1) Photosynthesis is a very important biological process when the light energy is transformed into chemical energy by the living organisms. Sun energy is used by plants and bacterias to produce sugar which later will be converted to ATP by cellular respiration. In the process of respiration, glucose is broken into carbon dioxide and water. Photosynthesis requires the products of respiration while respiration requires the product of photosynthesis. The above mentioned processes can control the concentration of carbon dioxide and oxygen. Moreover, the energy is stored in the cells. Two reactions take place during photosynthesis – Light reaction and Calvin cycle. First, light energy is converted to chemical energy. The sun light – to ATP, ATP – to chloroplast for production chemical energy and to convert CO2 into sugar. During glycolysis the energy goes from sugar to the cell. (Audesirk et al., 2008, p.26)
2) Fermentation allows respiration to take place without oxygen. Moreover, due to the process of fermentation the cells take energy from glucose. There may be different reactions of fermentation. They depend on the sugar which is used in this process and the product which is produced. For example, glucose as sugar and ethanol as product. (Lawlor, 2001, p.112)
3) Enzymes play an important role in a number of biochemical reactions. Three major steps of the cycle of enzime-substrate interactions are the next ones:
1. enzyme and substrate;
2. enzyme-substrate complex;
3. enzyme and product.
Enzyme activity is regulated by inhibitor molecule which can easily bind to enzyme at the opposite site. This molecule can alter the the shape of enzyme and the activity of enzyme will be reduced. (Lawlor, 2001, p.34)
Audesirk, T., Audesirk, G., Byers, B. (2008) Biology – Life on Earth with Psychology. 8-th Edition. San Francisco. CA: Benjamine Cummings.
Lawlor, D. W. (2001) Photosynthesis: Molecular, Physiological, and Environmental Processes. 3-rd Edition. BIOS Scientific Publishers.