INTRODUCTION

You might have noticed that when you are hungry for a long time it is difficult for you to do hard work.

Even if you are able to do some hard work the rate at which you do that will be very low.

But when you are not hungry, the opposite happens. Does this mean that food helps us to work or carry physical activities? Yes it does, food releases energy when taken into the body by a process called respiration. Respiration is the process whereby energy is released from food by chemical processes to living organisms for their various activities with or without the presence of oxygen.