Question 1
Photosynthesis is the process by which green plants manufacture their own food using carbon IV oxide and water in the presence of sunlight. On the other hand, respiration refers to the process by which by which glucose is oxidised is the presence of enzymes to release energy. The process by which human beings obtain energy from the sun is linked to both respiration and photosynthesis. Green plants manufacture their own food by use of carbon IV oxide and water in the presence of sunlight. Human beings obtain the energy through feeding in food from the green plants. The plants occupy the first trophic level in the food chain. Therefore, since human beings occupy a lower level in the trophic level, human beings obtain energy by feeding on the green plants as shown in the following diagram.
Sun
Green plants (producers)
Human beings
Human beings acquire energy from the sun through the process shown above.
Question 2
Fermentation is a complex biochemical process by which electrons and hydrogen ions from the NADH produced during glycolysis are donated to an organic molecule. Even during fermentation, a process that occurs in the absent of oxygen, many cells use glycolysis to produce energy in the form of ATP. Fermentation enables the organism to produce energy even in the absence in oxygen. Fermentation leads to the production of NAD+. This in turn helps in keeping glycolysis going hence generating the energy for the cell.
Glucose glycolysis in cytoplasm ATP
The energy from the sun is converted to chemical energy through the following process: firstly, the energy from the sun is absorbed by green plants for photosynthesis. Green plants then convert the stored energy into chemical energy by forming carbohydrates by the atmospheric carbon IV oxide and water and releasing oxygen into the atmosphere.
Question 3
Enzymes are biochemical catalysts that speed up the rate of reactions. Enzymes are protein in nature and therefore always affected by extreme temperature and Ph among others. Enzymes are specific in nature; meaning that only a specific enzyme can catalyse a particular substrate. Enzyme catalyses biochemical reactions as outlined below. The action of the enzyme is determined by its shape which biologists refer to as the active site. When the active site is denatured or the shape of the active site is interfered with, then the action of the enzyme is lowered. Therefore, if the enzyme’s active site is not denatured, then the enzyme will speed up the reaction. On the other hand, if the active site is denatured, then the action of the enzyme is reduced significantly.
The three steps of enzyme action include:
The first step plus substrate; here the enzyme reacts with the substrate which it is to catalyse. For instance, sucrase enzyme reacts with the substrate sucrose.
The second step is enzyme- substrate complex; the first step leads to the formation of a complex as depicted in the following diagram.
Enzyme + Substrate Complex. So the enzyme reacts with the substrate to form a complex compound.
The third stage entails the decomposition of the complex compound to form products and enzyme as shown below.
Enzyme + substrate complex products + enzyme
The cell produces most of the enzymatic proteins such as RNA in very low quantities. The expressions of the proteins that produce enzymes are regulated by transcription factors. These factors ensure that the cell does not produce unnecessary enzymes.
References
Silverman R.B.(2002). Organic Chemistry of Enzyme-Catalyzed Reactions, Revised Edition.U.S.A: Academic Press.
Hopkins, W.G.(2009). Photosynthesis and Respiration.U.S.A: Facts On File, Incorporated.
Melchor, M. (2007). Introduction to Biology. Tarrytown: Rex Bookstore.
