All of the following enzymes catalyze a committed step EXCEPT: HMG-CoA reductase Fatty acyl-CoA synthetase Acetyl-CoA carboxylase I Pyruvate dehydrogenase complex All of the above enzymes catalyze a committed step   The brain can directly use all of the following chemicals as energy source EXCEPT: Acetoacetate b-hydroxybutyrate Glucose Fatty acids All of the above can directly be used by the brain as energy source

Which of the following glycolytic enzymes catalyzes the conversion of fructose-1,6-bisphosphate into the two product molecules dihydroxyacetone phosphate, and glyceraldehyde-3-phosphate? phosphoglycerate kinase pyruvate kinase malate dehydrogenase aldolase phosphofructokinase

Which of the following statements is true for the shown reactions?   Deficiency of oxaloacetate stimulates the formation of X and y Insulin signaling stimulates the formation of X and Y Both A and B Neither A nor B

Each of the following enzymes are similar in that they are all regulation points for the pathway/cycle they operate in ... except for one enzyme. Which of the following is not a regulated enzyme? Pyruvate carboxylase Transketolase Glycogen phosphorylase Citrate Synthase Phosphofructokinase Acetyl CoA carboxylase 888888

Which of the following most accurately describes the impact acetyl-CoA has in the cytosol of the liver cell? Acetyl CoA serves as an allosteric inhibitor of PFK Acetyl CoA serves as an allosteric inhibitor of pyruvate kinase Acetyl CoA serves as an allosteric activator of PFK Acetyl CoA serves as an allosteric activator of pyruvate kinase Acetyl CoA serves as an allosteric activator of fructose-2,6-bisphosphatase Acetyl CoA serves as an allosteric activator of PFK-2

[References) Which of the following statements explains why acetyl-CoA Iis considered the central molecule of metabolism? (Select all that apply.) O The addition of acetyl-CoA to compounds stabilises them. Acetyl-CoA contains a thioester bond that makes it one of the high energy compounds in metabolic pathways. O Acetyl-CoA is an inhibitor that plays a central role in regulating metabolic pathways. O Acetyl-CoA feeds directly into the citric acid cycle. U None of the above.

In the liver, what is the fate of pyruvate under conditions of the Cori Cycle? Acetyl CoA to fuel TCA Conversion to oxaloacetate primarily for glucose biosynthesis Conversion to lactate Conversion to oxaloacetate primarily for amino acid biosynthesis

When acetyl-CoA containing radioactively labeled carbon atoms is fed to cells, the CO, produced is not initially radioactive. However, molecules of citrate and oxaloacetate are radioactive. Only after some time has passed will radioactive CO2 be released. What is the best explanation for this observation?

Which of the following catalyzes a step that does NOT produce CO2? Group of answer choices alpha-ketoglutarate dehydrogenase complex malate dehydrogenase pyruvate dehydrogenase complex isocitrate dehydrogenase   Citrate synthase is regulated by... Group of answer choices Concentrations of substrate and products Fructose-2,6-Bisphosphate Covalent modification Allosteric regulation by the levels of NADDH

Once formed, what are the three possible fates of pyruvate and under what conditions do they occur? Match the appropriate pairs.   Clear All pyruvate forms lactate pyruvate forms ethanol pyruvate forms acetyl-CoA   under anaerobic conditions in animals under aerobic conditions under anaerobic conditions in yeast and other microorganisms