ch 7, 8 and 9 26 of 51 Activity: Regulation: Negative and Positive Feedback Click here to complete this activity. Then answer the questions. Part A Which of these is an example of negative feedback? ANSWER: As a blood clot begins to form, the process of its formation gets faster and faster. After you eat, glucagon stimulates an increase in blood sugar levels. After you eat, insulin stimulates the lowering of blood sugar levels. The digestive enzyme pepsinogen is converted to pepsin by the action of hydrochloric acid; pepsin itself can then convert pepsinogen into pepsin. Once labor begins, contractions increase in frequency and intensity. Activity: How Enzymes Work Click here to complete this activity. Then answer the questions. Part A In general, enzymes are what kinds of molecules? 6/13/2019, 11:24 AM ch 7, 8 and 9 27 of 51 ANSWER: carbohydrates minerals lipids nucleic acids proteins Part B Enzymes work by _____. ANSWER: decreasing the potential energy difference between reactant and product adding energy to a reaction increasing the potential energy difference between reactant and product reducing EA adding a phosphate group to a reactant Part C An enzyme _____. ANSWER: can bind to nearly any molecule is a inorganic catalyst is an organic catalyst increases the EA of a reaction is a source of energy for endergonic reactions Part D What name is given to the reactants in an enzymatically catalyzed reaction? ANSWER: 6/13/2019, 11:24 AM ch 7, 8 and 9 28 of 51 reactors products active sites EA substrate Part E As a result of its involvement in a reaction, an enzyme _____. ANSWER: loses a phosphate group is unchanged is used up loses energy permanently alters its shape. Part F What is the correct label for "A"? ANSWER: enzyme energy ATP uphill substrate energy energy of activation 6/13/2019, 11:24 AM