GENERAL SCIENCE Nutrition and
Digestion Carbohydrates is starchy and rich in sugar. It is also called the fuel of the body. It is manufactured through the process of photosynthesis by the green plants. One gram of carbohydrate provides 4.1 Calorie energy.
Carbohydrates is converted in to Glycogen by Liver and stored in the Liver itself and muscles. Glycogen is not produced by the plants.
Types of Carbohydrates :
Monosacharides : Simplest form of carbohydrate and animals can derive energy in this form. Example – glucose (grape sugar), fructose (fruit sugar),galactose (soluble milk sugar)
Disacharides : It is formed by the hydrolysis of two molecules of
monosacharies. Example – maltose, sucrose, lactose.
Polysacharides : It is formed by the chains of monosacharides and difficult to digest. Example – cellulose, starch.
Fat is said to be the stock food of the body because they consume less space and do not absorb water. One gram of fat provides 9.3 Cal. Of energy. Some fats like groundnut oil, seasame oil or sunflower oil which contains high polyunsaturated fatty acid do not increase cholesterol level in blood greatly but coconut oil, butter, ghee and vegetable oils contain high proportion of saturated acid which increases cholesterol in blood greatly.
Proteins are made of amino acids which gives nitrogen to our body. Nitrogen can not be stored in the body so it should be included in our daily diet. Proteins are the largest molecule in the nature and are responsible for manufacturing of enzymes, hormones, antibodies.
Out of 23 amino acids 10 amino acids are known as essential amino acids. Adults need 8 and children need 9 essential amino acids.
Digestion changes carbohydrates into glucose, fructose fats into fatty acid and glycerol and proteins into amino acids. These products are absorbed in the walls of intestine which contains finger type structures called villi .More than 50% of the energy comes from carbohydrates. A normal person requires about 70 gm of protein and 400 to 450 gm of carbohydrates.
Amino acids and monosacharides sugar are absorbed easily in to the blood capillaries of the villi. Fatty acid and glycerol passed in to the lymph capillaries of the villi. Amino acids go to the blood and from there go to the liver.
The concentration of the sugar in blood is 90mg/100 ml. When excess proteins are taken then they are converted in to glycogen and then fat. The deficiency of the protein may cause red haired.
About 70% of the body weight is water which is about 45 liters. The cells contain 30 lit. and blood plasma contain 3 lit .The remaining 12 liters fill the space between groups of cells.