Cellular Respiration is the process of breaking down glucose into energy and other products. This provides ATP to the cell, giving energy. 

Aerobic Cellular Respiration is comprise♙-CoA, Citric Acid Cycle (also known as the Krebs Cycle), and the Electron Transport Chain.

Anaerobic Cellular Respiration is comprised of two parts: Glycolysis, and either Alcoholic Fermentation or Lactic Acid Fermentation.


Aerobic Respiration
Glucose + Oxygen --> Carbon Dioxide + Water + Energy
C6H12O6 + 6O2 --> 6CO2 + 6H2O + ATP

Aerobic Cellular EEEEdit

Glucose is broken down into two pyruvate in glycolysis, which then drops a hydrogen to become Acetyl-CoA. Acetyl-CoA begins the Citric Acid Cycle, which is subatomically modified, losing several electrons in the rearrangement of molecules to the Electron Transport Chain. The Electron Transport Chain, (ETChain), then produces ATP, which then goes to provide the activation energy for glycolysis to begin.

Glycolysis Edit

It's a 10-reaction biochemical pathway designed to extract energy from Glucose. Glycolysis uses Glucose as the starting material, and produces NADH, Pyruvate, and ATP as the end product.

Glucose is oxidized, with two NAD+ taking 2 electrons from one glucose to form to two NADH molecules. Two ATP molecules give up their phosphates to become ADP, providing energy to drive the reactions in glycolysis. However, in the end, 4 ATP molecules are produced, so there is a net gain of 2 ATP. After the series of chemical reactions, 2 pyruvic acids are produced. Thus, glycolysis results in the formation of 2 NADH, 2 Pyruvates, and 4 ATP molecules (with 2 of these ATP molecules recycled to drive glycolysis though).

Formation of Acetyl-CoAEdit

Sometimes combined with the Citric Acid Cycle as one step, this utilizes pyruvate and removes a hydrogen. It is given to Nicotinamide Adenosine Dinucleotide to create Nicotinamide Adenosine Dinucleotide Hydrogen. The pyruvate releases carbon dioxide and the Coenzyme A remains with two carbons. This is Acetyl-CoA and it is ready for the CACycle.


Electron Transport Chain Edit

Occuring in the mitochondrierl inner membrane, FADH2 molecules and NADH molecules release their electrons on an electron transport chain. The cytochrome complexes and electron carrier proteins transport electrons in a series of redox (reduction) reactions. As these electrons move along this chain, energy is produced, which is used to pump from the brain space into the mitochondrial matrix, creating a proton gradient. With this important protons can diffuse back into the matrix via passive transport through an enzyme called ATP synthase, combining ADP with Phosphate groups to form ATP. The use of a proton gradient and ATP synthase to generate ATP is called chemisomosis.

Oxygen becomes the final electron acceptor, catching electrons somewhere along the Electron Transport Chain. With electrons, oxygen, and protons (H+), water is formed. Edit

For every FADH2 molecule that gives up its electrons, 2 molecules of ATP are produced. For every NADH molecule that gives up its electrons, 3 molecules of ATP are produced. This is because NADH molecules donate their electrons towards the "beginning" of the chain, so their electrons have more time to produce more energy for the proton gradient. FADH2 molecules donate their electrons farther down the chain, so their electrons have less time to produce energy for the proton gradient.

Anaerobic Cellular RespirationEdit



The process of glycolysis in anaerobic respiration is the same as it is during aerobic respiration (See "Glycolysis" under Aerobic Respiration................................. 2 molecules of NADH (by adding electrons to NAD")  are formed, and 4 ATP molecules are generated (but 2 of those ATP molecules are recycled to continue the process of glycolysis, leaving a net generation of 2 ATP's).

Note that ATP and NAD+ are both key molecules that are required for glycolysis to occur


Alcoholic FermentationEdit