BIOMOLECULES AND ENZYMES

Detailed explanation-1: -The first model called the lock and key model, proposes that the shape and chemistry of the substrate are complementary to the shape and chemistry of the active site on the enzyme. This means when the substrate enters the active site, it fits perfectly, and the two binds together, forming the enzyme-substrate complex.

Detailed explanation-2: -An enzyme’s shape is determined by the sequence of amino acids in its structure, and the bonds which form between the atoms of those molecules. Why do enzymes have different shapes? Different types of enzymes have different shapes and functions because the order and type of amino acids in their structure is different.

Detailed explanation-3: -The specificity of an enzyme depends on its three-dimensional structure which is critical for its normal functioning. According to the lock-and-key hypothesis of enzyme action, the three-dimensional structure of the active site of an enzyme allows the enzyme to bind easily to specific substrates only.

Detailed explanation-4: -Because the enzyme and the substrate are at a close distance with weak attraction, the substrate must need a matching shape and fit to join together. At the active sites, the enzyme has a specific geometric shape and orientation that a complementary substrate fits into perfectly.

Detailed explanation-5: -The substrate simply fits into the active site to form a reaction intermediate. In this model the enzyme molecule changes shape as the substrate molecules gets close. The change in shape is ‘induced’ by the approaching substrate molecule.