5 Written questions
5 Matching questions
- noncompetitive inhibitor
- competitive inhibitor
- active site
- passive transport
- a 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.
- b Cellular uptake of molecules or particles via formation of new vesicles from the plasma membrane.
- c The diffusion of a substance across a biological membrane, without any input of energy.
- d A substance that impedes the activity of an enzyme without entering an active site. By binding elsewhere on the enzyme, a noncompetitive inhibitor changes the shape of the enzyme so that the active site no longer functions.
- e 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.
5 Multiple choice questions
- The transfer of a phosphate group, usually from ATP, to a molecule. Nearly all cellular work depends on ATP energizing other molecules by phosphorylation.
- 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).
- The ability of a solution surrounding a cell to cause that cell to gain or lose water.
- A measure of disorder. One form of disorder is heat, which is random molecular motion.
- A nonprotein molecule or ion that is required for the proper functioning of an enzyme. See also coenzyme.
5 True/False questions
receptor-mediated endocytosis → The movement of specific molecules into a cell by the inward budding of membranous vesicles. The vesicles contain proteins with receptor sites specific to the molecules being taken in.
second law of thermodynamics → The principle whereby every energy conversion reduces the order of the universe, increasing its entropy. Ordered forms of energy are at least partly converted to heat.
first law of thermodynamics → The principle of conservation of energy. Energy can be transferred and transformed, but it cannot be created or destroyed.
exocytosis → Cellular uptake of molecules or particles via formation of new vesicles from the plasma membrane.
feedback inhibition → 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.