Krebs Cycle (College Board AP® Biology)
Study Guide
Written by: Phil
Reviewed by: Lára Marie McIvor
The Krebs Cycle
The Krebs cycle (sometimes called the citric acid cycle) consists of a series of enzyme-controlled reactions in the matrix of the mitochondria
The process is as follows
2 carbon (2C) Acetyl CoA enters the circular pathway from the end of first stage of pyruvate oxidation
The pathway releases carbon dioxide, ATP, NADH and FADH2 from a series of organic intermediates
Finally the initial organic molecule is regenerated to allow the cycle to begin again
The products of the Krebs cycle are then used as follows:
Carbon dioxide is released as a waste product
NADH and FADH2 are transferred to the electron transport chain where they provide electrons to drive a series of REDOX reactions
The Krebs Cycle Diagram
The Krebs Cycle uses acetyl CoA from the oxidation of pyruvate to produce NADH, FADH2 and ATP. CO2 is lost as a waste product
Examiner Tips and Tricks
The Krebs cycle is often referred to as cyclical or circular. This is because the first organic molecule is regenerated throughout the reaction so that it can start all over again.
Note that you are not expected to know details of the steps of the Krebs cycle or the names of the intermediate molecules
Last updated:
You've read 0 of your 5 free study guides this week
Sign up now. It’s free!
Did this page help you?
