Cellular Respiration Grade 11 Notes

Summary:

Cellular respiration is a vital process in which cells obtain energy by combining oxygen and glucose, resulting in the release of carbon dioxide, water, and ATP. The mitochondria serve as the site for aerobic cellular respiration. Energy is essential for various life processes, including breathing, growth, movement, active transport, and maintaining body temperature. Energy exists in different forms, such as thermal, radiant, mechanical, electrical, chemical, and nuclear energy, with stored (potential) energy and working (kinetic) energy being the two types.

Aerobic cellular respiration consists of three stages: glycolysis, Krebs cycle, and oxidative phosphorylation. Glycolysis occurs in the cytoplasm and involves the breakdown of glucose into pyruvic acid, producing 2 ATP molecules. The Krebs cycle occurs in the mitochondria, where pyruvic acid is broken down into carbon dioxide and energy-rich hydrogen atoms. Oxidative phosphorylation occurs in the mitochondria as well, utilizing the energy from hydrogen carriers to produce ATP and forming water as hydrogen combines with oxygen.

In the absence of oxygen, anaerobic respiration occurs. Plant cells undergo fermentation, converting pyruvic acid into ethanol and carbon dioxide. Animal cells, lacking sufficient oxygen, switch to anaerobic respiration and produce lactic acid as glucose is incompletely broken down. Anaerobic respiration yields less ATP compared to aerobic respiration. Alcoholic fermentation and lactic acid fermentation are two forms of anaerobic respiration.

Aerobic respiration requires glucose and oxygen, while anaerobic respiration only requires glucose. The products of aerobic respiration are carbon dioxide and water, while ethanol and carbon dioxide or lactic acid are produced in anaerobic respiration. Aerobic respiration generates more ATP than anaerobic respiration. The applications of anaerobic respiration can be observed in various industries, including beer and wine production, bread baking, and cheese making.

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Cellular Respiration Grade 11 Notes

Grade 11 Life Sciences
Cellular respiration:
Respiration is the biochemical process in which the cells of an organism obtain energy by combining oxygen and glucose, resulting in the release of carbon dioxide, water, and energy (ATP).

The mitochondria are the site of aerobic cellular respiration in cells.

Cellular Respiration Grade 11 Notes