User:Atcovi/Science/Cellular Respiration


 * See also Photosynthesis

Cellular Respiration is the process, taken place in the mitochondria, by which all living cells convert glucose (food) into ATP (energy).

The chemical equation for cellular respiration is as follows: "6O2 + C6H12O6 → 6CO2 + 6H2O + ATP" The chemical equation for cellular respiration is the opposite of the chemical equation for photosynthesis. The products and reactants are switched.

The chemical equation for photosynthesis is as follows: "6CO2 + 6H2O + energy from the Sun → C6H12O6 + 6O2"

Cellular respiration is split into two parts.

Anaerobic Respiration
The first part of cellular respiration is anaerobic respiration, from the French word anaérobie meaning "anaerobic". Anaerobic respiration does not require oxygen and takes place in the cytoplasm, and not the mitochondria. Glucose is broken down into carbon compounds, that can be used for Part 2 of cellular respiration (aerobic respiration). This process will give an organism 2 ATPs.


 * EXAMPLES OF ANAEROBIC RESPIRATION

Glycolysis
Glycolysis, from prefix -gylco (γλυκύς) and suffix -lysis (λύσις), both literally mean "sugars-breakdown", starts out with one molecule of glucose breaking down into 2 molecules of pyruvic acid. 2 ATP and 2NADH are also created in this process.

Alcoholic Fermentation

 * Fermentation: Fermentation is a metabolic process in which an organism converts a carbohydrate, such as starch or a sugar, into an alcohol or an acid.

Plants, yeast, some microorganisms break down pyruvic acid without oxygen to make 2 ATP and alcohol.

Lactic Acid Fermentation

 * Fermentation: Fermentation is a metabolic process in which an organism converts a carbohydrate, such as starch or a sugar, into an alcohol or an acid.

Animals (muscle cells) will break down pyruvic acid without oxygen to make 2 ATP and lactic acid.

Aerobic Respiration
Aerobic respiration, with oxygen (world's most powerful electron acceptor), follows after glycolysis and takes place in the mitochondria. An organism will gain a total of 34 ATPs. Aerobic respiration is split into 2 parts:
 * 1) Krebs Cycle, also known as Citric Acid Cycle
 * 2) Electron Transport Chain, or ETC

Krebs Cycle
The Krebs Cycle, occurring in the matrix of the mitochondria, uses the carbon compounds created by glycolysis to create hydrogen ions that will later be used in ETC. 2 ATPs are created.

Electron Transport Chain

 * Also known as "ETC"

ETC, taking place in the cristae in mitochondria, takes the hydrogen ions from the Krebs Cycle to create ATP. These ions are "bounced" through the ETC so that an organism can extract as much ATP as possible. Organisms such as you "breathe" oxygen so that it will bond with the hydrogen ions once they are used. If you put these two things together, you get water. A total of 32 ATPs are created.

Summary

 * The point of cellular respiration is to take glucose and turn it into ATP than an organism can use.
 * Total number of ATP from glycolysis = 2
 * Total number of ATP from aerobic respiration = 34
 * Total number of ATP: 36