Chapter 17

Mitochondria

where does the citric acid cylce take place in the cell

flavoproteins

these enzymes are tightly associated with FAD or FMN

cis-aconitate

This is the intermediate between citrate and isocitrate

inner membrane

this is the location of succinate dehydrogenase

oxaloacetate

this intermediate is both at teh beginning and at the end of the citric acid cycle

carbon dioxide

this is one of the products of the citric acid cycle

glyoxylate cycle

a pathway that allows glucose synthesis from acetyl-CoA

arsenite

this substance is toxic because it reacts with the neighboring sulfhydryl groups of dihydrolipoyl groups and blocks its reoxidation to lipoamide

phosphorylation

this type of enzyme regulation process inhibits the pyruvate dehydrogenase complex

anaplerotic

this is the name applied to metabolic reactions that replensih citirc acid cycle intermediates taht are depleted because they were used for biosynthesis

acetyl CoA

carbons from carbohydrate enter the citric acid cycle in the form of ____

GTP

in the citric acid cycle, the _____ is produced by a substrate level phosphorylation

thiamine pyrophosphate

E1 of the pyruvate dehydrogenase complex requries the coenzyme ____ for proper activity

lysine

E2 of the pyruvate dehydrogenase complex contains a lipoyl group that is convalently attached to a _____ residue of the enzyme

aconitase

is a citric acid cycle enzyme that is also an example of an iron sulfur protein

glyoxylate

the ____ cycle is a process by which plants and some bacteria can convert two carbon acetyl units into four carbon units for glucose synthesis, energy production, and biosynthesis

acetyl CoA

most organisms cannot convert _____ into glucose because of the two decarboxylations in the citric acid cycle

high

in general, the citric cycle is inhibited under ______ energy condition

isocitrate

the first citric acid intermediate to be oxidized

thiamine

beri beri is caused by a deficency of _____

The citric acid cycle is known as the what?

krebs cycle and tricarboxylic acid cycle

What molecule initiates the citric acid cycle by reacting with oxaloacetate?

Acetyl CoA

What are the steps involved in the conversion of pyruvate to acetyl CoA?

Decarboxylation, oxidation, transfer to CoA

Which of the following vitamins are precursors to coenzymes that are necessary for the formation of acetyl CoA from pyruvate?

thiamine, riboflavin, niacin, lipoic acid, and pantothenic acid

which of the following functions as a flexible swinging arm when it transfers the reaction intermediate from on e active site to the next

Lipoamide

Formation of citrate from acetyl CoA and oxaloacetate is a _____ reaction

condensation

what is the chemcial change involved in the conversion of citrate into isocitrate

dehydration followed by hydration

in which reaction is GTP directly formed in the citric acid cycle?

Conversion of succinyl coa to succinate

The enzymes in the glyoxylate cycle are the same as the citric acid cycle except for?

malate synthase and glyoxylate synthase

What conditions will activate pyruvate dehydrogenase?

elevated concentrations of NADH and ATP

aprroximately how many atp or gto equivalents are produced during one turn of the citric acid cycle

10

in addition to pyruvate dehydrogenase, what other enxymes are key regulatory sites in the citric acid cycle

malate dehydrogenase and a ketoglutarate dehydrogenase

the glycoxylate cycle enables plants to survive using only

acetate