BIO - TERMS - FREQUENCY > 1 PT 3 Flashcards
action spectrum
A graph for which relative light sensitivity of a physiological response is plotted against the wavelength of light. // A plot of the efficiency of light at promoting a light-dependent process such as photosynthesis as a function of wavelength.
ADP (adenosine 5′-diphosphate // adenosine diphosphate)
A ribonucleoside 5’-diphosphate serving as phosphate group acceptor in the cell energy cycle. // Nucleotide produced by hydrolysis of the terminal phosphate of ATP. Regenerates ATP when phosphorylated by an energy-generating process such as oxidative phosphorylation.
alkane
A hydrocarbon containing only single bonds. // A class of compounds of carbon and hydrogen that contains only single bonds.
amine
A class of compounds containing one or more organic substituents bonded to a nitrogen atom, RNH2, R2NH, or R3N. // An organic compound containing nitrogen and derived from ammonia by replacing one or more hydrogen atoms on ammonia with an alkyl group.
anaphylaxis
A hypersensitivity reaction involving IgE antibodies, mast cells, and basophils. // A rapid-onset and systemic allergic reaction to antigen, for example to insect venom injected directly into the bloodstream, or to foods such as peanuts. Severe systemic reactions can be potentially fatal due to circulatory collapse and suffocation from tracheal swelling. It usually results from antigens binding to IgE bound by Fcε receptors on mast cells, leading to systemic release of inflammatory mediators.
antigen–antibody complex
A noncovalent aggregate between antigen and antibody. // The combination of an antigen with the antibody that is specific for it; the basis of immune protection and many diagnostic tests.
aqueous humor
The fluid between the cornea and the lens of the eye. // A clear watery fluid formed by the ciliary process within the eye and circulates within the anterior cavity of the eye and then drains through the circular canal called the scleral venous sinus.
Attenuated
An infection in which normally severe symptoms or pathology are mild or inconsequential; a state of reduced virulence. (Chapter 1) // Having mild or inconsequential instead of normally severe symptoms or pathology as an outcome of infection; having a state of reduced virulence. (Chapter 5)
autotroph
An organism that uses carbon dioxide (CO2) as its principal carbon source; chemoautotroph, photoautotroph. // An organism that can synthesize its own complex molecules from very simple carbon and nitrogen sources, such as carbon dioxide and ammonia.
Base pairing
The specific interaction between two bases in opposite strands of a double-stranded nucleic acid. // Complexation of the complementary pair of polynucleotide chains of nucleic acids through hydrogen bonds between complementary purine and pyrimidine bases adenine (A) with thymine (T) or uracil (U), cytosine (C) with guanine (G).
bioremediation
The use of microbes to remove an environmental pollutant. // The use of living organisms to remove metals and xenobiotics from the environment.
brain stem
Brain region composed of the midbrain, pons, and medulla oblongata. // The diencephalon, midbrain, pons, and medulla. (Some anatomists exclude the diencephalon.)
capsule
A collection of axons that connect the cerebrum with the brain stem. // An outer, viscous covering on some bacteria composed of a polysaccharide or polypeptide.
carrier
Organism (usually refers to humans) that harbors pathogens and transmits them to others. // An individual who carries a recessive allele that is not expressed (that is, is obscured by a dominant allele).
cerebrospinal fluid (CSF)
In the central nervous system, the fluid produced by the choroid plexus that flows through the ventricular system to the subarachnoid space. // A clear, colorless fluid that circulates in the ventricles, subarachnoid space, and central canal to protect and support the brain and spinal cord.
chiasma (plural chiasmata)
X-shaped connection visible between paired homologous chromosomes during meiosis. Represents a site of chromosomal crossing-over, a form of genetic recombination. // A visible change of partners in two of a group of four chromatids during the first meiotic prophase. In the diplotene stage of meiosis, the four chromatids of a bivalent are associated in pairs, but in such a way that one part of two chromatids is exchanged. This point of “change of partner” is the chiasma.
chromatid
(krō′mă-tid) One of the two strands of a chromosome joined by a centromere. // In mitosis or meiosis, one of the two identical strands resulting from self-duplication of a chromosome.
co-receptor
In immunology: an accessory receptor on B cells or T cells that does not bind antigen but binds to a co-stimulatory signal and helps activate the lymphocyte, by helping to activate an intracellular signaling pathway. // Cell-surface protein that increases the sensitivity of a receptor to its ligand by binding to associated ligands and participating in signaling. The antigen receptors on T cells and B cells act in conjunction with co-receptors, which are either CD4 or CD8 on T cells, and a co-receptor complex of three proteins, one of which is the complement receptor CR2, on B cells.
