Citric Acid Cycle

Question 1

<p>Where does the citric acid cycle occur?</p>

Answer 1

<p>Matrix of the mitochondria</p>

Question 2

<p>Why is the citric acid cycle very efficient?</p>

Answer 2

<p>Does not need many intermediate compounds</p>

Question 3

<p>What does the citric acid cycle act as a gateway for?</p>

Answer 3

<p>Any compound that can be converted into acetyl coenzume A or a component of the cycle to enter aerobic respiration</p>

Question 4

<p>How does the citric acid cycle produce ATP?</p>

Answer 4

<p>Not directly, but through the use of electron carriers that then go to the electron transport chain and produce ATP</p>

Question 5

<p>What does the citric acid cycle do?</p>

Answer 5

<p>Removes electrons from intermediates and passes them onto NADH and FADH₂</p>

Question 6

<p>Is O₂used in the citric acid cycle?</p>

Answer 6

<p>No</p>

Question 7

<p>What does the use of O₂allow for glucose?</p>

Answer 7

<p>It to be completely broken down into CO₂and all of its energy to be stored</p>

Question 8

<p>What substances can be broken down into acetyl coenzyme A and enter the citric acid cycle?</p>

Answer 8

<p>Glucose</p>

<p>Fatty acids</p>

<p>Amino acids</p>

Question 9

What does the overall metabolism process look like (glycolysis, citric acid cycle and the electron transport chain)?

Answer 9

Question 10

<p>Why are substances like glucose broken down in lots of little steps and not all at once?</p>

Answer 10

<p>It allows packets of energy to be stored, breaking down the compound at once would release to much enery to be capture so most of it would be lost as heat</p>

Question 11

<p>What does acetyl coenzyme A allow?</p>

Answer 11

<p>Many intermediates to enter the citric acid cycle</p>

Question 12

<p>What enzyme coverts pyruvate into acetly coenzyme A?</p>

Answer 12

<p>Pyruvate dehydrogenase complex</p>

Question 13

<p>How many sub units is pyruvate dehydrogenase complex composed of?</p>

Answer 13

<p>Ten copies of each sub unit(E₁+ E₂+ E₃)</p>

Question 14

<p>What does each subunit of pyruvate dehdrogenase complex do?</p>

Answer 14

<p>Catalyses a different part of the reaction</p>

Question 15

<p>What happens to the concentration of the intermediates within the citric acid cycle?</p>

Answer 15

<p>They remain constant as each turn 2 carbons enter (acetyl coenzyme A) and 2 carbons leave (as 2 CO₂)</p>

Question 16

What does the citric acid cycle look like in terms of the amount of carbon each complex has and the use of electron carriers?

Answer 16

Question 17

What are the intermediates of the citric acid cycle?

Answer 17

1. citrate
2. iso-citrate
3. alpha-ketoglutarate
4. succinate
5. fumarate
6. malate
7. oxaloacetate

Question 18

<p>What do intermediate products of the citric acid cycle and ATP do to pyruvate dehydrogenase complex?</p>

Answer 18

<p>Regulate it</p>

Question 19

<p>What substance inhibit pyruvate dehydrogenase complex?</p>

Answer 19

<p>Acetyl coenzyme A</p>

<p>NADH</p>

<p>ATP</p>

Question 20

<p>What substances activate pyruvate dehydrogenase complex?</p>

Answer 20

<p>Pyruvate</p>

<p>ADP</p>

Question 21

<p>What does the regulation of pyruvate dehydrogenase complex mean?</p>

Answer 21

<p>Energy is not generated when it is not needed</p>

Question 22

<p>What are the points of control in the citric acid cycle other than the inhibition of pyruvate dehdrogenase complex?</p>

Answer 22

<p>Regulating the irreversible steps</p>

Question 23

<p>What enzymes control the irreversible steps of the citric acid cycle that can be regulated?</p>

Answer 23

<p>Isocitrate dehydrogenase and a-ketoglutamate dehydrogenase</p>

Question 24

<p>What does ATP and NADH do to isocitrate dehyrogenase?</p>

Answer 24

<p>Inhibit it</p>

Question 25

<p>What does ADP do to isocitrate dehydrogenase?</p>

Answer 25

<p>Activate it</p>

Question 26

<p>What does ATP, NADH and sucoinyl do to a-ketoglutamate dehydrogenase?</p>

Answer 26

<p>Inhibit it</p>

Question 27

<p>What does controlling the irreversible steps of the citric acid cycle allow for?</p>

Answer 27

<p>The build up of intermediates (citrate and a-ketoglutamate) which can be used elsewhere</p>

Question 28

<p>What kind of pathway is the citric acid cycle?</p>

Answer 28

<p>Amphibolic as the intermediates can be used in other anabolic pathways</p>

Question 29

<p>What does amphilbolic mean?</p>

Answer 29

<p>Serves both catabolic and anabolic processes</p>

Question 30

<p>What can the citric acid cycle make building blocks for when energy levels are okay?</p>

Answer 30

<p>Nucleotide bases</p>

<p>Heme groups</p>

<p>Proteins</p>

Question 31

<p>What is a problem with intermediates of the citric acid cycle being used elsewhere?</p>

Answer 31

<p>Can lead to a deficiency of the intermediates, stopping the citric acid cycle and the generation of energy</p>