Microbiology: An Evolving Science (Fourth Edition)
4th Edition
ISBN: 9780393615098
Author: John W. Foster, Joan L. Slonczewski
Publisher: W. W. Norton & Company
expand_more
expand_more
format_list_bulleted
Question
Chapter 13.6, Problem 2TQ
Summary Introduction
To review:
The comparison of reactions catalyzed by pyruvate dehydrogenase and pyruvate formate lyase and the conditions favoring them.
Introduction:
Pyruvate lies at a crossroad of essential energy metabolic pathways. It is the final product of glycolysis and marks the start of gluconeogenesis. It can be created by alanine transamination. It can be transformed into acetyl CoA (Coenzyme A) by the pyruvate dehydrogenase complex. Acetyl CoA can join the TCA (tricarboxylic acid) cycle or act as the starting point for the synthesis of steroids, fatty acids, and
Expert Solution & Answer
Want to see the full answer?
Check out a sample textbook solution
Students have asked these similar questions
Arsenate (HAsO42-) can replace inorganic phosphate (Pi) in the reaction catalyzed by glyceraldehyde 3-phosphate dehydrogenase, causing Glyceraldehyde 3-phosphate to be directly converted to 3-phosphoglycerate (NADH is still formed). If a cell is expose to Arsenate, which of the following metabolites of glycolysis will not be detectable in the cell?
2-phosphoglycerate
3-phosphoglycerate
Fructose 6-phosphate
Glucose 6-phosphate
1,3-bisphosphoglycerate
Arsenate (HASO42-) can replace inorganic phosphate (Pi) in the reaction catalyzed by glyceraldehyde 3-phosphate dehydrogenase,
causing Glyceraldehyde 3-phosphate to be directly converted to 3-phosphoglycerate (NADH is still formed). If a cell is expose to
Arsenate, which of the following metabolites of glycolysis will not be detectable in the cell?
2-phosphoglycerate
B 3-phosphoglycerate
Fructose 6-phosphate
Glucose 6-phosphate
E 1,3-bisphosphoglycerate
For each of the central pathway intermediates given below, calculate how many ATP equivalents can be generated by complete oxidation of the compound to CO2:
1. Acetyl-CoA
2. Pyruvate
3. GAP (glyceraldehyde-3-phosphate)
And please explain why.
Chapter 13 Solutions
Microbiology: An Evolving Science (Fourth Edition)
Knowledge Booster
Similar questions
- The “bridge reaction”, using pyruvate dehydrogenase, is highly exergonic and is essentially irreversible. Name the 3 outcomes (name any activated carriers produced, name the molecule that is produced from losing one carbon atom from pyruvate, and name any modification to the remaining two carbon compound of interest ) of the separate enzyme activities found within the large dehydrogenase complex.arrow_forwardIf α-ketoglutarate is removed from TCA cycle and used to make glutamate, how many of each of the cofactors (not intermediates) and high energy molecules in the TCA cycle are lost? How much ATP does this equate to (NADH = 2.5 ATP, FADH2 = 1.5 ATP)?arrow_forwardRefer to Figure, which indicates ∆G for each glycolytic reaction under intracellular conditions. Assume that glyceraldehyde-3-phosphate dehydrogenase was inhibited with iodoacetate, which reacts with its active site cysteine sulfhydryl group. Which glycolytic intermediate would you expect to accumulate most rapidly, and why?arrow_forward
- In 1937, two German biochemists published a paper proposing these reactions as part of glucose oxidation: citrate → isocitrate → α-ketoglutarate →succinate → fumarate → malate → oxaloacetate. Adding succinate, fumarate, or malate to thin slices of tissue increased oxygen consumption, supporting the hypothesis that these molecules are intermediates in the process. However, they were puzzled by the observation that these intermediates were still present in the reaction mixture at the end of the experiment. They had thought that intermediates would be consumed as they were converted to the next molecule in the pathway. What explains the observation that these intermediates were still present? a) The pathway is a cycle, constantly regenerating intermediates as glucose is broken down. b) Succinate, fumarate, and malate are not reactants but catalysts, and catalysts are not consumed in the process. c) Succinate, fumarate, and malate increase metabolism and therefore oxygen consumption,…arrow_forwardExplain why the use of the ATP analog below in the reaction catalyzed by pyruvate carboxylase might lead to a carboxylated ATP derivative rather than the normal product oxaloacetatearrow_forwardDescribe in detail the structure of the pyruvate dehydrogenase complex.arrow_forward
