makeup of those molecular strands).
Developed by David Deamer and Mark Ake-
son in 2001, it consists of an artificial mem-
brane (lipid bilayer) with a “hole”
(nanopore) punctured in that membrane by
the protein alpha-hemolysin. Because a
DNA molecule moving through such a nan-
opore temporarily blocks the nanopore (until
it dissociates into a single DNA strand and
“slides” through), an electrical current/volt-
age applied to that nanopore varies (in
amplitude, modulation, duration, etc.) as the
DNA strand “slides through,” in a way that
provides information (e.g., to scientist)
about the nucleotides that makeup that DNA
strand. It is expected that nanopores will also
be used for DNA sequencing. See also 
NANO-
SCIENCE
,
NANOMETERS
 (
NM
),
NANOTECHNOLOGY
,
PLASMA MEMBRANE
,
MICELLE
,
DEOXYRIBO-
NUCLEIC ACID
  (
DNA
),
NUCLEOTIDE
,
SINGLE
-
NUCLEOTIDE POLYMORPHISM
  (
SNP
),
ION CHAN-
NELS
,
SEQUENCING
 (
OF DNA MOLECULES
).
Nanoscience A term utilized to refer to the
science underlying nanotechnology, nano-
crystals, nanocrystal molecules, nanocompos-
ites, “quantum dots,” nanoelectromechanical
systems (NEMS), etc. “Nanoscale” materi-
als (i.e., those whose dimensions are approx-
imately 1 to 100 nanometers) generally
possess different chemical and physical
properties than “bulk” materials. For exam-
ple, when bulk gold metal is formed into
nanoscale rods, the intensity of its fluores-
cence increases by a factor of approximately
10 million. Another example is that silicon
nanocrystals (i.e., quantum dots) dispersed
in a silicon dioxide matrix, emit larger-than-
typical-for-silicon amounts of light, when
stimulated (i.e., bombarded) with pulses of
ultraviolet light. See also 
NANOTECHNOLOGY
,
NANOCRYSTALS
,
QUANTUM DOT
,
NANOCRYSTAL
MOLECULES
,
NANOCOMPOSITES
,
NANOELECTRO-
MECHANICAL SYSTEM
  (
NEMS
),
SELF
-
ASSEMBLY
(
OF A LARGE MOLECULAR STRUCTURE
),
NANOPORE
,
MICROFLUIDICS
.
Nanotechnology From the Latin nanus, dwarf,
so it literally means “dwarf technology.” The
word was originally coined by Norio Tan-
iguchi in 1974, to refer to high precision
machining. However, Richard Feynman and
K. Eric Drexler later popularized the concept
of nanotechnology as a new and developing
technology in which man manipulates
objects whose dimensions are approximately
1 to 100 nanometers. Theoretically, it is pos-
sible that in the future a variety of man-made
© 2002 by CRC Press LLC

N
“nano-assemblers” [tiny (molecular)
machines smaller than a grain of sand]
would manufacture those things that are pro-
duced today in factories. For example,
enzyme molecules function essentially as
jigs and machine tools to shape large mole-
cules as they are formed in biochemical reac-
tions. The technology also encompasses
biochips, biosensors, and manipulating
atoms and molecules in order to form (build)
bigger, but still vanishingly small functional
structures and machines. See also 
ENZYME
,
GENOSENSORS
,
NANOMETERS
  (
NM
),
BIOSENSORS
(
ELECTRONIC
),
BIOCHIP
,
MICROFLUIDICS
,
NANO-
CRYSTALS
,
NANOCRYSTAL MOLECULES
,
BIOSENSORS
(
CHEMICAL
),
QUANTUM DOT
,
NANOCOMPOSITES
,
NANOELECTROMECHANICAL SYSTEM
  (
NEMS
),
SELF
-
ASSEMBLY
 (
OF A LARGE MOLECULAR STRUC-
TURE
),
NANOPORE
,
BIOMEMS
.
Nanotube See
NANOSCIENCE
,
NANOTECHNOLOGY
,
SELF
-
ASSEMBLY
  (
OF A LARGE MOLECULAR
STRUCTURE
).
