Biology: Cellular Respiration

Cellular Respiration

Cellular Respiration is made up of three stages. The first stage is glycolysis and the word glycolysis means the splitting of sugar. Then during this process a six-carbon molecule is broken in half. After the six-carbon molecule is broken in half it forms two three carbon molecules. The second stage is the Citric Acid Cycle and the two molecules of pyruvic acid, the fuel that remains after glycolysis, is not ready for the citric acid cycle.

Also, the pyruvic acid must be converted to a form that the citric acid cycle can use. Next, the citric acid cycle finishes extracting the energy of the sugar by dismantling the acetic acid molecules. Afterwards the acetic acid joins a four-carbon molecule that later forms a six-carbon product called citric acid. Then two Co2 molecules eventually exit as a waste product. The third stage is the Electron Transport the chains are built into the inner membranes of the mitochondria. Those chains pump hydrogen ions across the inner mitochondrial membrane. The pumping causes the ions to become more concentrated on one side of the membrane than on the other side. The results of cellular respiration are that glycolysis and the citric acid cycle each contribute 2 ATP by directly making it.

When our muscles work, they require a constant supply of ATP which is generated by cellular respiration. Glycolysis does not require oxygen but does produce 2 ATP molecules for each glucose molecule broken down to pyruvic acid. Your cells must consume more glucose fuel per second, since so much less ATP per glucose molecule is generated under anaerobic conditions. this recycling of NAD cannot occur under anaerobic conditions because there is no O 2 to accept the electrons.

Instead, NADH disposes of electrons by adding them to the pyruvic acid produced by glycolysis. Muscle burn is due to the buildup of lactic acid in your muscles. Then Hill preformed a classic experiment that began with the observation that muscles produce lactic acid under anaerobic conditions. Individuals who are unable to accumulate lactic acid have muscles that fatigue more rapidly, which is the opposite of what you would expect.

Also, the changing view of lactic acid's role in muscle fatigue illustrates an important point about the process of science: It is dynamic and subject to constant adjustment as new evidence is uncovered. Our muscles cannot function by lactic acid fermentation for very long. However, the two ATP molecules produced per glucose molecule during fermentation is enough to sustain many microorganisms.


 By Miguel Martinez


Article Source: Biology: Cellular Respiration