ATP (adenosine
triphosphate)
a common source of activation energy for
metabolic reaction.
Glossary
Absorption: the process in which nutrients enter cells of the villi, then move across the cells and enter blood vessels.
Acetylcholinesterase,
also known as AChE, is an enzyme that degrades
(through its hydrolytic activity) the neurotransmitter
acetylcholine, producing choline and an acetate group.
It is mainly found at neuromuscular junctions and
cholinergic synapses in the central nervous system,
where its activity serves to terminate synaptic
transmission.
Actin:
a
protein
filament
within
the
sarcomeres
of
muscle
cells.
Adhesin: A
molecular component of the surface of a microorganism
that is involved in adhesion to a substratum or cell.
Adhesion to a specific host tissue usually is a
preliminary stage in pathogenesis, and adhesins are
important virulence factors.
Acidophile: A microorganism that has its growth optimum between about pH 0 and 5.5.
Aerobe: An
organism that grows in the presence of atmospheric
oxygen.
Aflatoxin:
A polyketide secondary
fungal metabolite that can cause cancer.
Algicide: An agent that kills algae.
Alleles: Alternative forms of a genetic
characteristic. Amensalism:
A symbiotic relationship in which one
organism is harmed or inhibited and the other is
unaffected.
Anabolism:
the process of synthesizing
large molecules by joining
smaller molecules together.
Anaerobic:
organisms that thrive in an
oxygen-free environment.
Anaphase: stage in mitosis and meiosis where chromosomes begin moving to opposite ends (poles) of the cell.
Anatomy:
the study of the structure and relationship
between body parts.
Annotation: The
process of determining the location of specific genes in
a genome map after it has been produced by nucleic acid
sequencing.
Antagonistic hormones:
hormones that
act to return body conditions to within acceptable
limits from opposite extremes.
Antigen:
any molecule, usually a protein
or polysaccharide, that can be identified as
foreign or nonself. It may be a toxin, or a part
of the protein coat of a virus, or a molecule
unique to the plasma membranes.
Aquaculture – the farming of marine and fresh
water organisms.
Atoll – a coral
reef that develops as a ring around a central lagoon. Autosome: All
chromosomes except those involved in sex determination.
Humans have 22 pairs of autosomes and the X and Y sex
chromosomes (XX for females, YY for males).
Alveoli:
microscopic air sacs that are surrounded
by a rich network of blood vessels in
mammalian lungs that function in gas
exchange; the air sacs are at the end of
the bronchioles.
Axon:
the long extension of a neuron.
Basophils:
the white blood cells that function in allergic
responses. Bioaccumulation:
the process whereby pollutants are taken up, retained
and concentrated in the cells of plants and animals.
Bioluminescence – the production of light by
living organisms.
Biomass:
the
total
dry
weight
of food
at each
level of
the food
pyramid.
Biosphere:
the blanket of living things that surrounds
the substratum of the earth.
Bowman's capsule:
an enlarged cuplike
structure below the
nephron in the human
kidney.
Cells: the fundamental units of living
things
Chemosynthesis:
The process whereby chemical energy is used to make
organic compounds from inorganic compounds. One example
is the oxidation of ammonia to nitrite by nitrifying
bacteria.
Chromatid:
homologous chromosomes
joined to each other at the
centromere; present during
the prophase of mitosis. Cistron: A
length of chromosomal DNA representing the smallest
functional unit of heredity, essentially identical to a
gene. Cofactor: The
nonprotein component of an enzyme; it is required for
catalytic activity.
Cones:
photoreceptor cells
that respond to
bright light and
color and transmit
sharp images. Cristae:
the folds of the inner mitochondrial
membrane. Cytochromes:
molecules that accept and release
electrons in an electron transport
system.
Cytokinesis: is the process in which the cytoplasm of a single eukaryotic cell is divided to form two daughter cells.
Cytosol:
a fluid matrix of
water and dissolved substances such as proteins and
nutrients.
Dermis:
the second
layer of skin.
Diastole:
a relaxation event of
either the atria or ventricles.
Diencephalon:
connects the
cerebrum to the
brain stem.
Diploid: Having a
full set of genetic material consisting of paired
chromosomes. One of each pair of chromosomes comes from
each parent.
Diffusion: the net movement of substances from an area of higher concentration to an area of lower concentration.
Disaccharide:
a carbohydrate consisting of
two linked sugar molecules.
Double Helix: term used to describe the structure of DNA.
Ectoderm:
one of three germ layers
that develops into the skin
and nervous system.
Effluent:
Industrial or urban waste discharged into the
environment.
Electrophoresis:
A method of separating large molecules-such as DNA
fragments or proteins-from a mixture of similar
molecules.
Endoderm:
one of three germ layers that develops into
the gastrointestinal tract.