- The PDH complex is a logical point of regulation in metabolism, as it links two major catabolic processes. Answer the following regarding the complex: a) Explain the advantage of E1, E2 and E3 working as a complex as opposed to separately. b) Explain the purpose of each of the three enzymes and their associated cofactors. c) NADH can inhibit the PDH complex directly or indirectly. What is the purpose of inhibition by NADH? d) Explain the differences between direct and indirect inhibition by NADH. Be sure to indicate the components involved and the mechanism of inhibition (impact on target component).arrow_forwardBased on the action of thiamine pyrophosphate in catalysis of the pyruvate dehydrogenase reaction, suggest a suitable mechanism for the fourth step in the pyruvate decarboxylase reaction in yeast:arrow_forwardCertain microorganisms with an incomplete citric acid cycle decarboxylate α-ketoglutarate to produce succinate semialdehyde. A dehydrogenase then converts succinate semialdehyde to succinate. These reactions can be combined with other standard citric acid cycle reactions to create a pathway from citrate to oxaloacetate. Compare the ATP and reduced cofactor yield of the standard and alternate pathways.arrow_forward
- Consider the mechanism of the aldolase reaction given in figure 9.25. In chapter 12, we saw that the same enzyme was used to catalyze the reverse reaction, DHAP + glyceraldehyde-3-phosphatefructose-1,6-bisphosphate, in the first step of stage 3 in the Calvin Cycle. Using arrows and structures similar to what is shown in 9.25, propose a mechanism for this reverse reaction (which is an aldol condensationarrow_forwardWhy does it make sense that under conditions of low ATP levels in the cell the pyruvate carboxylase reaction is activated by acetyl-Coenzyme A, whereas the pyruvate dehydrogenase reaction is activated by Coenzyme A under these same conditions? When acetyl-Coenzyme A levels build-up, then pyruvate carboxylase generates oxaloacetate for the citrate synthase reaction, whereas when Coenzyme A builds up, then acetyl-Coenzyme A needs to be generated by pyruvate dehydrogenase to maintain flux through the citrate cycle. When Coenzyme A levels build-up, then pyruvate dehydrogenase generates oxaloacetate for the citrate synthase reaction, whereas when acetyl-Coenzyme A builds up, then Coenzyme A needs to be generated by pyruvate carboxylase to maintain flux through the citrate cycle. Oxaloacetate is needed for the citrate synthase reaction, but acetyl-Coenzyme A is needed for the pyruvate dehydrogenase reaction, so it is actually under conditions of low ATP levels that these enzymes are…arrow_forwardIndicate which of the pathways for pyruvate acetyle CoA, lactate, and/or ethanol occur under each of the following conditions.arrow_forward
arrow_back_ios
SEE MORE QUESTIONS
arrow_forward_ios
Recommended textbooks for you
Human Anatomy & Physiology (11th Edition)BiologyISBN:9780134580999Author:Elaine N. Marieb, Katja N. HoehnPublisher:PEARSON
Biology 2eBiologyISBN:9781947172517Author:Matthew Douglas, Jung Choi, Mary Ann ClarkPublisher:OpenStax
Anatomy & PhysiologyBiologyISBN:9781259398629Author:McKinley, Michael P., O'loughlin, Valerie Dean, Bidle, Theresa StouterPublisher:Mcgraw Hill Education,
Molecular Biology of the Cell (Sixth Edition)BiologyISBN:9780815344322Author:Bruce Alberts, Alexander D. Johnson, Julian Lewis, David Morgan, Martin Raff, Keith Roberts, Peter WalterPublisher:W. W. Norton & Company
Laboratory Manual For Human Anatomy & PhysiologyBiologyISBN:9781260159363Author:Martin, Terry R., Prentice-craver, CynthiaPublisher:McGraw-Hill Publishing Co.
Inquiry Into Life (16th Edition)BiologyISBN:9781260231700Author:Sylvia S. Mader, Michael WindelspechtPublisher:McGraw Hill Education
Human Anatomy & Physiology (11th Edition)
Biology
ISBN:9780134580999
Author:Elaine N. Marieb, Katja N. Hoehn
Publisher:PEARSON
Biology 2e
Biology
ISBN:9781947172517
Author:Matthew Douglas, Jung Choi, Mary Ann Clark
Publisher:OpenStax
Anatomy & Physiology
Biology
ISBN:9781259398629
Author:McKinley, Michael P., O'loughlin, Valerie Dean, Bidle, Theresa Stouter
Publisher:Mcgraw Hill Education,
Molecular Biology of the Cell (Sixth Edition)
Biology
ISBN:9780815344322
Author:Bruce Alberts, Alexander D. Johnson, Julian Lewis, David Morgan, Martin Raff, Keith Roberts, Peter Walter
Publisher:W. W. Norton & Company
Laboratory Manual For Human Anatomy & Physiology
Biology
ISBN:9781260159363
Author:Martin, Terry R., Prentice-craver, Cynthia
Publisher:McGraw-Hill Publishing Co.
Inquiry Into Life (16th Edition)
Biology
ISBN:9781260231700
Author:Sylvia S. Mader, Michael Windelspecht
Publisher:McGraw Hill Education