Cellular Respiration PDF

Question Answer What are the three major phases of aerobic cellular respiration? Glycolysis, Citric Acid Cycle, and Oxidative Phosphorylation. What is the primary function of glycolysis? To convert glucose int...

Question Answer What are the three major phases of aerobic cellular respiration? Glycolysis, Citric Acid Cycle, and Oxidative Phosphorylation. What is the primary function of glycolysis? To convert glucose into two 3-carbon pyruvate molecules. Where does glycolysis occur? In the cytosol. What is the first stage of the preparatory phase of glycolysis? Phosphorylation of glucose to produce glucose-6-phosphate. Which enzyme is responsible for the phosphorylation of Hexokinase. glucose? What is the role of phosphoglucose isomerase in glycolysis? To convert glucose-6-phosphate into fructose-6-phosphate. What happens during the second phosphorylation stage of Fructose-6-phosphate is phosphorylated to form glycolysis? fructose-1,6-bisphosphate. What does aldolase do in the glycolysis pathway? Converts fructose-6-phosphate into glyceraldehyde-3-phosphate (G3P) and dihydroxyacetone phosphate (DHAP). How is DHAP converted in glycolysis? It is converted into G3P by triose phosphate isomerase. What occurs during the oxidation stage of glycolysis? G3P-dehydrogenase removes hydrogens from G3P, converting NAD+ into NADH and producing 1,3-bisphosphoglycerate. What enzyme removes a phosphorus from Phosphoglycerate kinase. 1,3-biphosphoglycerates in Stage 7? What is produced when phosphoglycerate kinase removes a Two molecules of ATP and two molecules of phosphoglycerate. phosphorus from 1,3-biphosphoglycerates? What happens in Stage 8 of glycolysis? The phosphorus is moved into the middle of the molecule by phosphoglycerate mutase. What is the role of enolase in Stage 9? Enolase changes the orientation of the molecule and removes a water group, creating phosphoenolpyruvate. What occurs in Stage 10 of glycolysis? Pyruvate kinase eliminates the last phosphorus molecules, creating ATP and producing two molecules of pyruvate. What are the byproducts of glycolysis? 2 ATP, 2 NADH, and 2 Pyruvate. What happens to pyruvate if O2 is not available? Fermentation occurs in the cytoplasm. What happens to pyruvate if O2 is available? Pyruvate enters the mitochondria and is oxidized to acetyl CoA, which enters the citric acid cycle. What is the first step in the oxidation of pyruvate to acetyl CoA? Pyruvate dehydrogenase pulls a CO2 molecule off the pyruvate. What is reduced to NADH during the oxidation of pyruvate? NAD+. What is produced when an acetyl group is transferred to Acetyl Coenzyme A. Coenzyme A? What is the first product of the Citric Acid Cycle? Citric acid (citrate). What does the Citric Acid Cycle begin with? The formation of citric acid from acetyl-CoA and oxaloacetate. What are the overall products of the Krebs cycle? CO2, ATP, NADH, and FADH2. What is the role of aconitase in the Krebs cycle? It catalyzes the conversion of citrate to isocitrate. What happens to isocitrate in Stage 3 of the Krebs cycle? It undergoes dehydrogenation and decarboxylation to form α-ketoglutarate, releasing CO2. What enzyme catalyzes the conversion of α-ketoglutarate to α-ketoglutarate dehydrogenase enzyme complex. succinyl CoA? What is produced during the conversion of succinyl CoA to GTP, which transfers its phosphate to ADP to form ATP. succinate? What is the result of the oxidation of succinate in the Krebs Fumarate is formed, and FAD is converted to FADH2. cycle? What enzyme catalyzes the conversion of fumarate to malate? Fumarase. Question Answer What is formed when malate is dehydrogenated in Stage 8 of the Oxaloacetate. Krebs Cycle? What molecule combines with oxaloacetate to start a new cycle Acetyl CoA. in the Krebs Cycle? What is the role of malate dehydrogenase in the Krebs Cycle? It catalyzes the dehydrogenation of malate to form oxaloacetate. What are the byproducts of the Krebs Cycle? 2 ATP, 4 CO2, 6 NADH, 2 FADH2. What is the final electron acceptor in the electron transport Molecular oxygen. chain? What is created by the series of redox reactions in the electron An electrochemical gradient. transport chain? What is the function of ATP-synthase in chemiosmosis? To produce a large amount of ATP using the proton gradient. What does Complex 1 of the electron transport chain receive? Two electrons from NADH. What is the role of ubiquinone (Q) in the electron transport It connects Complex 1 and Complex 2 and delivers electrons to the chain. chain? What is the composition of Complex 3 in the electron transport Fe-S protein, Cytochrome b, and Cytochrome c. chain? What are the components of the electron transport chain Cytochrome c, a, and a3. mentioned? How many heme groups are present in cytochromes c and a3? Two heme groups. What does reduced oxygen combine with to form water? Hydrogen ions. How many ATPs does the electron transport chain yield as a About 32 ATPs. byproduct? What is the input for glycolysis? 1 glucose. What are the outputs of glycolysis? 2 NADH, 2 ATP, 2 pyruvate. What is the input for the Krebs cycle? 2 acetyl-CoA (from pyruvate). What are the outputs of the Krebs cycle? 4 CO2, 2 ATP, 6 NADH, 2 FADH2. What is the input for the electron transport chain? 10 NADH and 2 FADH. What is the total ATP output from cellular respiration? 36-38 ATP.