Napole Gene See
REDEMENT NAPOLE
 (
RN
)
GENE
.
NAS See
NATIONAL ACADEMY OF SCIENCES
.
National Academy of Sciences (NAS) A pri-
vate, self-perpetuating society of distin-
g u i s h e d   s c h o l a r s   i n   s c i e n t i fi c   a n d
engineering research, dedicated to the
advancement of science and technology and
their use for the general welfare. Under the
authority of its congressional charter of
1863, the NAS has a working mandate that
calls upon it to advise the U.S. Federal Gov-
ernment on scientific and technical matters.
See also 
VITAMIN E
.
National Cancer Institute (NCI) One of the
National Institutes of Health. See also
NATIONAL INSTITUTE OF HEALTH
 (
NIH
).
National Heart, Lung, and Blood Institute
(NHLBI) One of the National Institutes of
Health. See also 
NATIONAL INSTITUTES OF
HEALTH
 (
NIH
).
National Institute of Allergy and Infectious
Diseases (NIAID) The main agency of the
National Institutes of Health. See also
NATIONAL INSTITUTES OF HEALTH
 (
NIH
).
National Institute of General Medical Sci-
ences (NIGMS) One of the National Insti-
tutes of Health. See also 
NATIONAL INSTITUTES
OF HEALTH
 (
NIH
).
National Institutes of Health (NIH) The
major U.S. Government sponsor of biotech-
nology research. It is composed of a group
of government institutes that each focus on
specific medical areas. See also 
RECOMBINANT
DNA ADVISORY COMMITTEE
 (
RAC
).
Native Conformation The normal, biologi-
cally active conformation (i.e., the three-
dimensional arrangement of its atoms) of a
protein molecule. See also 
CONFORMATION
.
Naturaceuticals See
NUTRACEUTICALS
.
Natural Killer Cells These cells are involved
in tumor surveillance. They also kill virus-
laden cells.
NCI See
NATIONAL CANCER INSTITUTE
 (
NCI
).
NDA (to FDA) New Drug Application (to the
U.S. Food and Drug Administration). A
(paper) application to the U.S. Food and
Drug Administration (FDA) seeking
approval of a new drug that has undergone
Phase 2 and Phase 3 clinical trials. An NDA
is submitted in the form of (thousands of)
pages of (clinical and other) data, along with
various analyses (e.g., statistical) of that data
for efficacy, safety, etc. See also 
CANDA
,
FOOD
AND DRUG ADMINISTRATION
 (
FDA
),
MAA
,
NDA
 (
TO
KOSEISHO
),
PHASE I CLINICAL TESTING
.
NDA (to Koseisho) New drug application. It
is the Japanese equivalent to a U.S. IND
(investigational new drug) application; to the
Koseisho, the Japanese equivalent of the
U.S. Food and Drug Administration (FDA).
See also 
IND
,
KOSEISHO
,
FOOD AND DRUG ADMIN-
ISTRATION
 (
FDA
).
Near-Infrared Spectroscopy (NIR) Refers to
analytical instruments which shine light
(possessing wavelengths between that of vis-
ible light and infrared light spectrum) onto
samples (e.g., kernels of grain) and measure
the reflected or transmitted (near-infrared)
light in order to quickly determine the
amounts of protein, fat, moisture, lignans,
etc. present in the sample. In certain sam-
ples, the near-infrared light causes cells (or
specific molecules) to fluoresce (i.e., as light
of very defined wavelength), which can sub-
sequently be utilized for measurement/iden-
tification of compounds within the sample.
NIR is also being developed for use in quan-
tifying (e.g., amounts that are present within
the sample) of immunoassays and detection
© 2002 by CRC Press LLC

N
of specific molecules (e.g., in DNA sequenc-
ing process). See also 
PROTEIN
,
FATS
,
LIGNANS
,
IMMUNOASSAY
,
FLUORESCENCE
,
SEQUENCING
 (
OF
DNA MOLECULES
).
