Fatty acids are activated for breakdown through the action of acyl-CoA synthestase. Which of the followingstatements regarding acyl-CoA synthetase is not true?● It catalyzes the addition of CoA to the fatty acidOne of the products of the reaction is ADP.O The free energy change for the reaction catalyzed by this reaction is close to 0 kJ/mol, but the subsequent hydrolysis ofpyrophosphate drives the reaction forward.O The reaction results in the formation of a thioester bond.

Fatty acids are oxidised in the mitochondria. The fatty acid cannot enter the mitochondria but fatty…

Answered: Fatty acids are activated for breakdown…

Biochemistry

6th Edition

ISBN:9781305577206

Author:Reginald H. Garrett, Charles M. Grisham

Publisher:Reginald H. Garrett, Charles M. Grisham

Chapter23: Fatty Acid Catabolism

Section: Chapter Questions

Problem 16P: Extending the Mechanism of Methylmalonyl-CoA Mutase to Similar Reactions Based on the mechanism for...

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Extending the Mechanism of Methylmalonyl-CoA Mutase to Similar Reactions Based on the mechanism for the methylmalonyl-CoA mutase (see problem 14), write reasonable mechanisms for the following reactions shown.
Using the ActiveModel for enoyl-CoA dehydratase, give an example of a case in which conserved residues in slightly different positions can change the catalytic rate of reaction.
Fatty acids are converted to their coenzyme A esters in a reversible reaction catalyzed by acyl-CoA synthetase: R-COO +ATP +COA R-C-COA +AMP + PPi a) The reaction involves two steps the first of which forms an enzyme-bound intermediate identified as the mixed anhydride of the fatty acid and AMP: R-C-O-P-O-nibose-adenine Write two chemical equations coresponding to the two steps of the reaction catalyzed by the synthetase. b) The acyl-CoA synthetase reaction as written above is readily reversible. How might the reaction be made to favor formation of fatty acyl-CoA? Write within the box. Anything outside the box will not be graded. From the
Decylic acid is a saturated fatty acid that occurs naturally in coconut oil and palm kernel oil. Calculate the net ATP yield when decylic acid undergoes complete B oxidation. The formula of decylic acid is shown below: (Given: The oxidation of one NADH yields 2.5 ATP; the oxidation of one FADH2 yields 1.5 ATP; and the oxidation of one acetyl CoA yields 10 ATP.) O 50 ATP O 52 ATP 66 ATP OH O 64 ATP
The formation of acetyl-CoA from acetate is an ATP-driven reaction: Acetate + ATP + CoA Acetyl CoA + AMP + PP₁ Calculate AG" for this reaction given that the AG' for the hydrolysis of acetyl CoA to acetate and CoA is −31.4 kJ mol-¹ (−7.5 kcal mol¯¹) and that the AG°' for hydrolysis of ATP to AMP and PP; is -45.6 kJ mol-¹ (−10.9 kcal mol−¹ ). AG° reaction = AGO! i The PP, formed in the preceding reaction is rapidly hydrolyzed in vivo because of the ubiquity of inorganic pyrophosphatase. The AG" for the hydrolysis of pyrophosphate (PP;) is −19.2 KJ mol-¹ (-4.665 kcal mol-¹). Calculate the AGº' for the overall reaction, including pyrophosphate hydrolysis. reaction with PP, hydrolysis = What effect does the presence of pyrophosphatase have on the formation of acetyl CoA? kJ mol-¹ It does not affect the overall reaction. It brings the overall reaction closer to equilibrium. It makes the overall reaction even more exergonic. It makes the overall reaction even more endergonic. kJ mol-¹ -1
Compare and contrast Pyruvate Dehydrogenase with a-ketoglutarate dehydrogenaseOutline the mechanisms of both enzymes. Discuss the functions of the coenzymes. List the similarities and the differences between the 2 enzymes. Both are very large membrane bound complexes. What are the advantages of this strategy?How detailed is the enzyme structure known below(It's Pyruvate Dehydrogenase )? What insight(s) does this structural detail give you about the enzyme mechanism.
The synthesis of the activated form of acetate (acetyl-CoA) is carried out in an ATP-dependent process: Acetate + CoA + ATP → acetyl-CoA + AMP + PPi (a) The ∆G’o for the hydrolysis of acetyl-CoA to acetate and CoA is - 32.2 kJ/mol and that for hydrolysis of ATP to AMP and PPi is - 30.5 kJ/mol. Calculate ∆G’o for the ATP-dependent synthesis of acetyl-CoA. (b) Almost all cells contain the enzyme inorganic pyrophosphatase, which catalyzes the hydrolysis of PPi to Pi. What effect does the presence of this enzyme have on the synthesis of acetyl-CoA? Explain.
Behenate (C22H44O2) can be obtained by chain elongation from palmitate. How many ATP equivalents are produced in the degradation of behenate to eleven acetyl-CoA?
Compare and contrast Pyruvate Dehydrogenase with a-ketoglutarate dehydrogenaseOutline the mechanisms of both enzymes. Discuss the functions of the coenzymes. List the similarities and the differences between the 2 enzymes. Both are very large membrane bound complexes. What are the advantages of this strategy?Do a bit or research on the structure one of these enzymes. (include one recent reference) – How detailed is the enzyme structure known? What insight(s) does this structural detail give you about the enzyme mechanism.
(i) Consider a preparation that contains all the enzymes and cofactors necessary for fatty acid biosynthesis from acetyl-CoA and malonyl-CoA. If [2-H] acetyl-CoA labeled with deuterium, the heavy isotope of hydrogen and excess of unlabeled malonyl-CoA are added as substrates, where will you find these labeled deuterium atoms in a molecule of palmitate synthesized? Explain. S-COA (ii) Describe the steps involved in the synthesis of palmitic acid starting from acetyl-CoA and malonyl-CoA.
(b) ☐ The exergonic reactions catalyzed by isocitrate dehydrogenase (ICDH) and α- ketoglutarate dehydroge-nase (aKGDH) are regu- lated by metabolites, in addition to the reaction catalyzed by citrate synthase. The diagram to the right illustrates the activity of ICDH (A,▲) and aKGDH (O,●) in the presence of 1.5 mM ADP (O,A) or 1.5 mM ATP (●,▲). In muscle tissue contraction of sarcomeres initiated by a nerve im- pulse results first in the release of Ca 2+ from the sarcoplasmic reticulum. As indicated by the chang- es in velocity of the two enzymes, what are the flux changes of the TCA cycle in muscle tissue upon release of Ca2+ under the influence of ADP viz. ATP and under the influence of NAD+ viz. NADH on cit- rate synthase? 100 75 Stimulation of activity (% of maximum) ŏ 25 1. -8 -7 -6 log {[Ca2+] (M)}
Anabolic reactions like fatty acid synthesis are inherently endergonic and require exergonic driving forces to proceed forward. Which of the following statements correctly describes the thermodynamics at play in the substrate activation step of fatty acid synthesis and the importance of this step in downstream elongation of the fatty acid chain? (A) Acetyl CoA carboxylase (ACC1) provides free energy that powers the carboxylation of acetyl CoA to form malonyl CoA.(B) The formation of malonyl CoA is powered by the exergonic carboxylation of acetyl CoA.(C) The formation of a b-ketoacyl ACP in the first step of fatty acid synthesis is driven forward because b-ketoacyl synthase hydrolyzes ATP. (D) The addition of two carbons to the growing fatty acid chain is powered by malonyl ACP decarboxylation.(E) Decarboxylation of malonyl ACP is exergonic and the free energy that is released is coupled to ATP synthesis.

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