BIO 132 METABOLISM PART 2 EXAM 2025 VERIFIED QUESTIONS AND GUARANTEED ANSWERS ALREADY GRADED A+(CERTIFIED).

BIO 132 METABOLISM PART 2 EXAM 2025 VERIFIED QUESTIONS AND GUARANTEED ANSWERS ALREADY GRADED A+(CERTIFIED). What are the three main metabolic pathways involved in cellular respiration? - Answer- Glycolysis, Krebs Cycle (Citric Acid Cycle), and Electron Transport System. Where does glycolysis occur? - Answer- In the cytoplasm of all cells. What is the end product of glycolysis? - Answer- 2 Pyruvic Acid molecules. What is the net ATP yield from glycolysis? - Answer- 2 ATP. What is the function of phosphofructokinase in glycolysis? - Answer- It regulates the rate of glycolysis and is inhibited by high levels of ATP. What are the two fates of pyruvate depending on oxygen availability? - Answer- With O2: aerobic respiration; without O2: fermentation. What is the role of coenzyme A in cellular respiration? - Answer- It carries 2-carbon units to the Krebs Cycle and forms Acetyl CoA. What is the primary purpose of the Krebs Cycle? - Answer- To harvest energy through a series of enzymatic reactions. What are the main products generated per turn of the Krebs Cycle? - Answer- 3 NADH, 1 FADH2, and 1 ATP. What is substrate-level phosphorylation? - Answer- The direct formation of ATP from ADP by transferring a phosphate group from a substrate. What is the electron transport chain (ETC) primarily responsible for? - Answer- Synthesizing ATP through oxidative phosphorylation. What is the significance of the mitochondrial inner membrane? - Answer- It contains the electron transport chain and is the site of ATP synthesis. What happens during the transition reaction before entering the Krebs Cycle? - Answer- Pyruvate is converted to Acetyl CoA, releasing CO2 and generating NADH. What is the end product of the Krebs Cycle? - Answer- Oxaloacetic acid (OAA), which allows the cycle to repeat. What is the role of NADH and FADH2 in cellular respiration? - Answer- They carry electrons to the electron transport chain for ATP production. What is the main waste product of the Krebs Cycle? - Answer- Carbon dioxide (CO2). How does the concentration of ADP affect the Krebs Cycle? - Answer- Increased ADP levels stimulate the cycle, while high ATP levels inhibit it. What is the 'endosymbiont theory' related to mitochondria? - Answer- It suggests that mitochondria are descendants of ancient prokaryotic cells. What is the importance of the cristae in mitochondria? - Answer- They increase the surface area for ATP synthesis during oxidative phosphorylation. What is the role of the intermembrane space in mitochondria? - Answer- It accumulates H+ ions, creating a gradient used to produce ATP. What are the two main types of phosphorylation in cellular respiration? - Answer- Substrate-level phosphorylation and oxidative phosphorylation. What is the function of pyruvate dehydrogenase (PDH)? - Answer- It catalyzes the conversion of pyruvate to Acetyl CoA. What is the significance of the Krebs Cycle intermediates? - Answer- They are used to synthesize nonessential amino acids, nucleic acids, and other important molecules. What is the main energy currency produced in cellular respiration? - Answer- ATP. What is the total ATP yield from one glucose molecule after complete cellular respiration? - Answer- Approximately 30-32 ATP. What happens to the energy harvested from glucose during cellular respiration? - Answer- It is stored in the form of ATP for cellular activities. What molecules power the electron transport chain (ETC)? - Answer- NADH and FADH2 What happens to NADH in the ETC? - Answer- NADH is oxidized to NAD+, which returns to the Krebs cycle to pick up more electrons and hydrogen. What is the role of cytochrome oxidase in the ETC? - Answer- Cytochrome oxidase is the last protein in the ETC that accepts low energy electrons and combines them with oxygen and hydrogen to form metabolic water. What is the final electron acceptor in the ETC? - Answer- Oxygen (O2) What occurs if there is a lack of oxygen in the ETC? - Answer- The electron transport chain slows or stops, leading to a metabolic problem. What is the function of ATP synthase in oxidative phosphorylation? - Answer- ATP synthase uses the proton motive force from the H+ gradient to produce ATP from ADP and inorganic phosphate (Pi). What is chemiosmosis? - Answer- The process where H+ ions flow from high to low concentration through ATP synthase, releasing kinetic energy to produce ATP. What is unique about brown adipose tissue regarding the electron transport chain? - Answer- Brown adipose tissue contains mitochondria with an electron transport system but no ATP synthase, allowing H+ to flow back without producing ATP, resulting in energy loss as heat. How much ATP is produced per NADH in oxidative phosphorylation? - Answer- 2.5 ATP per NADH How much ATP is produced per FADH2 in oxidative phosphorylation? - Answer- 1.5 ATP per FADH2 What is the net gain of ATP from glucose metabolism in most tissues? - Answer- 30 ATP, except in heart, kidney, and liver where it is 32 ATP. What is lactic acid fermentation? - Answer- A process that occurs in anaerobic conditions to regenerate NAD+ from NADH, allowing glycolysis to continue. What metabolic problem arises when NAD+ is not regenerated? - Answer- The electron transport chain slows or stops. What happens to lactic acid in the body? - Answer- Lactic acid is transported to the liver via blood and converted back to glucose through gluconeogenesis.