BIO - TERMS - FREQUENCY > 1 PT 7 Flashcards
absolute refractory period
Time period when an excitable cell cannot be restimulated to respond. // The period of time, measured from the onset of an action potential, during which another action potential cannot be triggered.
adaptive immunity
Immunity to infection conferred by an adaptive immune response. // The ability, obtained during the life of the individual, to produce specific antibodies and T cells.
affinity maturation
Progressive increase in the affinity of antibodies for the immunizing antigen with the passage of time after immunization. // The increase in affinity for their specific antigen of the antibodies produced as an adaptive immune response progresses. This phenomenon is particularly prominent in secondary and subsequent immunizations.
allograft
A tissue graft that is not from a genetically identical donor (i.e., not from self or an identical twin). // A transplant of tissue from an allogeneic (genetically nonidentical) donor of the same species. Such grafts are invariably rejected unless the recipient is immunosuppressed.
amphibolic pathway
A pathway that is both anabolic and catabolic. // A metabolic pathway used in both catabolism and anabolism.
angiotensin-converting enzyme (ACE)
An enzyme of angiotensin synthesis; important drug target. // An enzyme in the lung that converts angiotensin I to angiotensin II.
antiserum
A blood-derived fluid containing antibodies. // The fluid component of clotted blood from an immune individual that contains antibodies against the antigen used for immunization. An antiserum contains a mixture of different antibodies that all bind the antigen, but which each have a different structure, their own epitope on the antigen, and their own set of cross-reactions. This heterogeneity makes each antiserum unique.
ascospore
A sexual fungal spore produced in an ascus, formed by the ascomycetes. // One of the spores contained in the ascus of certain fungi such as Neurospora.
Aufbau principle
The rules for determining the electron coniguration of an atom. // The principle that indicates the pattern of orbital filling in an atom.
Avoidance
The capability of a plant to resist stress by minimizing the impacts encountered by the plant. // Mechanisms that prevent a host’s exposure to microbes, such as anatomic barriers or particular behaviors.
beta (β) particle
A medium-energy particle released during beta decay; equivalent to an electron.
Blastula
In animals, an early embryo form that follows the morula stage; typically, a single-layered sheet or ball of cells. // Early stage of an animal embryo, usually consisting of a hollow ball of epithelial cells surrounding a fluid-filled cavity, before gastrulation begins.
C-reactive protein
The most sensitive acute-phase reactant. // An acute-phase protein that binds to phosphocholine, a constituent of the surface C-polysaccharide of the bacterium Streptococcus pneumoniae and of many other bacteria, thus opsonizing them for uptake by phagocytes.
carbon-fixation reaction
Process by which inorganic carbon (as atmospheric CO2) is incorporated into organic molecules. The second stage of photosynthesis. // The reactions, catalyzed by rubisco during photosynthesis or by other carboxylases, in which atmospheric CO2 is initially incorporated (fixed) into an organic compound.
cDNA (complementary DNA)
DNA made in vitro from an mRNA template. // A DNA molecule synthesized in vitro from an RNA template.
chemical energy
Energy stored in the chemical bonds of a molecule. // The energy associated with the relative positions of electrons and nuclei in atoms and molecules.
Chirality center (chiral center)
An atom (usually carbon) that is bonded to four different groups. // An atom with substituents arranged so that the molecule is not superposable on its mirror image.
class
A taxonomic group between phylum and order.
Collagen
A family of fibrous proteins in the extracellular matrix, with a characteristic triple-helical structure. // Fibrous protein rich in glycine and proline that is a major component of the extracellular matrix in animals, conferring tensile strength. Exists in many forms: type I, the most common, is found in skin, tendon, and bone; type II is found in cartilage; type IV is present in basal laminae.
condensation
The phase transition from gas to liquid. // A reaction type in which two compounds are joined with the elimination of water.
Constitutive enzyme
An enzyme that is synthesized continually regardless of growth conditions (cf. Inducible enzyme and Repressible enzyme). // Enzymes required at all times by a cell and present at some constant level; for example, many enzymes of the central metabolic pathways. Sometimes called housekeeping enzymes.
creatine
(krē′-ă-tēn; -tin) Chemical providing muscle cells with energy; present as creatine phosphate. // A metabolite in muscle that forms the energy-rich compound creatine phosphate.
death receptor
Receptors for extracellular ligands; their activation triggers apoptosis. // Transmembrane receptor protein that can signal the cell to undergo apoptosis when it binds its extracellular ligand.
desensitization
The prevention of allergic inflammatory responses. // Universal process by which sensory mechanisms cease to respond after prolonged exposure to the specific stimulus they detect.
dimer
The product that forms from the reaction of two monomers. // A compound having the same percentage composition as another but twice the molecular weight; one formed by polymerization.
DNA fingerprinting
DNA-based methods for the identification of persons in criminal cases. // Analysis of DNA by electrophoresis of restriction enzyme fragments of the DNA.
dorsal
An anatomical reference meaning toward the back. // (dōr′săl) Toward the back. dorsiflexion (dōr-si-flek′shŭn) Movement of the foot whereby the dorsum of the foot is brought closer to the anterior leg region.
effector memory T cells (TEM)
Memory T cells that produce cytokines rapidly upon re-encountering a viral antigen, and are generally present in the circulatory system. (Chapter 4) // Memory lymphocytes that recirculate between blood and peripheral tissues and are specialized for rapid maturation into effector T cells after restimulation with antigen in nonlymphoid tissues.
electron shell
A group of an atom’s electrons with the same principal quantum number. // A region of an atom where electrons orbit the nucleus, corresponding to an energy level.
endorphin
Peptides that activate opiate receptors. // One of many endogenous opioid peptides with actions similar to those of morphine; present in many brain structures, particularly those related to pain.
epidemiology
The science that studies when and where diseases occur and how they are transmitted. // Th e study of the incidence, distribution, and spread of infectious disease in populations with particular regard to identifi - cation and subsequent control. (Chapter 1)
Exonuclease
An enzyme that digests DNA or RNA, beginning at the ends of strands. // Enzymes that hydrolyze only those phosphodiester bonds that are in the terminal positions of a nucleic acid.
fatty liver
Fat infiltration and inflammation of the liver. // A reversible lesion caused by increased hepatic triglyceride synthesis or impaired very-lowdensity lipoprotein (VLDL) formation.
Fitness
Th e degree to which an organism is able to reproduce its environment. (Chapter 10) // The number of offspring left by an individual, often compared with the average of the population or with some other standard, such as the number left by a particular genotype.
fomite
A nonliving object that can spread infection. // Inanimate objects that may be contaminated with microorganisms and become vehicles for transmission. (Chapter 1)
Gametogenesis
The formation of gametes. // (gam′ĕ-tō-jen′ĕ- sis) Formation and development of gametes (sex cells).
gene family
Structurally related genes with a common evolutionary origin. // The set of genes in an organism related in DNA sequence due to their derivation from the same ancestor. gene segments In immunology: short DNA sequences that are joined together during B cell and T cell development to produce the coding sequences for immunoglobulins and T cell receptors, respectively.
glucose transporter (GLUT)
A family of proteins that transport glucose across cell membranes. // Designation for a family of membrane proteins that transport glucose.
goiter
Hypertrophy of the thyroid gland, caused by a deficiency of iodine. // Enlargement of the thyroid gland; seen in some forms of hypothyroidism and hyperthyroidism.
Graves disease
An autoimmune disease leading to hyperthyroidism. // An autoimmune disease in which antibodies against the thyroid-stimulating hormone receptor cause overproduction of thyroid hormone and thus hyperthyroidism.
