Diagram of Cellular Respiration
The following diagram of cellular respiration will help you understand the above given process of cellular respiration better.
http://www.buzzle.com/articles/cellular-respiration-diagram.html
Explanation for the Simple Cellular Respiration Diagram
The break down of glucose molecule takes place when carbon is oxidized and oxygen is reduced. Thus, the cellular respiration process is an oxidation-reduction reaction. The process of respiration is divided in two major steps, that is, glycolysis and aerobic cellular respiration. The glycolysis reaction leads to production of only two ATP molecules in absence of oxygen. The other 34 ATP molecules are produced due to the aerobic reaction in presence of oxygen.
Both plants and animals carry out the process of respiration but only plants proceed to another process that is, photosynthesis. The process of cellular respiration begins in the cytoplasm of the cells and is completed in the mitochondria as you can see in the above given simple cellular respiration diagram. The simple sugar molecules are broken down to energy or ATP molecules. You can read more on:
•Photosynthesis and Cellular Respiration
•Cellular Respiration in Plants
Glycolysis can take place under aerobic and anaerobic cellular respiration conditions. The glucose molecule is broken down into pyruvic acid or pyruvate in a series of chemical reactions. The pyruvate molecule acts as an intermediate between two processes, that is, glycolysis and Kreb's cycle. You can observe both these processes in the above given diagram for cellular respiration.
The Kreb's cycle or the tricarboxylic acid cycle begins when the pyruvate molecule moves to mitochondria from the cytoplasm. You can observe it in the diagram of cellular respiration given above. Here, the pyruvate is transformed and combined with coenzyme A. This produces a new molecule acetyl CoA. After a series of reactions, six CO2 molecules and two ATP molecules along with acetly CoA fragment are produced.
After successful completion of the Kreb's cycle, begins the electron transport chain as you can see in the simple cellular respiration diagram. This is also known as the oxidative phosphorylation process. Electrons are passed from the organic acids of Kreb's cycle to the electron acceptor as observed in the diagram for cellular respiration. This electron acceptor is the nictotinadenine dinucleotide (NAD). After a series of chain reaction in electron transport, energy is transferred to the electron carriers like the NADH and FADH2. Thus, finally leading to the production of ATP molecules.
Summary of the Total ATP Yield
The following total ATP yield are per glucose molecules as observed in the simple celluar respiration diagram:
•Glycolysis: Glycolysis yeilds 2 ATP and 4 NADH molecules. The 4 NADH molecules are later converted in the mitochondria into 4 ATP molecules. (Sometimes there may be production of 8 ATP molecules.)
•Acetyl CoA: The formation of Acetyl CoA yields 2 NADH molecule. These 2 NADH molecules are converted to 6 ATP molecules in the mitochondria.
•Kreb's Cycle: The Kreb's cycle yields 6 NADH, 2 FADH2 AND 2 ATP molecules. The 6 NADH are converted to 18 ATP molecules and 2 FADH2 molecules are converted to 4 ATP molecules.
Thus, the total ATP yield in the cellular respiration process is 36 or 38 ATP molecules.
I hope this article on simple cellular respiration diagram has helped you understand the process of respiration. The process of cellular respiration is a very complex reaction that involves many enzymes, coenzymes and molecules. Each and every step is a series of complex chemical reactions, that helps in the production of energy that is in the form of Adenosine triphosphate, that is, ATP.