THE KREBS CYCLE

Where does it occur?

Mitochondrial matrix

Step 1

Acetyl CoA splits, acetate combines with oxaloacetate, forming citrate- CoA reused in link reaction

Step 2

Citrate decarboxylated and dehydrogenated, releasing CO2- releases 2 hydrogen atoms used to reduce NAD, leaving a 5 carbon compound

Step 3

5 carbon compound is decarboxylated and dehydrogenated again, releasing CO2 and reducing another NAD- produces 4 carbon compound

Step 4

First 4 carbon compound converted into another 4 carbon compound, regenerating a molecule of ATP by substrate level phosphorylation

Step 5

Next 4 carbon compound is dehydrogenated- releases 2 hydrogen atoms which reduce FAD, producing FADH2 and a different 4 carbon compound

Step 6

Final 4 carbon intermediate is converted to oxaloacetate by dehydrogenation, producing a molecule of NADH

Products (for 1 glucose)

4 CO2, 6 NADH, 2 FADH2 and 2 ATP