Introduction
All living creatures need food. The food is consumed so that energy is obtained. The energy is utilised by the body for various purposes like locomotion, conduction of impulses, repair of damaged tissues, building of cell materials, etc.
Respiration - Meaning
Respiration can be broadly defined as 'the breakdown of organic compounds into simpler compounds accompanied by the release of energy in the form of ATP.'
Respiration and Breathing
The oxygen taken in is used to break down the respiratory substrate (e.g., glucose) and energy is released along with carbon dioxide.
Stages of Respiration
The exchange of gases between the environment and the body is called external respiration or gaseous exchange.
Gaseous Exchange in Fish
Fish has specialised structures called the gills to carry out exchange of gases with water.
Gaseous Exchange in Human Beings
There are a pair of lungs in the thoracic cavity - the left lung and the right lung.
Breathing Mechanism
The physical movements associated with the gaseous exchange are called breathing. They are controlled by the respiratory centre of the medulla oblongata in the human brain.
Cellular Respiration
Glucose is a carbohydrate - a compound of carbon and hydrogen. The bonds between the carbon and the hydrogen atoms are very strong.
Types of Respiration - Aerobic and Anaerobic
Most of plants and animal cells respire aerobically, that is, in the presence of oxygen.
Significance of Respiration
Respiration is an important process in nature. It is a process by which the solar energy trapped by the plants in the food can be utilised. The organic compounds are broken down to release energy.
Summary
Breathing provides the mechanism necessary to take in oxygen and give out carbon dioxide that is a waste gas. It is a physical process and part of respiration. Respiration is a biochemical and physical process.
Question and Answers
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Multiple Choice Questions
