Aqa As Level Biology Study Guide Graded A+

What are the three ways a pathogen can damage hosts cells? {Ans: 1) rupturing them to release nutrients inside them 2) breaking down nutrients inside the cell for their own use. This starves and eventually kills the cell. 3) replicating inside the cells and bursting them when they're released}Explain what a non-competitive inhibitor is. {Ans: 1) non-competitive inhibitor molecules bind to the enzyme away from its active site 2) This causes the active site to change shape so the substrate molecules can no longer bind to it. 3) They dont compete with the substrate molecules to bind to the active site because they are a different shape. 4) increasing the concentration wont make any difference - enzyme activity will still be inhibited.}Explain the effect of temperature on enzymes. {Ans: 1) The rise in temperature makes the enzymes molecules vibrate more 2) If the temperature goes above a certain level, this vibration breaks some of the bonds that hold the enzyme in shape 3) The active site changes shape and the enzyme and subtrate no longer fit together 4) At this point, the enzyme in denatured}Explain what order organelles are seperated in ultracentrifugation {Ans: 1) nuclei 2)