Citric Acid Cycle - EXAM 3

Question 1

WHat is the gerneal overview of TCA cycle?

Answer 1

• Oxidizing Carbon fuels for harvesting High energy electrons (e-)
• It is amphibolic (i.e., catabolism and anabolism)
• Source of precursors for biosynthesis
• Takes place inside mitochondria
• Tricarboxylic acid cycle (TCA)
• Citric ACid cycle
• Krebs Cycle
• Oxifation of 2 carbons nits to produce
  
  • 2 CO2 molecules
  • 1 GTP
  • High energy electrons in the form of NADPH and FADH₂

Question 2

What is acetyle COA?

Answer 2

Question 3

How is converted acetyl CoA from Pyruvate

Answer 3

Question 4

How is aerobic gycolysis related to oxidative phophosylation?

Answer 4

Question 5

What Is the pyruvate dehydrogenase reaction?

Answer 5

Question 6

How is pyruvate dehydrogenase regulated?

Answer 6

Question 7

What are the key points of the TCA cycle

Answer 7

Question 8

Memorize this

Answer 8

Question 9

What is the first step of the TCA Cycle?

Answer 9

Question 10

What is the secon step of TCA cycle?

Answer 10

Question 11

What is the third sep of the TCA cycle?

Answer 11

Question 12

What is the fourth step of the TCA cycle

Answer 12

Question 13

What is the fifth step of the TCA cycle ?

Answer 13

Question 14

What is the 6th step of the TCA cycle?

Answer 14

Question 15

What is the 7th step of the TCA cycle?

Answer 15

Question 16

What is the 8th step of the TCA cycle ?

Answer 16

Question 17

How is the citric acid cycle regulated VIA PDH?

Answer 17

• High acetyl coa directly inhibts PDH complex subint E2
  
  • Energy charge dictates PDH complex activity. a high energy charge via NADH and ATp inhibit while ADP promotes
• Phosphate are also stimulated by CA2+ increases to initate muscle contraction

Question 18

What are the 3 sites of control in Citric acid cycle?

Answer 18

1. Citrate Synthase
   
   1. prevents wasteful hydrolysis of ACetyl coA
   2. oxaloacetate binds to the enzyme first then enzyme undergoes the configuration changes to accept acetylCoA
   3. Condensation reaction yirlds Citrate
2. Second control site is isocitrate dehydrogenase
   
   1. Allosteerically stimulated by Apd, enhancing enzyme affinty for substrate
   2. Reaction product, NADH also inhibits by directly displacing NAD+
3. THirds control site is Alpha-ketoglutarte dehydrogenase
   
   1. complex s similiar to PDH
   2. Allosterically inhibtied by its product succiyl Coa and NADH

Question 19

WHy is the TCa cycle so anaplerotic?

Answer 19