November 24, 2016

Biology: Respiration

During respiration, cells break down simple food molecules such as glucose and release the energy they contain.

C6H12O+ 6 O2 6 CO+ 6 H2O + energy

The first stage of respiration, which takes place in the cytoplasm, releases a small amount of energy. The second stage takes place in the mitochondria. A large amount of energy is released at this stage.

Photosynthesis and respiration can be thought of as opposite processes. Together, these two processes form a cycle that keeps the levels of oxygen and carbon dioxide fairly constant in the atmosphere.


CO2 + H2→ sugars + O
glucose + O→ CO2 + H2O

Fermentation, an energy-releasing process that does not require oxygen. Fermentation provides energy for cells without using oxygen. The amount of energy released from each sugar molecule during fermentation, however, is much lower than the amount released during respiration.

Alcoholic Fermentation 
Occurs in yeast and other single-celled organisms products: alcohol, CO2, small amount of energy

Takes place in the body. Cells lacking oxygen, used the process of fermentation to produce energy. Lactic acid is produced.