Flashcards in Biology Part. 1 Deck (21):
The part of an enzyme molecule where a substrate molecule attaches (by means of weak chemical bonds); typically, a pocket or groove on the enzyme's surface.
The movement of a substance across a biological membrane against its concentration gradient, aided by specific transport proteins and requiring input of energy (often as ATP).
Main energy source for cells.
A transport protein in the plasma membrane of some plant or animal cells that facilitates the diffusion of water across the membrane (osmosis).
The aerobic harvesting of energy from food molecules; the energy- releasing chemical breakdown of food molecules, such as glucose, and the storage of potential energy in a form that cells can use to perform work; involves glycolysis, the citric acid cycle, and oxidative phosphorylation (the electron transport chain and chemiosmosis).
Energy available in molecules for release in a chemical reaction; a form of potential energy.
An organic molecule serving as a cofactor. Most vitamins function as coenzymes in important metabolic reactions.
A nonprotein molecule or ion that is required for the proper functioning of an enzyme. See also coenzyme.
A substance that reduces the activity of an enzyme by binding to the enzyme's active site in place of the substrate. A competitive inhibitor's structure mimics that of the enzyme's substrate.
An increase or decrease in the density of a chemical substance in an area.
The spontaneous tendency of a substance to move down its concentration gradient from where it is more concentrated to where it is less concentrated.
An energy-requiring chemical reaction, which yields products with more potential energy than the reactants. The amount of energy stored in the products equals the difference between the potential energy in the reactants and that in the products.
Cellular uptake of molecules or particles via formation of new vesicles from the plasma membrane
The capacity to perform work, or to rearrange matter.
In cellular metabolism, the use of energy released from an exergonic reaction to drive an endergonic reaction.
A measure of disorder. One form of disorder is heat, which is random molecular motion.
A protein (or RNA molecule) that serves as a biological catalyst, changing the rate of a chemical reaction without itself being changed into a different molecule in the process.
An energy-releasing chemical reaction in which the reactants contain more potential energy than the products. The reaction releases an amount of energy equal to the difference in potential energy between the reactants and the products.
The movement of materials out of the cytoplasm of a cell by the fusion of vesicles with the plasma membrane
The passage of a substance through a specific transport protein across a biological membrane down its concentration gradient.