Chapter 9, Problem 46A

Summary Introduction

To discuss:

The importance of enzymes in living organisms

Introduction:

A catalyst is a substance that lowers the activation energy needed to start a chemical reaction. A catalyst can speed up a chemical reaction. It does not get used up in the reaction. There are many types of catalysts that are used by scientists to speed up reactions. A catalyst can be used multiple times as it does not get spent in the chemical reaction.

Answer to Problem 46A

Enzymes are bio catalysts that are very important to life. They work by lowering the activation energy needed to start a chemical reaction. Without enzymes reactions would occur at a very slow rate. When an enzyme acts as a biological catalyst, the reaction occurs at a rate that is useful to cells. Many biological processes like digestion, photosynthesis, respiration, etc. occur in the presence of enzymes.

Explanation of Solution

Enzymes are bio catalysts that speed up the rate of chemical reaction in biological processes. They are very important to life. Enzymes are also not used up in the reactions so they can be used again. Factors like pH, temperature, and other substances affect the activity of enzyme. They are highly specific in their action. Enzymes work by forming an enzyme- substrate complex which helps in breaking the chemical bonds in reactants and forming new bonds. The substrates react to form new products.

Enzymes affect many biological processes. Examples are:

• Amylase is an enzyme that catalyzes the breakdown of amylose.
• When a person is bitten by a poisonous snake, enzymes in venom break down the membranes of red blood cells of the person.
• Green apples ripen due to action of enzymes.
• Many enzymes are used in photosynthesis and cellular respiration which provide energy for the cellular activities.