5 Written questions
5 Matching questions
- potential energy
- concentration gradient
- a 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.
- b Cellular "drinking"; a type of endocytosis in which the cell takes fluid and dissolved solutes into small membranous vesicles.
- c The capacity to perform work, or to rearrange matter.
- d The ability of a solution surrounding a cell to cause that cell to gain or lose water.
- e The energy that matter possesses because of its location or arrangement. Water behind a dam and chemical bonds possess potential energy.
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).
- 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.
- The principle of conservation of energy. Energy can be transferred and transformed, but it cannot be created or destroyed.
- A transport protein in the plasma membrane of some plant or animal cells that facilitates the diffusion of water across the membrane (osmosis).
- 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 True/False questions
osmoregulation → Method by which organisms regulate solute concentrations and balance the gain and loss of water.
heat → 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.
exergonic 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.
noncompetitive inhibitor → 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.
coenzyme → 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.