Chapter 19: Citric Acid Cycle 2

Question 1

citric acid cycle goal

Answer 1

acetyl-CoA + 3NAD+ +FAD +ADP +Pi +2H20 —> 2CO2 + 3NADH + FADH2 + ATP + 2H+ + CoASH

Question 2

Which two products of the citric acid cycle will go on to generate a lot of ATP?

Answer 2

3NADH
FADH2

Question 3

overview of citric acid cycle

Answer 3

-oxaloacetate and acetyl-CoA form citrate
-create a CO2 (oxidation)
-create an NADH (reduction)
-create another CO2 (oxidation)
-create another NADH (reduction)
-create an ATP
-create a FADH2
-create another NADH (reduction)

Question 4

What are the 2 other names for the citric acid cycle?

Answer 4

-tricarboxylic acid cycle (TCA cycle)
-Krebs cycle

Question 5

Anapleurotic reactions

Answer 5

reactions that put things into citric acid cycle as it goes along to replace what is being produced

ex: conversion of pyruvate to oxaloacetate
(takes something from out of the cycle and makes something that’s in the cycle)

ex: aspartate to make

Question 6

watewheel analogy

Answer 6

-stuff is constantly coming in and out throughout the cycle
-if there is a kink in this system, the cycle stops
-wheel moving is what generates the ATP we need

Question 7

how many reactions take place in the citric acid cycle?

Answer 7

8

Question 8

Citrate synthase formulas

Answer 8

-acetyl-CoA + oxaloacetate —> citryl-CoA
-citryl-CoA + water —> coenzyme A + citrate
-hydrolysis

Question 9

deltaG0’ of citrate synthase

Answer 9

-31.5 kj/mol
very negative
reaction goes forward
probably not reversible
a regulating step

Question 10

Probelm of citrate

Answer 10

-has to do the two step process in order to fit into the active site
-must exclude water for a little

Question 11

What is Aconitase

Answer 11

-lyase
-enzyme that sees hydroxyl group and hydrogen on citrate
-removes as water molecule
-creates cis double bond where water was

-puts water back into double bond but flipped around

Question 12

Aconitase formula

Answer 12

citrate —> cis-aconitate —> isocitrate