USES OF PROTEINS FOR FOOD
Proteins are an important component of our food. Proteins build up, maintain and replace the tissues in our body. Our muscles, our organs, and our immune systems are made up mostly of protein. Our body uses the protein we eat to make large number of specialized protein molecules that have specific functions.
The best sources of proteins are poultry, fish, eggs, nuts, dairy products, (such as milk, cheese, curd) seeds and legumes.
Proteins, in our food, supply the essential amino acids which our body is unable to synthesize. When we eat food that contains proteins, the digestive juices in the stomach and intestines break down the proteins present in food into amino acids. The amino acids then can be used to give energy that our body needs to perform various functions.
FUNCTIONS OF PROTEINS
Some of the different forms of proteins and their important functions in human body are given below:
- Proteins are needed for growth and repair of the body growing children need proteins in large quantities for making new tissues. Proteins as muscle, skin, hair and other tissues constitute the bulk of body’s non-skeletal structure.
- Some proteins as hormones regulate many body functions. For example, the hormone insulin is a protein. It regulates sugar level in the blood.
- Some proteins as enzymes catalyse or help in biochemical reactions. For example, pepsin and trypsin.
- Some proteins act as antibodies, and protect the body from the effect of invading species or substances.
- Transport proteins carry different substances in the blood to different tissues. For example, haemoglobin is a transport protein. It carries oxygen from lungs to the tissues and carbon dioxide from tissues to the lungs.
- Contractile proteins help in contraction of muscle and other cells of our body. Myosin is an example of contractile protein.
- Proteins also serve as a source of energy when the carbohydrates are not available in the food, especially during long fasting or starvation.
- Proteins act as buffers and maintain appropriate pH required for many biochemical reactions.