Biochemistry 1430 chapter 8 (with 100% Error-free Solutions)

enzyme concentration correct answers the more enzyme present, the faster substrate reacts pH correct answers enzymes have optimum pHs above and below which the rate decreases Pepsin is correct answers a proteolytic enzyme found in the Stomach Chymotrypsin is a correct answers proteolytic enzyme found in the intestine Temperature correct answers enzymes have an optimum temperature, above which they begin to denature An enzyme, tyrosinase, is key in the production of melanin (the molecule that produces the black color in the fur). correct answers Tyrosinase in Siamese cats is mutated and this mutated enzyme is more temperature-sensitive than the tyrosinase in other animals so the enzyme is less active at higher temperatures. Therefore, the cat's extremities are darker, as these body parts tend to be slightly cooler. This molecular mechanism suggests that Siamese cats living in cooler regions should have a darker pattern than those living in warmer areas. In fact, this is true. Enzyme activity can also be affected by inhibitors correct answers and those inhibitors are incredibly important therapeutically Three ways to inhibit an enzyme correct answers Competitive Uncompetitive Non-competitive Each inhibits enzyme function in a mechanistically different way and each has unique effects on Vmax and/or Km COMPETITIVE INHIBITION correct answers The inhibitor competes for the binding (active) site and reduces the number of sites available for binding substrate. Can be overcome by increasing the concentration of substrate [S]. Sulfonamide drugs correct answers are structurally similar to para-aminobenzoic acid (PABA), and their antibacterial activity is due to their ability to interfere with the conversion of PABA to folate (remember the section on vitamins) by inhibiting the enzyme dihydropteroate synthetase. Thus, bacterial growth is limited through folate deficiency without effect on human cells which do not contain this enzyme and obtain folate through other sources. Note that with a competitive inhibitor correct answers the Vmax does not change. If you add enough substrate, you can get the enzyme to work at correct answers It's maximum rate