cellular respiration + photosynthesis?

Question

Can someone please give me a good explanation of the entire process of cellular respiration. All of the processes within it too, like glycolysis and all of those.

Answer 1

Cellular respiration is similar in most organisms, from simple one-celled bacteria, amoebas, and diatoms to complex plants like trees, and large animals such as elephants, whales, and human beings (see also Metabolism; Photosynthesis). In most organisms apart from prokaryotes (chiefly bacteria and blue-green algae) cellular respiration takes place in the tiny sausage-shaped organelles within the cell called mitochondria.

In fact there are two versions of cellular respiration (both described in more detail in their separate articles, Aerobic Respiration, and Anaerobic Respiration). Aerobic respiration requires oxygen to break down high-energy fuel molecules—typically a simple sugar such as glucose (blood sugar)—through a series of chemical stages. The results are carbon dioxide, water, and energy in the form of molecules of ATP—the cell’s standard energy-carrier. The biochemical stages in the breakdown of glucose form a circular pathway or cycle known as the Krebs cycle or citric acid cycle.

The Krebs cycle is active in all animals and higher plants and in most bacteria. In organisms that have cells with nuclei, the cycle is contained within a membrane-bound organelle called the mitochondrion, a structure often referred to as the power plant of the cell. The discovery of the cycle is credited to Sir Hans Adolf Krebs, a British biochemist who outlined its essential steps in 1937. This information had an enormous impact on both the understanding of cellular respiration and biochemical pathways in general. The Krebs cycle is also known as the tricarboxylic acid cycle from the types of chemicals involved, and the citric acid cycle because citric acid is one of the main components of the pathway.

Each of the individual steps in the process of glycolysis is controlled by an enzyme, and these enzymes are sensitive to various substrates and products of the reaction, giving a greater or lesser degree of control. But there is one enzyme which is worth particular mention. Catalysing one of the early “pump-priming” reactions, phosphofructokinase is an allosteric enzyme which is affected by the concentrations of its own substrates. It is inhibited by high levels of ATP and citrate, so that when there is plenty of ATP or the components of the Krebs cycle begin to build up, the whole process of glycolysis is slowed down. In changing the rate of glycolysis the rate of the whole process of cellular respiration is in fact controlled.

The enzyme is stimulated by high levels of ADP and AMP (adenosine monophosphate) or low levels of ATP and citrate, thus ensuring that when the cell needs energy and the components of Krebs cycle are low, glycolysis is speeded up to remedy the situation.

U can also try wikipedia if u're still having trouble with the topic.

Answer 2

Cellular Respiration consist of glycolysis, tricarboxylic acid cycle and electron transport chain.

Glycolysis: http://web.indstate.edu/thcme/mwking/glycolysis.html
Kreb's Cycle: http://wine1.sb.fsu.edu/krebs/krebs.htm
Electron Transport Chain: http://www.elmhurst.edu/~chm/vchembook/596electransport.html

If you think this is too tough, you can always go to wikipedia.

Answer 3

This process can be very simple or very detailed, depending on your level. Start here:

http://staff.jccc.net/PDECELL/cellresp/respintro.html#glycolysis

or http://www.phschool.com/science/biology_place/biocoach/cellresp/intro.html has nice pictures, etc.