BIO - TERMS - ACID Flashcards
acid dissociation constant
The dissociation constant (Ka) of an acid, describing its dissociation into its conjugate base and a proton.
acid ionization constant (Ka)
The equilibrium constant for the ionization reaction of a weak acid; used to compare the relative strengths of weak acids.
acid-fast stain
A differential stain used to identify bacteria that are not decolorized by acid-alcohol.
acid–base reaction (neutralization reaction)
A reaction in which an acid reacts with a base and the two neutralize each other, producing water.
acid–base titration
A laboratory procedure in which a basic (or acidic) solution of unknown concentration reacts with an acidic (or basic) solution of known concentration in order to determine the concentration of the unknown.
acidic solution
A solution containing an acid that creates additional H3O+ ions, causing 3H3O+4 to increase.
algin
A sodium salt of mannuronic acid (C6H8O6); found in brown algae.
ampholyte
A substance that can act as either a base or an acid.
anaplerotic reaction
An enzyme-catalyzed reaction that can replenish the supply of intermediates in the citric acid cycle.
Anaplerotic reactions
Reactions that result in the net production of a tricarboxylic acid (TCA) cycle intermediate.
Annealing
Formation of a double strand from two complementary nucleic acid strands.
Antioxidant defense
The whole biochemical system of the cell that decomposes reactive oxygen and reactive nitrogen species. It consists of enzymes including superoxide dismutase and peroxidases and low molecular mass molecules such as ascorbic acid and glutathione.
Arrhenius definitions (of acids and bases)
According to these definitions, an acid is defined as a substance that produces H+ ions in aqueous solution, and a base is defined as a substance that produces OH- ions in aqueous solution.
Arsenite
An inhibitor of pyruvate dehydrogenase that binds to dihydrolipoic acid.
autoionization
The process by which water acts as an acid and a base with itself.
Base analogs
Unnatural purine or pyrimidine bases that differ slightly from the normal bases and that can be incorporated into nucleic acids. They are often mutagenic.
Base stacking
The noncovalent interaction between successive bases within a nucleic acid strand.
bi-orientation
The attachment of sister chromatids to opposite poles of the mitotic spindle, so that they move to opposite ends of the cell when they separate in anaphase. binding site Region on the surface of one molecule (usually a protein or nucleic acid) that can interact with another molecule through noncovalent bonding.
binary acid
An acid composed of hydrogen and a nonmetal.
Brønsted–Lowry base
A substance that accepts H1 from an acid.
Brønsted–Lowry definitions (of acids and bases)
According to these definitions, an acid is defined as a proton (H+ ion) donor and a base is defined as a proton acceptor.
buffer capacity
The amount of acid or base that can be added to a buffer without causing a large change in pH.
C6-C1-phenolics
Heterogenous collection of simple phenolic compounds derived from intermediates of the shikimate pathway. Examples include gallic acid and salicylic acid.
Cannizzaro reaction
The disproportionation reaction of an aldehyde on treatment with base to yield an alcohol and a carboxylic acid.
Carboxylic acid derivative
A compound in which an acyl group is bonded to an electronegative atom or substituent that can act as a leaving group in a substitution reaction. Esters, amides, and acid halides are examples.
CD22
An inhibitory receptor on B cells that binds sialic acid-modified glycoproteins commonly found on mammalian cells and contains an ITIM motif in its cytoplasmic tail.
CD44
Also known as phagocytic glycoprotein-1 (Pgp1), CD44 is a cellsurface glycoprotein expressed by naive lymphocytes and upregulated on activated T cells. It is a receptor for hyaluronic acid and functions in cell–cell and cell–extracellular matrix adhesion. High expression of CD44 is used as a marker for effector and memory T cells.
Cholestyramine
A bile acid-binding resin that is used as a cholesterol-lowering agent.
coliforms
Aerobic or facultatively anaerobic, gram-negative, non– endospore-forming, rod-shaped bacteria that ferment lactose with acid and gas formation within 48 hours at 35°C.
common ion effect
The tendency for a common ion to decrease the solubility of an ionic compound or to decrease the ionization of a weak acid or weak base.
contact process
An industrial method for the production of sulfuric acid.
Curtius rearrangement
The conversion of an acid chloride into an amine by reaction with azide ion, followed by heating with water.
denaturing
The process by which a protein loses its complex tertiary and quaternary structure by heat, acids, salts, or solvents.
Diazotization
The conversion of a primary amine, RNH2, into a diazonium ion, RN2+, by treatment with nitrous acid.
diprotic acid
An acid that contains two ionizable protons.
Enterohepatic circulation
The cycling of bile acids (and other compounds) through liver and intestine.
equivalence point
The point in the titration at which the added solute completely reacts with the solute present in the solution; for acid–base titrations, the point in the titration when the number of moles of base is stoichiometrically equal to the number of moles of acid.
extremophile
A microorganism that lives in environmental extremes of temperature, acidity, alkalinity, salinity, or pressure.
Fischer esterification reaction
The acid-catalyzed nucleophilic acyl substitution reaction of a carboxylic acid with an alcohol to yield an ester. Fischer projection uses a cross to represent the chirality center. The horizontal arms of the cross represent bonds coming out of the plane of the page, and the vertical arms of the cross represent bonds going back into the plane of the page.
GABAergic
Describing neurons or synapses that produce and release gamma-aminobutyric acid.
Hell–Volhard–Zelinskii (HVZ) reaction
The reaction of a carboxylic acid with Br2 and phosphorus to give an a-bromo carboxylic acid.
Heteroduplex
A double-stranded nucleic acid containing one or more mismatched (noncomplementary) base pairs.
heterolactic
Describing an organism that produces lactic acid and other acids or alcohols as end-products of fermentation; e.g., Escherichia.
homolactic
Describing an organism that produces only lactic acid from fermentation; e.g., Streptococcus.
Hydration
Addition of water to a molecule, such as occurs when alkenes are treated with aqueous sulfuric acid to give alcohols.
inorganic
Chemical substance that is not organic; e.g., water, acids, bases.