Ch. 5 - Enzymes

Enzymes are protein catalysts which help in the breakdown of biological molecules without getting used up.

• Enzymes don’t start processes, they just speed them up • Enzymes can be reused

Carbohydrates - carbohydrases Proteins - proteases Lipids - lipases

Starch - amylase Maltose - maltase Sucrose - sucrase Hydrogen Peroxide - catalase

Starch (polysaccharide), with the help of salivary amylase is broken down to maltose. Maltose (disaccharide), with the help of maltase is broken down into glucose (monosaccharide).

A substrate is the substance which binds with the enzyme.

Enzymes have an opening in their shape, which is known as an active site. The shape of the active site is exactly complimentary to the shape of its substrate. The substrate binds with the enzyme through the active site, creating the enzyme-substrate complex. The enzyme then assists in the reaction taking place by speeding it up until the products form and the enzyme-product complex is created. The products then leave the enzyme and the enzyme can be used again.

When an enzyme is denatured, the shape of its active site changes and thus substrates will not be able to bind to the active site, and reactions will not take place,

• Temperature • pH Levels Each enzyme has its own optimum temperature and pH, and post that the enzyme gets denatured.

Optimum temperature/pH means the temperature/pH at which the enzyme works most efficiently and the rate of reaction is the highest.