5 Written questions
5 Matching questions
- feedback inhibition
- active transport
- 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 A method of metabolic control in which a product of a metabolic pathway acts as an inhibitor of an enzyme within that pathway.
- c 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).
- d The transfer of a phosphate group, usually from ATP, to a molecule. Nearly all cellular work depends on ATP energizing other molecules by phosphorylation.
- e The totality of an organism's chemical reactions.
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.
- A property of biological membranes that allows some substances to cross more easily than others and blocks the passage of other substances altogether.
- A solution having the same solute concentration as another solution, thus having no effect on passage of water in or out of the cell.
- 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.
- An energy-releasing chemical reaction in which the reactants contain more potential energy than the products. The reaction releases an amount of energy equal to the difference in potential energy between the reactants and the products.
5 True/False questions
diffusion → The diffusion of water across a selectively permeable membrane.
osmosis → The diffusion of water across a selectively permeable membrane.
first 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.
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.
phagocytosis → Cellular "eating"; a type of endocytosis whereby a cell engulfs macromolecules, other cells, or particles into its cytoplasm.