NH2
RCH RCH(NH2)CO2 H
CO2 H
Carbohydrates
Like proteins carbohydrates are also absorbed into the body. When you eat a type of food that contains carbohydrates it is digested into the body and is turned into glucose. Glucose is used in the body as a source of fuel. These carbohydrate molecules are broken down into smaller molecules by enzymes in the saliva. The carbohydrates firstly enter and are broken down by enzymes and the saliva and the pancreas. The enzyme in the lining of the small intestine splits the molecule down and absorbs the glucose into the blood. The glucose that is converted from the carbohydrates is then carried out in the bloodstream in the liver and is stored in the body as energy which is provided for the body.
Carbohydrates help by providing energy to the body. Examples of carbohydrates are sugars, cellulose and starch. These are broken down into three different types of polysaccharides, monosaccharide and disaccharides.
C6 H12 O6 + 6 O2
Fibre
Like proteins and carbohydrates fibres are also broken down in the body. Fibres however, are not broken down by enzymes and can be present in food as soluble o insoluble fibres. Soluble fibres dissolve very easily in water and are like a soft gel like texture in the intestines. Soluble fibres reduce the speed of digestion and release energy such as carbohydrates; they also assist in keeping blood pressure low within the body. The insoluble fibres pass unchanged through the intestines. Fibres present in food are an indigestible substance. Fibres speed up the excretion of waste products that are produced by the body. If waste products in the body are not excreted then this will build up in the small intestine and could possibly cause another disease.
Lipids
Lipids, also known as fats are a very big source of energy for the body. Lipids are broken down in the body in a controlled way. Lipids firstly dissolve in the watery content of the intestine. The larger fat molecules are broken down into smaller molecules by the acid present in the liver. These smaller lipid molecules are known as fatty acids and cholesterol. In these cells the smaller molecules are then formed back into larger ones, these mostly pass into the vessels called lymphatic near the intestine. Lipids do not digest in water as they congeal together in large masses. This is when the bile produces a substance that comes from the liver and is also stored in the gallbladder. The fat is then carried to the different parts of the body.
Triglyceride
Water and Salt
Water that is given into the body is a substance that goes through the body into the small intestine, where the salt is dissolved. Water and salt comes through food and liquid that is digested into the body.
Vitamins
Vitamins are also present in many different types of food. These are absorbed through to the small intestine. There are two types of vitamins these are classified as water- soluble and fat- soluble vitamins. Water soluble vitamins are not easily stored in the body and the excess amounts leave the body as excess urine and waste. However fat- soluble vitamins are stored in fats, liver and tissues of the body.
There are many vitamins that can be absorbed by the body; Vitamin B and Vitamin C are vitamins that are soluble. Vitamins A, E, K and D are known as fat soluble vitamins, these fat soluble vitamins are stored in the liver and many other fat tissues within the body. Vitamins that are not dissolved easily are removed as excess through the urine.