Respiration in Providing Energy for the Activities of the Cells

 

SCIENCE_BIOLOGY

Respiration in Providing Energy for the Activities of the Cells

Introduction

Human body is made up of cells. Cells are microscopic in structure capable of performing several functions. So cells are regarded as the basic and functional unit of life. It needs energy to perform several functions. Oxygen serves as a fuel to liberate energy in this case. This oxygen is supplied through the help of Red Blood Cells(RBC). Oxygen gets dissolved with RBC in the lungs. Hence the lung is regarded as the main respiratory system of the human body. The process of releasing energy in the form of ATP (Adenosine Triphosphate) by breaking the food with help of oxygen at the cellular level is called respiration. During respiration energy, water and carbon dioxide are released. Carbon dioxide is regarded as the byproduct and thrown out from the body.

Steps in Respiration:

For a simple understanding respiration means to take in oxygen and release carbon dioxide, in fact it is a complicated process and involves following steps.

1. Breathing(inhaling and exhaling of gas)

2. Gaseous exchange

3. Transport of gas

4. Exchange of gas between blood cells and cells

Breathing process involves taking in oxygen and throwing out carbon dioxide. Diaphragm plays an important role during inhaling of oxygen and exhaling of carbon dioxide. During inhaling of oxygen gas diaphragm is expanded, pressure inside the lung cavity is reduced and maximum amount of air enters inside it. During the exhalation process the diaphragm is contracted, pressure of the lung cavity gets increased and carbon dioxide gas is thrown outside.

Inside the lungs there are numerous minute air sacs like structures called alveoli. Alveoli are the site for the exchange of gases in the lungs. While inhaling oxygen the concentration of oxygen gas is more than the concentration of oxygen gas in the RBC so the oxygen gas gets diffused in the blood. Similarly the concentration of carbon dioxide gas is maximum in the blood vessels and gets diffused in the alveoli. Such exchange of gases in the lungs is called pulmonary exchange of gases.

Once the oxygen is dissolved in the blood it goes to the heart through pulmonary vein and it is pumped to several organs through the help of aorta. The blood rich with oxygen gas now reaches to the deep layer of cells through the help of capillaries. Here the concentration of oxygen is more than the cells and is diffused inside. The oxygen gas is utilized by the cells to break down the simple form of food. After the combustion of food energy is produced. Water and carbon dioxide gas are formed as a by-product. The concentration of carbon dioxide gas is more in the cells and is diffused in the blood cells which is ultimately taken to the lungs. Finally the maximum concentration of carbon dioxide gas will be exhaled from our body.