Endolymph: is the fluid contained in the membranous labyrinth of the inner ear. It is also called Scarpa's fluid, after Antonio Scarpa.
Entropy:
the degree of disorder or randomness of a system.
Enzyme: A protein
that acts as a catalyst, speeding the rate at which a
biochemical reaction proceeds but not altering the
direction or nature of the reaction. All cellular
metabolism is controlled by enzymes.
Eosinophils:
white blood cells whose functions are
uncertain.
Epithelial tissue
acts as a covering and lining on the outside surfaces of
the body and lines the internal organs or secretes
hormones or other products.
Erythrocytes:
the red blood cells; disk-shaped cells
produced in the bone marrow that have no
nucleus; their cytoplasm is filled with
hemoglobin to transport oxygen.
Eubacteria:
modern bacteria
Eutrophication:
Enrichment of a water body with nutrients, resulting
in excessive growth of phytoplankton seaweeds, or
vascular plants, and often depletion of oxygen.
Exon: A segment of
a gene that contains instructions for making a protein.
In many genes the exons are separated by "intervening"
segments of DNA, known as introns, which do not code for
proteins; these introns are removed by splicing to
produce messenger RNA.
Flagella:
structure
that protrudes from the cell
membrane and makes wavelike
movements. Classified by
length and number per cell,
flagella are long and few. A
single flagellum propels
sperm. Structurally flagella
consists of microtubules
arranged in a "9 + 2" array.
Gametangium:
A structure that
contains gametes or in which
gametes are formed.
Ganglia:
clusters
of cell bodies in the peripheral nervous
system. Genome: The full
set of genes present in a cell or virus; all the genetic
material in an organism; a haploid set of genes in a
cell.
Glomerulus: a ball of
capillaries that comprises Bowman's
capsule in the human kidney.
Glucagon:
a hormone produced in the pancreas that
stimulates the breakdown of glycogen to
glucose in the liver.
Glycogen:
A highly branched
polysaccharide containing glucose, which
is used to store carbon and energy.
Glycolysis:
the subdivision of cellular respiration in which glucose
molecules are broken down to form pyruvic acid
molecules.
Gross (macroscopic)
anatomy: the
study of body parts visible to the naked
eye.
Guanine: A
purine derivative, 2-amino-6-oxypurine, found in
nucleosides, nucleotides, and nucleic acids.
Halophile:
A microorganism that requires high
levels of sodium chloride for growth.
Haploid: A cell with
half the usual number of chromosomes, or only on
chromosome set. Sex cells are haploid. Hapten: a
molecule not immunogenic by itself but that, when
coupled to a macromolecular carrier, can elicit
antibodies directed against itself. Helicases:
Enzymes that use ATP energy to unwind DNA ahead of the
replication fork.
Hemopoiesis:
the
process that produces the formed
elements of the blood and takes place in
the red bone marrow of long bones.
Hemostasis:
the stoppage of bleeding through vascular spasm,
platelet plug, or coagulation.
Isotope: One of two or more atoms that have the same atomic number (the same number of protons) but a different number of neutrons.
Histology: the study of tissues at the microscopic level.
Histones:
nuclear proteins that coil DNA molecules
Holdfast:
A structure produced
by some bacteria and
algae that attaches
the cell to a solid
object.
Holoenzyme: A
complete enzyme consisting of the apoenzyme plus a
cofactor. Homologies:
Similarities in DNA
or protein sequences between individuals
of the same species or among different
species.
Homeostasis:
the process in which the internal
environment exists at a steady-state
equilibrium despite changes in the external
environment.
Hypodermis:
the layer
between the
dermis and the
underlying
tissues and
organs.
Hypha:
The
unit of structure of
most fungi and some
bacteria; a tubular
filament.
Hypoxic: Having a
low oxygen level.
Inducer: A small molecule
that stimulates the synthesis of an inducible
enzyme.
Insertion:
the
muscle end that attaches to the moving
structure.
Isogenic: Of the same genotype.
Integrator:
a control center (often the brain).
Intron: A
noncoding intervening sequence in a split or interrupted
gene, which codes for RNA that is missing from the final
RNA product.
Karyotype:
A photomicrograph of
an individual's
chromosomes arranged
in a standard format
showing the number,
size, and shape of
each chromosome
type.
Limbic System:
a
network of neurons that
extends over a wide range of
areas of the brain. Imposes
an emotional aspect to
behaviors, experiences, and
memories. Lipids:
a class of substances that are
insoluble in water (and other polar solvents) but
are soluble in nonpolar substances (like ether or
chloroform). Liposome: A
spherical particle formed by a lipid bilayer enclosing
an aqueous solution. It may be use to administer
chemotherapeutic agents or in diagnostic testing.