Complementation test (trans test)
Test to determine whether two mutations that produce similar phenotypes are in the same or different genes. // Introduction of two recessive mutations into the same cell to determine whether they are alleles of the same gene, that is, whether they affect the same genetic function. If the mutations are allelic, the genotype m1 +/+ m2 will exhibit a mutant phenotype, whereas if they are nonallelic, it will exhibit the wild phenotype.
conjunctiva
The membrane that folds back from the eyelids and attaches to the sclera of the eye. // (kon-jŭnk-tı̄′vă) Epithelial layer covering the anterior surface of the sclera and the posterior surface of the eyelids.
coordination number (secondary valence)
The number of molecules or ions directly bound to the metal atom in a complex ion.
Cyclooxygenase
The key enzyme for the synthesis of prostaglandins, prostacyclin, and thromboxane. // An enzyme that is important in the production of a group of powerful biochemical compounds called prostanoids, which include such compounds as prostaglandins, prostacyclin, and thromboxane.
Deletion mutation
Loss of one or more bases in a nucleic acid. (Chapter 3) // A mutation resulting from the deletion of one or more nucleotides from a gene or chromosome.
Diastereomers
Geometric isomers. // Non–mirror-image stereoisomers; diastereomers have the same coniguration at one or more chirality centers but differ at other chirality centers.
Dissociation (Ds)
The separation of a compound into positive and negative ions in solution. See also ionization. // A transposable element in maize, originally detected as an agent that mediates chromosome breakage in response to the effect of Activator (Ac), another transposable element.
DNA topoisomerase (topoisomerase)
An enzyme that catalyzes the introduction or removal of supercoils from DNA. // Enzyme that binds to DNA and reversibly breaks a phosphodiester bond in one or both strands. Topoisomerase I creates transient singlestrand breaks, allowing the double helix to swivel and relieving superhelical tension. Topoisomerase II creates transient doublestrand breaks, allowing one double helix to pass through another and thus resolving tangles.
eclipse period
The time during viral multiplication when complete, infective virions are not present. // The phase of viral infection during which the viral nucleic acid is uncoated from its protective shell and no infectious virus can be detected inside cells. (Chapter 2)
electrolyte
A substance that dissolves in water to form solutions that conduct electricity. // (ē-lek′trō-lı̄t) Chemical that dissociates when added to water and can conduct an electrical current; includes salts, bases, and acids.
Embryo
An organism in the early stages of development; in humans, the first two months in the uterus. // (em′brē-ō) Organism in the early stages of development; in humans, the embryonic stage extends from the third to the eighth week of development.
Enzyme-substrate complex
Enzyme with a noncovalently bound substrate. // A temporary union of an enzyme and its substrate.
ester linkage
Bonding between fatty acids and glycerol in bacterial and eukaryotic phospholipids: O C O C // The bonds that form between a carboxylic acid and an alcohol to form an ester, such as those in triglycerides.
FAD (flavin adenine dinucleotide)
The coenzyme of some oxidation-reduction enzymes; contains riboflavin. // Flavin adenine dinucleotide; a coenzyme that functions in the removal and transfer of hydrogen ions (H1) and electrons from substrate molecules.
filtration
The passage of a liquid or gas through a screenlike material; a 0.45-μm filter removes most bacteria. // A procedure used to separate a mixture composed of an insoluble solid and a liquid by pouring the mixture through filter paper or some other porous membrane or layer.
FMN (flavin mononucleotide)
Riboflavin phosphate, a coenzyme of certain oxidationreduction enzymes. // Flavin mononucleotide; a coenzyme that functions in the transfer of electrons in the electron transport chain.
G1-Cdk
Cyclin–Cdk complex formed in vertebrate cells by a G1-cyclin and the corresponding cyclin-dependent kinase (Cdk).
Gap gene
A gene that controls the formation of adjacent segments in the body of Drosophila. // In Drosophila development, a gene that is expressed in specific broad regions along the anteroposterior axis of the early embryo, and which helps designate the main divisions of the insect body.
Germ cell
A reproductive cell capable when mature of being fertilized and reproducing an entire organism (cf. Somatic cell). // A cell in the germ line of an organism, which includes the haploid gametes and their specified diploid precursor cells. Germ cells contribute to the formation of a new generation of organisms and are distinct from somatic cells, which form the body and leave no descendants.
glycogenesis
(glı̄′kō-jen′ĕ-sis) Formation of glycogen from glucose. // The process of converting glucose to glycogen.
Gram positive // gram-positive bacteria
Bacteria that retain the crystal violet color after decolorizing by alcohol; they stain dark purple. // Description for bacteria that stain positive with Gram stain due to a thick layer of peptidoglycan cell wall outside their inner (plasma) membrane.
hair cell
Specialized sensory cell in the inner ear. // An auditory cell that transduces sound into a change in membrane potential or a vestibular cell that transduces head movements into a change in membrane potential.
