The krebs cycle
The tricarboxylic acid cycle (TCA cycle)
GROUP 9
THE KREB CYCLE
PRESENTATION BY:
NELONDO
219073627
NANGOLO
219147132
NASHONGO 220074836
NDARA
220033765
NEHALE
219151679
NEKANDU
219024766
What is a kreb cycle?
The kerb cycle is known as a series of chemical reactions that are used by all
aerobic organisms to generate energy through the oxidation of acetate.
• derived from carbohydrates, fats, and proteins—into carbon dioxide.
• The Krebs cycle is the second stage of cellular respiration.
The kreb cycle process
• The Krebs cycle is aerobic and takes place in the
mitochondrial matrix.
• It starts by breaking down three-carbon molecules from
glycolysis
• https://images.app.goo.gl/v8Liyj7BpPsVmc9y7
The process
• Each pyruvate loses one carbon and makes a two carbon molecule called
acetyl CoA.
• The lose carbon joins with the oxygen that we breath in and forms a carbon
dioxide.
• The Acetyl Co-A then diffuses into the matrix of the mitochondria.
• In the matrix, the pyruvate is modified in series of the following steps:
The steps of the pyruvate oxidation in the
matrix
Step 1
A carboxyl group is snipped off of pyruvate and released as
a molecule of carbon dioxide, leaving behind a two-carbon
molecule.
Step 2
The two-carbon molecule from step 1 is oxidized, and the
electrons lost in the oxidation are picked up by NAD+ to form
NADH.
Step 3
The oxidized two-carbon molecule, (an acetyl group
highlighted in green)is attached to Coenzyme A( CoA).
An organic molecule derived from vitamin B5, to form
acetyl CoA. Acetyl is sometimes called a carrier
molecule, and its job here is to carry the acetyl group to
the citric acid cycle.
The steps above are carried out by a large enzyme complex called the pyruvate dehydrogenase complex, which
consists of three interconnected enzymes and includes over 60 subunits