Near-Infrared Transmission (NIT) Refers to
certain analytical instruments which shine
light (possessing wavelengths between that
of visible light and infrared spectrum)
through samples (e.g., kernels of grain) in
order to quickly determine the amounts of
protein, fat, moisture, lignans, etc. present in
the sample. See also 
PROTEIN
,
FATS
,
LIGNANS
,
NEAR
-
INFRARED SPECTROSCOPY
 (
NIR
).
Necrosis Refers to cell death caused by phys-
ical injury to the cell (e.g., exposure to toxin,
exposure to ultraviolet light, lack of oxygen,
etc.). See also 
CELL
,
TOXIN
,
RESPIRATION
,
TUMOR NECROSIS FACTOR
.
Neem Tree A tropical tree (Azadirachta
indica) found in India, Somalia, Mauritania,
Australia, and other tropical countries; that
resists insect (e.g., whiteflies, mealybugs,
aphids, mites) depradations and certain fun-
gal diseases (rusts, powdery mildew, etc.) via
secretions of liquids that contain Azadirach-
tin (an insect-repelling chemical). See also
AZADIRACHTIN
,
FUNGUS
.
Negative Supercoiling Comprises the twist-
ing of a duplex of DNA (deoxyribonucleic
acid) in space in the opposite sense to the
turns of the strands in the double helix. See
also
DOUBLE HELIX
.
Nematodes Microscopic roundworms, which
are the most abundant multi-celled creatures
on earth. They are primarily found living in
soil. One nematode named Caenorhabditis
elegans  (C. elegans) is commonly used by
scientists in genetics experiments, so a large
base of knowledge about its genetics has
been accumulated by the world’s scientific
community. For example, of the nearly 300
“disease-causing” genes in the human
genome, more than half of them have an
analogous gene within the genome of
C. elegans. One Antarctic nematode (Pana-
grolaimus davidi) is able to survive Antarctic
winters by drying out and achieving a state
of “suspended animation” (anhydrobiosis)
for as long as thirty-nine years. See also
CELL
,
CAENORHABDITIS ELEGANS
  (
C
.
ELEGANS
),
GENETICS
,
GENE
,
GENOME
,
GENETIC MAP
,
MODEL
ORGANISM
,
SOYBEAN CYST NEMATODES
  (
SCN
),
CYSTX
.
NEMS See
NANOELECTROMECHANICAL SYSTEM
(
NEMS
).
Neoplasia New growth. See also 
NEOPLASTIC
GROWTH
.
Neoplastic Growth A new growth of animal
or plant tissue resembling (more or less) the
tissue from which it arises but having dis-
tinct biochemical differences from the parent
cell. The neoplastic tissue is a mutant version
of the original and appears to serve no phys-
iologic function in the same sense as did the
original tissue. It may be benign or malig-
nant (i.e., a cancerous tumor). See also
TUMOR
,
CANCER
,
SELECTIVE APOPTOTIC ANTI
-
NEOPLASTIC DRUG
 (
SAAND
),
METASTASIS
.
Nerve Growth Factor (NGF) A protein pro-
duced by the salivary glands (and also in
tumors) that greatly increases growth/repro-
duction of nerve cells and guides the forma-
tion of neural networks. In the brain, NGF
is thought to increase the production of the
messenger chemical, acetylcholine, by pro-
tecting and stimulating those neurons that
produce acetylcholine. Because those (ace-
tylcholine-producing) neurons are typically
the first to be destroyed in an Alzheimer’s
disease victim, NGF holds potential to be
used to counteract (some of) the effects of
the disease.
NGF is also necessary for normal devel-
opment of the hypothalamus, a brain struc-
ture that regulates a number of hormones.
Human T cells appear to have receptors for
NGF, which could explain the “mind–body
connection” between a person’s emotional
well-being and physical health (i.e., NGF
may be a go-between for the brain and the
immune system). NGF was discovered by
Rita Levi-Montalcini in 1954. See also
GROWTH FACTOR
,
EPIDERMAL GROWTH FACTOR
(
EGF
),
HYPOTHALAMUS
,
HORMONE
,
PROTEIN
.
