Glycolysis requires only phosphorylation and does not involve dephosphorylation. Which is NOT characteristic of metabolism during the absorptive state? When they react with CoA, the combined molecule becomes acetyl-CoA. Which of the following is a result of the Krebs cycle? d. all of these choices are possible fates of an amino acid. The oxidation also produces one NADH molecule and releases one carbon dioxide (CO 2) molecule. Which of the following plays a key role in metabolism? The oxidative conversion of pyruvate into acetyl-CoA is referred to as the pyruvate dehydrogenase reaction. The main function of this cycle is the oxidation of acetyl-CoA to CO 2 and H 2 O. A molecule of CO 2 is evolved here and the acetyl coenzyme A, thus formed enters the cycle proper and in presence of water, and condensing enzymes, react with oxalacetic acid obtained from the cycle, to produce 6-carbon citric acid and making the cycle ‘go’ normally in a clockwise manner. Acetyl Coenzyme A. is formed through oxidation of pyruvic acid. Shivering on a cold day to maintain body temperature is an example of energy homeostasis. The product has less potential energy than the reactant. Which of the following is NOT a postabsorptive state reaction? What does pyruvic-acid mean? 2. where RSH is coenzyme A; it contains S and pantothenic acid. Pyruvic acid undergoes several changes to become acetyl Coenzyme A (acetyl CoA). The acetyl CoA molecule enters the citric acid or Krebs cycle, continuing the process of cellular respiration. Enter mitochondria and be oxidized to acetyl-CoA via pyruvate dehydrogenase. Oleoyl-CoA then undergoes three passes through the fatty acid oxidation cycle to yield three molecules of acetyl-CoA and the coenzyme A ester of a Δ 3, 12-carbon unsaturated fatty acid, cis-Δ 3 dodecenoyl-CoA (Fig. Acetyl coenzyme A a) is formed through oxidation of pyruvic acid b) formation requires pyruvate dehydrogenase c) occurs under aerobic conditions d) links glycolysis to the Krebs cycle e) all of these choices are correct The latter enters the Krebs cycle. It is also used in the body to synthesize the amino acid alanine. One of the starting materials for the citric acid is ACETYL CO-ENZYME A and this molecule is formed partly through the removal of carbon from one molecule of PYRUVIC ACID. When the terminal phosphate is cut off of ATP what is formed? The increased ketogenesis seen during starvation decreases glucose usage and gluconeogenesis, thus indirectly decreasing catabolism of muscle protein for energy needs. The conversion of pyruvate to acetyl CoA is a three-step process. Glucose is stored in the liver and muscle in the form of. The latter may further change into pyruvic acid or acetyl coenzyme A. Pyruvic acid is oxidized to acetyl coezyme A. Once pyruvate enters the matrix, it is converted into an acetyl group, which is then temporarily bonded to a sulfur atom on the end of a large molecule called coenzyme A, or CoA. The pyruvic acid is formed by oxidation through the glycolytic path. The acetyl CoA formed from pyruvic acid (i.e., from carbohydrate breakdown) can be used to synthesize fats and likewise so can acetyl CoA produced as a result of protein metabolism. Acetyl is produced by the breakdown of pyruvate, a derivative of carbohydrate. The citric acid cycle, also called the Krebs cycle or the tricarboxylic acid (TCA) cycle, occurs in the mitochondria. Which of the following transport dietary lipids? A carboxyl group is removed from pyruvate, releasing a molecule of carbon dioxide into the surrounding medium. 17. b) is endergonic, requiring more energy than is produced, If glucose is not immediately needed for ATP production _______ may occur, d) all of these choices are possible fates of an amino acid, For adequate absorption, all of the following require ingestion with other lipids EXCEPT, If adequate O2 is present in the mitochondria, pyruvic acid will be converted to _____; if conditions are anerobic, pyruvic acid will be converted to ________, The formation of glucose from proteins and fats is called, Fatty acids may be converted to acetyl CoA through a process called, c) play an important part in energy transfer, Glucose is stored in the liver and muscle in the form of. Cells commonly use multistep biochemical reactions to capture energy from lower-energy compounds to release to and enhance the energy of high-energy compounds. 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