Concept explainers
To determine: The problems that would arise if acetyl-CoA were not converted to
Introduction:
Fatty-acid oxidation involves the breakdown of fatty acid molecules in order to generate acetyl-CoA. Then the acetyl-CoA enters into the citric acid cycle. Ketone bodies like acetone, D-β-hydroxybutyrate, and acetoacetate are formed from the excess amount of acetyl-CoA.
To determine: The way in which diversion of acetyl-CoA ketone bodies will solve the problem of depletion of coenzyme A pool.
Introduction:
Fatty-acid oxidation involves the breakdown of fatty acid molecules in order to generate acetyl-CoA. Then the acetyl-CoA enters into the citric acid cycle. Ketone bodies like acetone, D-β-hydroxybutyrate, and acetoacetate are formed from the excess amount of acetyl-CoA.

Want to see the full answer?
Check out a sample textbook solution
Chapter 17 Solutions
Lehninger Principles of Biochemistry (Instructor's)
- please answer all questions 1 identify the amino acids below by name and three letter abbrevarrow_forwardPyruvate is accepted into the TCA cycle by a “feeder” reaction using the pyruvatedehydrogenase complex, resulting in acetyl-CoA and CO2. Provide a full mechanismfor this reaction utilizing the TPP cofactor. Include the roles of all cofactors.arrow_forwardB- Vitamins are converted readily into important metabolic cofactors. Deficiency inany one of them has serious side effects. a. The disease beriberi results from a vitamin B 1 (Thiamine) deficiency and ischaracterized by cardiac and neurological symptoms. One key diagnostic forthis disease is an increased level of pyruvate and α-ketoglutarate in thebloodstream. How does this vitamin deficiency lead to increased serumlevels of these factors? b. What would you expect the effect on the TCA intermediates for a patientsuffering from vitamin B 5 deficiency? c. What would you expect the effect on the TCA intermediates for a patientsuffering from vitamin B 2 /B 3 deficiency?arrow_forward
- Draw the Krebs Cycle and show the entry points for the amino acids Alanine,Glutamic Acid, Asparagine, and Valine into the Krebs Cycle - (Draw the Mechanism). How many rounds of Krebs will be required to waste all Carbons of Glutamic Acidas CO2?arrow_forwardSodium fluoroacetate (FCH 2CO2Na) is a very toxic molecule that is used as rodentpoison. It is converted enzymatically to fluoroacetyl-CoA and is utilized by citratesynthase to generate (2R,3S)-fluorocitrate. The release of this product is a potentinhibitor of the next enzyme in the TCA cycle. Show the mechanism for theproduction of fluorocitrate and explain how this molecule acts as a competitiveinhibitor. Predict the effect on the concentrations of TCA intermediates.arrow_forwardIndicate for the reactions below which type of enzyme and cofactor(s) (if any) wouldbe required to catalyze each reaction shown. 1) Fru-6-P + Ery-4-P <--> GAP + Sed-7-P2) Fru-6-P + Pi <--> Fru-1,6-BP + H2O3) GTP + ADP <--> GDP + ATP4) Sed-7-P + GAP <--> Rib-5-P + Xyl-5-P5) Oxaloacetate + GTP ---> PEP + GDP + CO 26) DHAP + Ery-4-P <--> Sed-1,7-BP + H 2O7) Pyruvate + ATP + HCO3- ---> Oxaloacetate + ADP + Piarrow_forward
- TPP is also utilized in transketolase reactions in the PPP. Give a mechanism for theTPP-dependent reaction between Xylulose-5-phosphate and Ribose-5-Phosphate toyield Glyceraldehyde-3-phosphate and Sedoheptulose-7-Phosphate.arrow_forwardWhat is the difference between a ‘synthetase’ and a ‘synthase’?arrow_forwardIn three separate experiments, pyruvate labeled with 13C at C-1, C-2, or C-3 is introduced to cells undergoing active metabolism. Trace the fate of each carbon through the TCA cycle and show when each of these carbons produces 13CO2.a. Glucose is similarly labeled at C-2 with 13C. During which reaction will this labeled carbon be released as 13CO2?arrow_forward
- BiochemistryBiochemistryISBN:9781319114671Author:Lubert Stryer, Jeremy M. Berg, John L. Tymoczko, Gregory J. Gatto Jr.Publisher:W. H. FreemanLehninger Principles of BiochemistryBiochemistryISBN:9781464126116Author:David L. Nelson, Michael M. CoxPublisher:W. H. FreemanFundamentals of Biochemistry: Life at the Molecul...BiochemistryISBN:9781118918401Author:Donald Voet, Judith G. Voet, Charlotte W. PrattPublisher:WILEY
- BiochemistryBiochemistryISBN:9781305961135Author:Mary K. Campbell, Shawn O. Farrell, Owen M. McDougalPublisher:Cengage LearningBiochemistryBiochemistryISBN:9781305577206Author:Reginald H. Garrett, Charles M. GrishamPublisher:Cengage LearningFundamentals of General, Organic, and Biological ...BiochemistryISBN:9780134015187Author:John E. McMurry, David S. Ballantine, Carl A. Hoeger, Virginia E. PetersonPublisher:PEARSON