Nested PCR Refers to a specific PCR (poly-
merase chain reaction) technique of two con-
secutive-run PCRs, in which the second PCR
amplifies (i.e., makes multiple copies of) a
DNA sequence within the product (ampli-
con) of the first PCR. See also 
POLYMERASE
CHAIN REACTION
  (
PCR
),
POLYMERASE CHAIN
REACTION
  (
PCR
)
TECHNIQUE
,
SEQUENCE
  (
OF A
© 2002 by CRC Press LLC

N
DNA MOLECULE
),
DEOXYRIBONUCLEIC ACID
(
DNA
),
AMPLICON
.
Neuraminidase (NA) A transmembrane (i.e.,
through the membrane) glycoprotein
enzyme that appears in the (external) mem-
brane of the influenza virus. See also
ENZYME
,
GLYCOPROTEIN
,
VIRUS
.
Neuron Cells of the body’s nervous system,
which transmit nerve impulses (electrical sig-
nals conducted by the flow of ions across the
plasma membrane of neuron cells). Neurons
are involved in controlling movement (known
as motor control), emotions, and memory.
There are approximately 100 billion neurons
in the typical human brain. The nerve impulses
within them move at a speed of approximately
400 kilometers per hour (300 miles per hour).
See also 
NEUROTRANSMITTER
,
ACETYLCHOLINE
,
SEROTONIN
,
CELL
,
PARKINSON
’
S DISEASE
,
PLASMA
MEMBRANE
,
ION
,
DENDRITES
.
Neurotransmitter An organic, low molecular
weight compound that is secreted from the
(axon) terminal end of a neuron (in response
to the arrival of an electrical impulse) into a
liquid-filled gap that exists between neurons.
The transmitter molecule then diffuses
across the small gap and attaches to the next
neuron. This attachment causes structural
changes in the membrane of the neuron and
initiates the conductance of an electrical
impulse. In this way, an electrical impulse is
transmitted (via this “cascade”) along a neu-
ron network of which the neurons them-
selves do not physically touch.
A neurotransmitter serves to transmit a
nerve impulse between different neurons.
Examples of neurotransmitters include
dopamine and norepinephrine. A shortage of
dopamine in the brain causes the disease
known as Parkinson’s disease. See also
MOLECULAR WEIGHT
,
NEURON
,
SEROTONIN
,
ACETYLCHOLINE
,
PARKINSON
’
S DISEASE
,
CASCADE
,
DENDRITES
.
Neutraceuticals See
NUTRACEUTICALS
.
Neutriceuticals See
NUTRACEUTICALS
.
Neutrophils Phagocytic (ingesting, scaveng-
ing) white blood cells produced in the bone
marrow. They ingest and destroy invading
microorganisms and facilitate post-infection
tissue repair. They can secrete collagenase
and plasminogen activator. They are the
immune system’s “first line” of defense
against invading pathogens, and large
reserves are called forth within hours of the
start of a “pathogen invasion.” See also
PATHOGEN
,
COLLAGENASE
,
MICROORGANISM
.
New Drug Application See
NDA
 (
TO KOSEISHO
),
NDA
 (
TO FDA
),
MAA
,
IND
,
CANDA
.
NIAID See
NATIONAL INSTITUTE OF ALLERGY AND
INFECTIOUS DISEASES
.
Nick A break in one strand of a double-
stranded DNA molecule. One of the phos-
phodiester bonds between two adjacent
nucleotides is ruptured. No bases are
removed from the strand, it is just opened at
that point. See also 
DEOXYRIBONUCLEIC ACID
(
DNA
).
Nicotine-Adenine Dinucleotide (NAD) S e e
NAD
.
Nicotine-Adenine Dinucleotide Phosphate
(NADP) See
NAD
.
Nicotine-Adenine Dinucleotide Phosphate,
reduced (NADPH) See
NAD
.
Nicotine-Adenine Dinucleotide, reduced
(NADH) See
NAD
.
NIH See
NATIONAL INSTITUTES OF HEALTH
 (
NIH
).
