A presentation on enzymes how they function

A presentation on enzymes

1. Enzymes Presented by Akshat Vats Roll No. – 16

2. Characteristic Of Enzymes i . Almost all enzymes are proteins. Enzymes follow the physical and chemical reactions of proteins. ii. They are heat labile. iii. They are water-soluble. iv. They can be precipitated by protein precipitating reagents (ammonium sulfate or trichloroacetic acid). v. They contain 16% weight as nitrogen.

3. Classification of Enzymes When early workers isolated certain enzymes, whimsical names were given. Some of these, such as Pepsin, Trypsin, Chymotrypsin, etc. are still used. Later, it was agreed to call the enzymes by adding the suffix "- ase " to the substrate. Thus, enzyme Lactase acts on the substrate lactose, and the products glucose and galactose are formed. These are known as the trivial names of the enzymes

4. IUBMB System of Classification International Union of Biochemistry and Molecular Biology (IUBMB) in 1964, (modified in 1972 and 1978), suggested the IUBMB system of nomenclature of enzymes. It is complex and cumbersome ; but unambiguous. As per this system, the name starts with EC (enzyme class) followed by 4 digits. First digit represents the class Second digit stands for the subclass Third digit is the sub-sub class or subgroup Fourth digit gives the number of the particular enzyme in the list. The enzymes are grouped into following Seven major classes

5. CLASS NAME FUNCTION EXAMPLE Class 1 Oxidoreductase Transfer of Hydrogen Alcohol Dehydrogenase Class 2 Transferase Transfer of group other than Hydrogen Hexokinase Class 3 Hydrolases Cleave Bond : Adds Water Acetylcholine Estrase Class 4 Lyases Cleave Bond without adding water Aldolase Class 5 Isomerase Intramolecular Transfers Triose Phosphate Isomerase Class 6 Ligases ATP Dependent Condensation of Molecule Acetyl-CoA Carboxylase Class 7 Translocases Transfer of Molecule across the membrane ATP-ADP Translocases