Cellular Respiration Questions and Answers Graded A+

Cellular Respiration Questions and Answers Graded A+ What is produced when glucose is broken down in the absence of oxygen? When oxygen is absent, glucose is broken down into lactic acid or ethanol and carbon dioxide, depending on the organism. What is the benefit of aerobic respiration over fermentation? Aerobic respiration produces significantly more ATP than fermentation, making it more efficient. Why is the citric acid cycle also called the Krebs cycle? It is called the Krebs cycle after Hans Krebs, the scientist who discovered it. What compound combines with acetyl-CoA to begin the Krebs cycle? Oxaloacetate combines with acetyl-CoA to begin the Krebs cycle. What happens to ADP during cellular respiration? ADP is phosphorylated into ATP during cellular respiration. 2 What is the role of carbon dioxide in cellular respiration? Carbon dioxide is a waste product released during the Krebs cycle and pyruvate oxidation. What causes the pH inside mitochondria to be lower than the intermembrane space? The high concentration of protons in the intermembrane space causes the pH to be lower inside the mitochondrial matrix. What molecule must be regenerated in glycolysis to allow it to continue? NAD+ must be regenerated to allow glycolysis to continue. What happens if a cell runs out of oxygen during respiration? The cell switches to anaerobic respiration or fermentation to produce ATP. What process in cellular respiration produces the most ATP? The electron transport chain produces the most ATP during cellular respiration. 3 Cellular Respiration The process that releases energy (ATP) by breaking down glucose. (converts food molecules (glucose) into a form usable (ATP) by the organism) Aerobic respiration Converting glucose into ATP in the presence of oxygen. Glycolysis, Kreb's cycle, ETC, total of 36-38 ATP, Location: mitochondria What gas is essential for aerobic cellular respiration to occur? Oxygen is essential for aerobic cellular respiration because it acts as the final electron acceptor in the electron transport chain. What molecule is the starting point for cellular respiration? Glucose is the starting molecule for cellular respiration and is broken down to release energy. Where in the cell does the Krebs cycle take place? The Krebs cycle takes place in the mitochondrial matrix. What are the three main stages of cellular respiration? The three main stages are glycolysis, the Krebs cycle, and the electron transport chain. 4 Why is glycolysis considered an anaerobic process? Glycolysis is anaerobic because it does not require