chemistry of enzymes

Major Concepts:
A. To study what are enzymes, their general properties and classification.
B. To learn the mechanisms of enzyme catalysed reactions and various factors affecting enzyme activity.
C. To learn various types of enzyme inhibition and how the enzyme activity is regulated.
Specific Objectives:
A. 1. Define enzyme.
2. What is meant by catalytic activity of enzymes?
3. Note that enzymes are protein in nature.
4. Learn what coenzymes are.
5. Study the role of metal ions in enzymes.
6. Study the nomenclature and classification of enzyme as approved by International Union of Biochemistry (IUB). Learn at least two examples from each class.
B. 1. Know what is enzyme catalysed reaction and how an enzyme functions by lowering the energy of activation.
2. Define specificity of enzyme and learn different types of specificity.
3. Study Lock-and-Key theory and induced fit theory of mechanism of action of enzymes.
4. Learn various factors that affect the activity of enzyme, such as, pH, temperature, substrate concentration, enzyme concentration, product concentration, presence of inhibitors or activators.
5. Know the Michaelis-Menten equation and significance of each term.
6. Know the importance and application of double reciprocal or Lineweaver-Burk plot and calculate enzyme velocity when S >> Km, S = Km and S << Km.
C. Learn what is enzyme inhibition and various types of inhibition.
1. Nonspecific inhibition: List the various agents responsible for it.
2. Competitive inhibition.
3. Noncompetitive reversible inhibition, and noncompetitive irreversible inhibition.
4. Make a tabular form to show the difference between competitive and noncompetitive inhibition.
5. Learn examples of competitive inhibition in biological system: Clinically used drugs.
6. Study the various mechanisms by which enzyme activity is regulated, study allosteric enzyme.
7. Learn about control of enzyme degradation: Ubiquitin-protease pathway.

INTRODUCTION
Enzymes are another important group of biomolecules synthesized by the living cells. They are catalysts of biological systems (hence are called as biocatalysts), colloidal, thermolabile and protein in nature. They are remarkable molecular devices that determine the pattern of chemical transformations. They also mediate the transformation of different forms of energy. The striking characteristics of enzymes are their catalytic power and specificity. Actions of most enzymes are under strict regulation in a variety of ways. Substances on which enzymes act to convert them into products are called substrates.
Catalytic Activity of Enzymes: Enzymes have immense catalytic power and accelerate reactions at least a million times, by reducing the energy of activation. Before a chemical reaction can occur, the reacting molecules are required to gain a minimum amount of energy, this is called the energy of activation. It can be decreased by increasing the temperature of the reaction medium. But in human body which maintains a normal body temperature fairly constant, it is achieved by enzymes.