NAS Exam 2 Questions with All Correct Answers

NAS Exam 2 Questions with All Correct Answers why is chemical energy needed by cells? - Answer-to maintain homeostasis Define cell respiration - Answer-the mechanism for harvesting energy from fuel molecules; the oxidation of glucose to produce ATP what is the function of the reduced coenzymes? - Answer-They are used to transfer energy to another compound Describe the function of oxidation-reduction reactions in the synthesis of ATP. - AnswerThe reaction that transports energy to reduced coenzymes for synthesis of ATP How are hydrogen atoms involved the redox reactions? - Answer-When redox reactions take place they usually involve the loss of hydrogen atoms. What happens to the energy stored within the newly formed reduced coenzyme? Why is this referred to as phosphorylation? - Answer-Phosphorylation is the addition of a phosphate group to a molecule. Name the four steps in cell respiration - Answer-1. Glycolysis, 2. Formation of acetyl coenzyme A, 3. Krebs cycle, 4. Electron transport chain Why is glycolysis "anaerobic" while the other three pathways are "aerobic." - AnswerBecause oxygen is not required to generate ATP during glycolysis. Where does glycolysis occur? - Answer-in the cytosol Two ATP molecules are used to split a glucose molecule. ATP is actually gained through glycolysis, however. How much ATP is produced by this process and what is the net gain? - Answer-4 ATP gross, 2 net How many reduced coenzyme molecules are produced by glycolysis? - Answer-2 Two molecules are produced by glycolysis. Identify them. - Answer-Pyruvic acid & NADH + H+ Describe the conditions that result in lactic acid production - Answer-anaerobic, not enough oxygen Where within the cell will further oxidation of pyruvic acid molecules occur - Answer-In the matrix of the mitochondria Describe the two steps that result in the formation of acetyl Co-enzyme A. - Answer-1. A molecule of CO2 is removed from the pyruvic acid through decarboxylation. Pyruvic acid is oxidized. 2. The acetyl group binds with Co-enzyme A to form acetyl CoA. Each glucose molecule results in the production of 6 CO2 molecules as a waste gas. How many CO2 molecules are produced in glycolysis and how many in the Krebs cycle? - Answer-2 - Glycolysis, 4 - Krebs cycle How many ATP are produced during the Krebs cycle? - Answer-2 What happens to the remainder of the energy harvested through the Krebs cycle? - Answer-It is transferred to reduced coenzymes that will go through the ETC and be converted to ATP.