5 Written Questions
5 Matching Questions
- receptor-mediated endocytosis
- adenosine triphosphate (ATP)
- concentration gradient
- passive transport
- a The diffusion of a substance across a biological membrane, without any input of energy.
- b 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.
- c Main energy source for cells.
- d The spontaneous tendency of a substance to move down its concentration gradient from where it is more concentrated to where it is less concentrated.
- e 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.
5 Multiple Choice Questions
- The energy of motion; the energy of a mass of matter that is moving. Moving matter does work by imparting motion to other matter.
- (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 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 lose water.
- Referring to a solution that, when surrounding a cell, will cause the cell to take up water.
5 True/False Questions
chemical energy → The energy of motion; the energy of a mass of matter that is moving. Moving matter does work by imparting motion to other matter.
potential energy → Energy available in molecules for release in a chemical reaction; a form of potential energy.
coenzyme → An organic molecule serving as a cofactor. Most vitamins function as coenzymes in important metabolic reactions.
heat → The capacity to perform work, or to rearrange matter.
osmosis → The diffusion of water across a selectively permeable membrane.