5 Written questions
5 Matching questions
- isotonic solution
- potential energy
- a An organic molecule serving as a cofactor. Most vitamins function as coenzymes in important metabolic reactions.
- b Thermal energy; the amount of energy associated with the movement of the atoms and molecules in a body of matter. Heat is energy in its most random form.
- c The energy that matter possesses because of its location or arrangement. Water behind a dam and chemical bonds possess potential energy.
- d A solution having the same solute concentration as another solution, thus having no effect on passage of water in or out of the cell.
- e Cellular uptake of molecules or particles via formation of new vesicles from the plasma membrane.
5 Multiple choice questions
- (1) A specific substance (reactant) on which an enzyme acts. Each enzyme recognizes only the specific substrate or substrates of the reaction it catalyzes. (2) A surface in or on which an organism lives.
- 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).
- A nonprotein molecule or ion that is required for the proper functioning of an enzyme. See also coenzyme.
- The principle of conservation of energy. Energy can be transferred and transformed, but it cannot be created or destroyed.
- Referring to a solution that, when surrounding a cell, will cause the cell to take up water.
5 True/False questions
receptor-mediated endocytosis → Cellular "drinking"; a type of endocytosis in which the cell takes fluid and dissolved solutes into small membranous vesicles.
induced fit → The change in shape of the active site of an enzyme, induced by entry of the substrate so that it binds more snugly to the substrate.
endergonic reaction → 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.
diffusion → The spontaneous tendency of a substance to move down its concentration gradient from where it is more concentrated to where it is less concentrated.
active site → 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.