5 Written questions
5 Matching questions
- passive transport
- induced fit
- concentration gradient
- a The diffusion of a substance across a biological membrane, without any input of energy.
- b A nonprotein molecule or ion that is required for the proper functioning of an enzyme. See also coenzyme.
- c (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.
- d 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.
- e An increase or decrease in the density of a chemical substance in an area. Cells often maintain concentration gradients of ions across their membranes. When a gradient exists, substances tend to move from where they are more concentrated to where they are less concentrated.
5 Multiple choice questions
- 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).
- Cellular "drinking"; a type of endocytosis in which the cell takes fluid and dissolved solutes into small membranous vesicles.
- Method by which organisms regulate solute concentrations and balance the gain and loss of water.
- The energy that matter possesses because of its location or arrangement. Water behind a dam and chemical bonds possess potential energy.
- A method of metabolic control in which a product of a metabolic pathway acts as an inhibitor of an enzyme within that pathway.
5 True/False questions
tonicity → A measure of disorder. One form of disorder is heat, which is random molecular motion.
second law of thermodynamics → The principle of conservation of energy. Energy can be transferred and transformed, but it cannot be created or destroyed.
adenosine triphosphate (ATP) → Main energy source for cells.
selective permeability → 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).
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.