The way cells produce energy

ATP & Respiration: Crash Course Biology #7 – MIT edx video

Most of the Biomolecules that gives us energy are processed and end up as Glucose

Glucose + 6 Oxygen –> 6 Carbon dioxide + 6 Water + ATP (Energy)

Cellular respiration stages

Glycolysis

Breaking Glucose into two 3-carbon molecules, called Pyruvic acids, or pyruvate molecules. It also uses 2 ATPs, produces 4 ATPs. It also produces NADH

Uses many enzymes, like phosphoglucoisomerase.

It is an anerobic process, as it doesn't need oxygen. If there isn't oxygen the pyrovates undergo Fermentation. Anaerobic respiration can also produce lactic acid.

However, the next steps in cellular respiration are aerobic and require oxygen.

Krebs cycle

Happens inside inner membrane of the Mitochondria

Pyruvate molecules >> 2 ATP (per glucose) + Energy

First pyruvates are oxydized. One of the three carbons in the chain bonds with 2 oxygens, and leaves as CO₂. It leaves a 2-carbon compound called Acetyl coA (Acetyl coenzyme A)

Also an NAD+ picks up an H to form NADH

ATP

Form citric acid, from oxaloacetic acid and the Acetyl coA

There's more.... produce NADH and FADH₂

Electron transport chain

On membrane

ATP synthase