NIHRAC See
RECOMBINANT DNA ADVISORY COM-
MITTEE
 (
RAC
).
Ninhydrin Reaction A color reaction given
by amino acids and peptides on heating with
the chemical ninhydrin. The technique is
widely used for the detection and quantita-
tion (measurement) of amino acids and pep-
tides. The concentration of amino acid in a
solution (of hydrochloric acid) is propor-
tional to the optical absorbance of the solu-
tion after heating it with ninhydrin. 
α-Amino
acids give an intense blue color, and amino
acids (such as proline) give a yellow color.
One is able to determine concentration of a
protein or peptide and also obtain an idea of
the type of protein or peptide that is present.
See also 
ABSORBANCE
 (
A
),
AMINO ACID
,
PEPTIDE
.
Nitrate Bacteria See
N I T R A T E S
,
N I T R I T E S
,
BACTERIA
.
Nitrate Reduction The reduction of nitrate to
nitrite or ammonia by an organism. See also
NITRATES
,
REDUCTION
 (
IN A CHEMICAL REACTION
),
NITRITES
.
Nitrates Refers to nitrogen compounds that
exist in a chemical form which plant roots
are able to take in (i.e., utilized by the plant
© 2002 by CRC Press LLC

N
to make nitrogen-containing molecules such
as proteins). Nitrates are produced from
nitrogen:
• Taken out of the atmosphere by nitro-
gen-fixing bacteria (living among the
roots of legume plants such as the soy-
bean, etc.)
• Taken out of nitrites (in soil) by nitrate
bacteria
• Taken out of the atmosphere by blue-
green algae
See also 
PROTEIN
,
NITROGEN FIXATION
,
SOYBEAN
PLANT
,
NITRITES
.
Nitric Oxide Abbreviated NO, it is a molecule
produced in the body of an organism, which
can act as:
• A signaling molecule (e.g., to cause a
firefly’s tail to begin the chemical reac-
tion of luciferin with luciferase that
results in the light emission known as
bioluminescence)
• An oxidant utilized against pathogens
by the immune system
• An instigator of (destructive) free radicals
• An inducer of genes (e.g., in soybean
plants) that cause production of certain
chemical compounds which protect the
organism (e.g., soybean plant) from
bacterial diseases
As a signaling molecule, or “messenger mol-
ecule,” nitric oxide is utilized by the human
body for control of blood pressure (i.e.,
when the endothelial cells that line blood
vessels produce NO that causes neighboring
smooth-muscle cells to relax so entire blood
vessel dilates; thereby lowering blood pres-
sure). Nitric oxide is also utilized by the
human body for immune system regulation,
and its synthesis in macrophages is required
for macrophages to kill pathogens and tumor
cells (by oxidizing them after the macro-
phage has engulfed them).
During the 1980s, John Garthwaite and
Solomon H. Snyder showed that nitric oxide
is an important messenger molecule utilized
in neural signaling (i.e., NO is an important
signaling molecule in the human brain).
Nitric oxide increases the effectiveness of
reactive free radicals (e.g., superoxide O
2
) in
killing off any infected cells within a soybean
plant. Nitric oxide also induces certain genes
to code for the production of certain chemical
compounds that protect the soybean plant
from bacterial plant diseases. See also 
SIG-
NALING MOLECULE
,
SIGNALING
,
OXIDIZING AGENT
,
PATHOGEN
,
IMMUNE RESPONSE
,
HUMAN SUPEROX-
IDE DISMUTASE
  (
h
SOD
),
SIGNAL TRANSDUCTION
,
NITRIC OXIDE SYNTHASE
,
SOYBEAN PLANT
,
PRO-
TEIN
,
INDUCERS
,
GENE
,
CODING SEQUENCE
,
FREE
RADICAL
,
ENDOTHELIAL CELLS
,
ENDOTHELIUM
,
MACROPHAGE
,
PATHOGEN
,
BACTERIA
,
TUMOR
,
NEUROTRANSMITTER
,
BIOLUMINESCENCE
.