Lymph:
a watery fluid derived from plasma that
seeps out of the blood system
capillaries and mingles with the cells.
Lymphocytes: white blood cells (leukocytes) that provide an immune response that attacks specific kinds of nonself cells and foreign substances.
Lysis: Breaking
apart of cells.
Lysogeny: The state
in which a phage genome remains within the baterial host
cell after infection and reproduces along with it rather
than taking control of the host and destroying it.
Macromolecule: A very large molecule, such as a polymer or protein, consisting of many smaller structural units linked together
Macronucleus:
The larger of the two
nuclei in ciliate protozoa. It is
normally polyploid and directs the
routine activities of the cell.
Macrophage (mak_ro-føaj) The name for a large mononuclear phagocytic cell, present in blood, lymph, and other tissues. Macrophages are derived from monocytes. They phagocytose and destroy pathogens; some macrophages also activate B cells and T cells.
Melatonin: a hormone
that helps regulate the biological clock
(sleep-wake cycles).
Mesenchyme: or mesenchymal connective tissue, is an example of reticular connective tissue, a type of loose connective tissue, which is derived from all three germ layers and located within the embryo.
Mesoderm:
one of three germ layers that develops to become the
muscles and other internal organs
Metabolism:
the set of chemical
reactions that happen in
living organisms to
maintain life. These
processes allow
organisms to grow and
reproduce, maintain
their structures, and
respond to their
environments. Metabolism
is usually divided into
two categories.
Catabolism breaks down
organic matter, for
example to harvest
energy in cellular
respiration. Anabolism
uses energy to construct
components of cells such
as proteins and nucleic
acids.
Metastasis:
The transfer of a disease like cancer
from one organ to another not directly connected
with it.
Metamorphosis:
is a biological process by which an
animal physically develops after birth
or hatching, involving a conspicuous and
relatively abrupt change in the animal's
body structure through cell growth and
differentiation.
Microbiology:
The study of
organisms that are usually too small to be
seen with the naked eye. Special techniques
are required to isolate and grow them. Monera:
the kingdom that includes the bacteria
and the cyanobacteria; prokaryotic
organisms.
Monophyletic: descended from a common ancestor or stem cell.
Monosaccharide:
the simplest kind of carbohydrate consisting of a single
sugar molecule.
Mycoplasma: is a genus of bacteria which lack a cell wall. Without a cell wall, they are unaffected by many common antibiotics such as penicillin or other beta-lactam antibiotics that target cell wall synthesis.
Mycosis:
Any disease caused by a fungus.
Nephrons:
filtering units
that number over a million in the
kidneys.
Phagocytes:
white
blood cells that
wander throughout
the body attacking
bacteria and other
foreign invaders.
Phenotype: The
outward physical characteristics of an organism.
Pluripotency: in the broad sense refers to "having more than one potential outcome." In biological systems, this can refer either to cells or to biological compounds. From the Latin pluri=many, potent=power, capacity. A pluripotent cell can create all cell types except for extra embryonic tissue, unlike a totipotent cell, (tot=all), which can produce every cell type including extra embryonic tissue.
Pneumothorax: (a term for collapsed lung) occurs when air leaks into the space between your lungs and chest wall, creating pressure against the lung.
Polymerase:
an enzyme that acts like a molecular
assembly line to build new strands of
DNA.
Polypeptide:
A molecule made up of a string of amino acids. A
protein is an example of a polypeptide.
Proteins: The active molecules in all cells.
Proteins control biochemical reactions and determine
the physical structure of organisms.
Remodeling: the process of creating new bone and removing old bone.
Ribosome:
The small cellular structure in which
RNA translates the genetic code into
proteins.
Rods: photoreceptors that are most sensitive to light and more numerous than cones. The provide vision in dim light and are more capable of detecting movement.
Saprophyte:
An organism that takes up
nonliving organic nutrients in dissolved
form and usually grows on decomposing
organic matter.
Septate: Divided
by a septum or cross wall; also with
more or less regular occurring cross
walls.
Sheath:
A hollow tubelike structure surrounding a chain of
cells and present in several genera of bacteria.
Somatic cells: Any cell in the body except
sex cells.
Spirillum:
a
rigid, spiral-shaped
bacterium Strain: A
population of organisms that descends
from a single organism or pure culture
isolate.
Symbiosome: The
final nitrogen-fixing form of Rhizobium
that is active within root nodule cells.
Synapse (synaptic
cleft): a gap
that separates the neuron from a muscle cell
or another neuron. Systole:
a
contraction event of either the atria or
ventricles.
Transcription: The
process by which DNA passes genetic information to RNA.
Transcription is the first step in producing proteins.
Uracil:
A base; one of the molecular components of RNA.
Bonds only with adenine (U-A).
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