Biomolecules & Polymers Enzymes | California State University, Chico

University:
California State University, Chico
Course:
CHEM 370 | Organic Chemistry II
Academic year:

2022
Views:

17

Pages:

1
Author:

perlesdesfees9ovd

BIOMOLECULES & POLYMERS ENZYMES Proteins which are used as a catalyst in biochemical reaction is known as biocatalysts. SPECIFIC CHARACTERISTICS Enzymes have following two specific character as : (i) Specificity (ii) Efficiency Specificity of enzymes (a) Generally one enzyme can catalyze only one biochemical reaction. (b) It can increases rate of reaction upto 1020 times. (c) In some cases one enzyme can catalyzes more than one reaction and one reaction can be catalyzed by more than one enzyme. Ex. Enzyme present in Yeast (Zymase) can ferment both glucose and fructose into alcohol and also cane-sugar can be hydrolyses by invertase and sucrase enzymes. Efficiency of enzymes (a) One molecule of enzyme can convert millions of substrate molecules into product per second. Ex. Carbonic anhydrase enzyme present in red blood cells has a highest turn over number. (b) With having tertiary structure it can be collected as crystals. Enzymes are denatured at higher temperature. (c) Enzyme can be stored at low temperature as they are inactivated. Importance of enzymes In the thousands of enzymes presents in body if even a single enzyme would be absent or damaged than complex disease in results. Ex. Scarcity of Phenylalanine hydroxylase enzyme in human body is result in Phenylketonuria disease. Factors affecting enzyme action : (i) Optimum temperature and pH. Enzyme catalysed reactions have maximum rate at physiological pH of around 7.4 and human body temperature of 37ºC (310 K) under one atmosphere pressure. In fact, as the temperature or pH is increased, the rate rises to a maximum (at 37ºC or pH = 7.4) and then falls off. (ii) Enzyme activators (co-enzymes). The activity of certain enzymes is increased in the presence of certain substances, called co-enzymes. It has been observed that if a protein contains a small amount of vitamin as the + non-protein part, its activity is enhanced considerably. The activators are generally metal ions such as Na , 2+ 2+ 2+ Mn , Cu , Co etc. These metal ions are weakly bonded to the enzyme molecules and increase their + catalytic activity. For example, the enzyme, amylase, in presence of NaCl, which provides Na ion, shows a very high catalytic activity. (iii) Enzyme inhibitors and poisons. Just as in the case of catalysts, the activity of enzyme is slowed down in the presence of certain substance. Such substances are called inhibitors or poisons. They act by combining with the active functional group thereby reducing or completely destroying the catalytic activity of the enzymes. The use of many drugs is on account of their action as enzyme inhibitors in our body.