5 Written questions
5 Matching questions
- endergonic reaction
- fluid mosaic
- a A measure of disorder. One form of disorder is heat, which is random molecular motion.
- b The spontaneous tendency of a substance to move down its concentration gradient from where it is more concentrated to where it is less concentrated.
- c 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.
- d 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.
- e A description of membrane structure, depicting a cellular membrane as a mosaic of diverse protein molecules embedded in a fluid bilayer made of phospholipid molecules.
5 Multiple choice questions
- 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.
- The diffusion of water across a selectively permeable membrane.
- 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 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.
- Referring to a solution that, when surrounding a cell, will cause the cell to take up water.
5 True/False questions
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.
energy → The capacity to perform work, or to rearrange matter.
thermodynamics → The movement of materials out of the cytoplasm of a cell by the fusion of vesicles with the plasma membrane.
active transport → 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 respiration → 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).