BI110 Study Guide - Final Guide: Malate Dehydrogenase, Succinate Dehydrogenase, Succinyl-Coa

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erinclam627

14 Dec 2016

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Once glycolysis occurs in the cytosol; the 2 molecules of pyruvate produced is transported to the mitochondrial matrix. Catalyzed by a large complex called pyruvate dehydrogenase: first, pyruvate is decarboxylated (1 co2 molecule is released, the remaining two-carbon acetyl group is made into coenzyme a (coa, coa forms acetyl coenzyme a (acetyl-coa) This conversion of pyruvate to acetyl coa is exergonic. Pyruvate + coa + nad+ acetyl coa + nadh + h+ + co2. The citric acid cycle (krebs cycle) also occurs in the mitochondrial matrix acetyl coa is oxidized through a series of 8 enzyme catalyzed reactions. Each molecule of acetyl coa, the citric acid cycle produces: 2 co2, 1 atp, 3 nadh, 1 fadh2. 1 acetyl-coa + 3nad+ + 1fad + 1adp+ 1pi +2h2o. 2 co2 + 3 nadh + 1 fadh2 + 1 atp + 3 h+ + 1. Complex i then oxidizes nadh into nad+

Related Questions

After glycolysis and before the citric acid cycle (TCA), the pyruvate dehydrogenase complex breaks down the pyruvate to three separate components; a carboxyl group, a two-carbon fragment, and coenzyme A (CoA). What happens next to these products?

a. The carboxyl group is reduced and released as CO2, the two-carbon fragment is used to reduce NADH, and CoA is converted to acetyl CoA for the TCA.

b. The carboxyl group is oxidized and released as CO2, the two-carbon fragment is used to oxidize NAD+, and CoA is converted to acetyl CoA for glycolysis.

c. The carboxyl group is used to reduce NAD+, the two-carbon fragment is oxidized and released as CO2, and CoA is oxidized to acetyl CoA for oxidative phosphorylation the TCA.

d. The carboxyl group is oxidized and released as CO2, the two-carbon fragment is used to reduce NAD+, and CoA is converted to acetyl CoA for the TCA.

e. The carboxyl group is used to oxidize NAD+, the two-carbon fragment is reduced and released as CO2, and CoA enters the TCA.

Where does each of these processes take place within the cell? Possible answers: cytosol, mitochondrial matrix, lysosome, nucleus, inner mitochondrial membrane, outer mitochondrial membrane, mitochondrial intermembrane space

1. Glycolysis cytosol

2. citric acid cycle Mitochondrial Matrix

3. conversion of pyruvate to activated acetyl groups

4. oxidation of fatty acids to acetyl CoA

5. glycogen breakdown

6. release of fatty acids from triacylglycerols

7. oxidative phosphorylation

bronzeimpala88

1. Choose the TWO correct statements describing the citrate cycle.

	ATP is an indirect product of the citric acid cycle
	Acetyl CoA can increase the pool of citric acid cycle intermediates
	Fatty acids can increase the pool of citric acid cycle intermediates
	ADP inhibits Î±-ketoglutarate dehydrogenase
	The pool of mitochondrial oxaloacetate can be increased by pyruvate
	All enzymes of the citric acid cycle are found soluble and free in the mitochondrial matrix

2.Which molecule in the net reaction of the citrate cycle contributes to the inhibition of pyruvate dehydrogenase?

	NADH
	H⁺
	H₂O
	FAD

3. How would a high NADH to NAD⁺ ratio be expected to affect the pyruvate dehydrogenase reaction?

	The E1 subunit is phosphorylated by pyruvate dehydrogenase kinase, and the catalytic activity of pyruvate dehydrogenase decreases.
	The last step of the pyruvate dehydrogenase reaction is blocked, resulting in a decrease in activity.
	The pyruvate dehydrogenase phosphatase-1 enzyme would increase, resulting in pyruvate dehydrogenase activation at an accelerated rate.
	The pyruvate dehydrogenase kinase enzyme activity would increase, resulting in an increase in pyruvate dehydrogenase activity.

BI110 Study Guide - Final Guide: Malate Dehydrogenase, Succinate Dehydrogenase, Succinyl-Coa

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