Week 9 Flashcards
(30 cards)
What is the mnemonic for the citric acid cycle?
Can I keep selling seashells for money officer
What is step 1 of the CAC?
Acetyl CoA joins oxaloacetate to form citrate
What is step 2 of the CAC?
Citrate is converted to isocitrate
What is step 3 of the CAC?
Isocitrate is oxidized to alpha-ketoglutarate, CO2 leaves, 1 NADH is formed
What is step 4 of the CAC?
Alpha-ketoglutarate is oxidized to succinyl CoA, CO2 leaves, 1 NADH is formed
What is step 5 of the CAC?
Succinyl CoA turns into succinate, thioester bond is cleaved, 1 ATP formed
What is step 6 of the CAC?
Succinate is oxidized to fumarate, 1 FADH2 is formed
What is step 7 of the CAC?
Water is added to fumarate, converting it to malate
What is step 8 of the CAC?
Malate is oxidized to regenerate oxaloacetate, 1 NADH is formed
What are the products of one turn of the CAC?
3 NADH, 1 FADH2, 1 ATP, 2 CO2
What are the two regulatory enzymes of the CAC?
Isocitrate dehydrogenase, alpha-ketoglutarate dehydrogenase
What are the positive effectors of isocitrate dehydrogenase?
ADP, NAD+
What are the negative effectors of isocitrate dehydrogenase?
NADH, ATP
What are the positive effectors of alpha-ketoglutarate dehydrogenase?
ADP, Ca2+
What are the negative effectors of alpha-ketoglutarate dehydrogenase
NADH, ATP, Succinyl CoA
What are the enzymes involved in CAC, starting from step 1?
Citrate synthase, aconitase, isocitrate dehydrogenase, alpha-ketoglutarate dehydrogenaze complex, succinyl CoA synthetase, succinate dehydrogenase, fumarase, malate dehydrogenase
Where does CO2 leave in CAC?
Step 3, 4
Where is NADH formed?
Step 3, 4, 8
Where is ATP formed?
Step 5
Where is FADH2 formed?
Step 6
Where does the CAC occur?
Mitochondrial matrix
Describe what citrate synthase does
Couples acetyl-CoA to oxaloacetate and then hydrolyzes the resulting product, forming citrate and CoA-SH
How is citrate synthase regulated?
Negative feedback from ATP, NADH, Succinyl-CoA, and Citrate
Describe what aconitase does
Isomerizes citrate to isocitrate
