1. Decarboxylation of pyruvate to acetyl-CoA is catalyzed by a multi-component enzyme through a multistep process. Two of the reaction steps do not involve the three carbons of pyruvate, yet are essential to the process. Explain why the process involves reaction steps that does not use the substrate, pyruvate.
2. What is the driving force for electron transport through the electron-transport chain?
3. Explain why less ATP is made from the reoxidation of FADH2 as compared to NADH.
4.Maximum ATP yield from cellular respiration is given as a theoretical number. However, this number actually is lower. Give 3 reasons why ATP yield in cellular respiration may be lower than the theoretical yield.
5.Which enzymes determine the rate of the citric acid cycle, and what are the allosteric factors that influence the flux through these enzymes?
Following information applies to the next 3 questions (questions 6-8):
Citrate is an intermediate in the citric acid cycle, which takes place in mitochondrial matrix in eukaryotic cells. However, citrate also has regulatory influence on glycolysis, which occurs in the cytosol.
6. How is citrate transferred to cytosol?
7.When is citrate transferred to cytosol?
8.How does citrate exert its regulatory action on glycolytic pathway?
9.Vertebrates cannot synthesize glucose from acetate, or the fatty acids that give rise to acetyl-CoA. However, plants can do so. Explain why plants have evolved with the capability to synthesize glucose from acetate?
10.How does glyoxylate cycle faciliate production of glucose from fatty acids?
11.How are the intermediates shared between glyoxylate and citric acid cycles partitioned in different pathways?