Question

Can someonee please explain the Krebs Cycle, glycolysis, and the electron transport chain? THANK YOU

Answer 1

Hello! Cellular respiration can be confusing in textbooks and in general, so I've explained it in my own words the best I can to simplify it. :)

To start off, all of these processes are part of cellular respiration, which is a process cells use to extract energy from food and convert it to ATP, or energy.

Glucose + Oxygen → Water + Energy (ATP)

Here are the steps of cellular respiration:

1. Glycolysis- This process occurs in the cytoplasm. Glycolysis breaks down one molecule of glucose, a six-carbon molecule, into two three-carbon molecules called pyruvic acid. This process also produces four molecules of ATP, however, two molecules of the ATP are used in glycolysis, which means there is a net gain of 2 ATP molecules.

In short: Glycolysis= 1 molecule of glucose to 2 molecules of pyruvic acid/pyruvate, and also produces produces 2 ATP

Pyruvic acid is necessary to the next step of cellular respiration, which is the Krebs cycle.

2. Krebs Cycle (Citric Acid Cycle)- This process takes place in the matrix of the mitochondria of the cell. Pyruvate combines with coenzyme A before it enters the cycle. During the conversion of pyruvate to acetyl co-A, carbon dioxide is produced. Two rounds of this cycle occurs per glucose molecule.

In short: Krebs= Pyruvate + coenzyme A = acetyl coA, releases CO2 during this process, 3 NADH, 1 ATP, and 1 FADH.

3. Electron Transport Chain- This process creates a concentration gradient between protons, creating energy during chemiosmosis. This process produces 34 ATP molecules.

I hope this helps, and let me know if you have any questions! ^-^