EXAM 3-Citric acid Cycle

The citric acid cycle is the

third stage of glucose metabolism

the citric acid cycle is cyclical because

a series of organic molecules are regenerated with each turn of the cycle

The cycle results in the breakdown of

carbohydrates to carbon dioxide

How many steps are there?

8

The first step

the acetyl group (2 carbons) is removed from is removed from acetyl CoA and attached to oxaloacetate(4 carbons) to form citrate(6 carbons).

citrate is also known as

citric acid

step 2

citrate is rearranged to an isomer called isocitrate

step 3

isocitrate is oxidized to alpha-ketoglutarate, releasing CO2 and forming NADH

step 4

a-ketoglutarate is oxidized and combines with Co-A to form succinyl CoA. Co2 is released and NADH is formed again

step 5

succinyl CoA is broken down to CoA + succinate. Drives the synthesis of GTP, transfer its phosphate to ADP, FORMING ATP

Breaking down succinnyl CoA to CoA + Succinate is what type of reaction?

exergonic

step 6

succinate is oxidized to fumarate and FADH2 is made

step 7

fumarate combines with water to make to make malate

step 8

malate is oxidized to oxaloacetate, NADH is made, cycle repeats