Question

What happens during the kerb cycle?

Answer 1

http://en.wikipedia.org/wiki/Citric_acid_cycle

Answer 2

-The pyruvates produced in glycolysis are converted to Acetyl CoA molecules, which enter the Krebs cycle.

-Acetyl-CoA combines with a four-carbon compound, forming a six-carbon compound and releasing CoA.

-CO2 (carbon dioxide) is released from the compound, making a five carbon compound. Electrons are transferred to NAD+, making NADH.

- CO2 is released from the five-carbon compound, making a four-carbon compound. One molecule of ATP is made, as is a molecule of NADH.

-The four-carbon compound is converted into a new four-carbon compound; electrons are transferred to FAD, making FADH2.

-The four-carbon compound is converted to the original compound that started the cycle. Another molecule of NADH is produced.

Overall, NADH and FADH2 are the electron carriers that have all the high energy electrons, ready to be donated in the next step of cell respiration. 2 ATP molecules are produced, and carbon dioxide was released.

Next, the electrons carried by NADH and FADH2 go through something called the electron transport chain; the electrons are donated through a chain, where they lose energy through every molecule it passes through. The energy is used to power hydrogen ions OUT of the mitochondria's inner compartments; this creates a concentration gradient, where the H+ ions diffuse back in. By diffusing back in, the carrier protein that it diffuses through makes ATP. On average, ETC makes 32 ATP. When the electrons are used up, they bind with hydrogen ions and oxygen molecules. This results in water- H2O. Oxygen is the final electron acceptor, and water is a waste product.