The basic process of cellular respiration - three steps, where they happen, what are inputs and outputs of process, what is oxidized ?and what is reduced?
Cellular respiration is the process through which organic compounds are broken down enzymatically in the mitochondria to release energy. The reaction involves oxidation of oxygen to carbon dioxide and water and reduction of glucose. The main inputs are oxygen and glucose and outputs are carbon dioxide, water and ATP.
Cellular respiration is the break down of glucose into energy yielding compounds such as ATP and byproducts like carbondioxide and water. The three processes are:
Glycolysis
Kreb's cycle/Citric acid cycle/TCA cycle
Electron transport chain
Explanation:
Glycolysis:
Glycolysis, a process that occurs in the cytoplasm, entails the break down of glucose into two molecules of pyruvate.
In each glycolytic pathway, glyceraldehyde 3-phosphate dehydrogenase produces 1 molecules of NADH as a result of reduction of NAD+.
Their is a net gain of 2 ATP in glycolysis.
Pyruvate Oxidation:
Pyruvate dehydrogenase converts pyruvate to Acetyl CoA producing 1 molecule of NADH per pyruvate oxidized.
Kreb's Cycle:
Kreb's cycle, also called the TCA or citric aicd cycle, occurring in the  mitochondrial matrix, entails the oxidation of two Acetyl Co-A moleucules into 2 ATP, 2 molecules of CO2 and the following products:
In Kreb's cycle, isocitrate dehydrogenase, alpha-ketoglutarate dehydrogenase, and malate dehydrogenase reactions produce 1 molecule of NADH each. Furthermore, succinate dehydrogenase reaction produces a single molecule of FADH2 per FAD reduced.
Since, we began with 2 molecules of glyceraldehyde 3-phosphate, we multiply the above figures by 2 and get a total of 10 NADH and 2 FADH2.
Electron Transport Chain:
Electron Transport Chain (ETC) takes place on the inner mitochondrial membrane. Here, the NADH and FADH2 produced during the TCA cycle are converted into 36 ATP molecules.
An electrochemical gradient, created by the movement of protons (H+) across the mitochondrial membrane activates the enzyme ATP synthase that phosphorylates ADP into ATP. This process is called chemiosmosis.
The final proton acceptor in the electron transport chain is oxygen which is reduced by picking up two hydrogen ions, creating water molecules.
