Introduction
Proteins are known to be blocks that build our bodies. They are made up of amino acids. There are essential and non-essential amino acids”. Just as the word suggests, essential amino acids are required more than non-essential amino acids because they cannot be made by our bodies. However, the non-essential amino acids are made by our bodies hence they are not essential. Proteins are usually digested in the stomach by proteases. These are enzymes that are responsible for reducing proteins into smaller compounds called polypeptides.
Sources of Proteins
Proteins are derived from the food that we eat. A lot of food contains proteins. These are products from animals and plants. There are foods that contain complete sources of proteins and others contain incomplete sources of protein. Animal products like eggs and milk contain complete sources of proteins. Fish is also a complete source of protein. Plant sources are like whole grains. These are complete sources of proteins. Cereals are also considered as one of the complete sources of plant proteins. However, plant proteins lack lysine and threonine. These amino acids are only found in animal protein. Sources of plant proteins are wheat, sorghum, oats and spaghetti (Wardlaw, 2012). Legumes and some nuts are also known to contain complete sources of proteins. They have a higher percentage of proteins compared to cereals. Such legumes include soybeans, chickpeas and almonds. Nuts include walnuts and cashew nuts.
Purpose of Proteins in our Bodies
Proteins play a major role in our bodies. They help in building, repairing, regulating and protecting our bodies. The amino acids are used mostly for helping people to grow. That is why proteins are termed as blocks that build our bodies. Proteins are also used in repairing body cells and tissues. Cells and tissues mostly affected are found in muscles where there are a lot of activities. Sometimes these tissues are damaged. Proteins are therefore used to repair these damaged tissues. They are used to make enzymes that are used in the digestion of food in our bodies. These enzymes act as catalysts (Lemon, 2000). They always speed up reactions. These enzymes include pepsin, protease, etc. Hormones are also manufactured using proteins. These are used in controlling many activities of the body. For instance, hormones such as progesterone and testosterone regulate the activities of reproduction.
Proteins are also useful in the synthesis of immune cells which are important in the protection of our bodies. Immune cells fight micro-organisms that cause diseases. These immune cells are sometimes destroyed when fighting and they need to be replaced. Wardlaw (2012) noted that proteins play a big role in synthesizing and replacing damaged immune cells. Proteins are used in other body processes like contracting muscles and the transportation of nutrients. These are activities that depend on proteins to continue their activities. Proteins have another purpose of providing energy to the body. There are some proteins that are broken down to provide energy although this is not a common cause. Some proteins like collagen are useful in the growing of nails and hair. They help in making our hair and nails healthy. Proteins are very useful in molecular transport. A good example is a hemoglobin which carries iron to where it is needed. This is usually carried to various body parts of the body from the lungs.
Structural Proteins
They are known to be less active in our bodies. They are also parts of the body, i.e. fibers of the muscles. They offer strength and help in supporting parts of the body. They include ligaments. These structural proteins are part of nails and cartilages. They also form fibers of the muscles of the heart.
Effects of Protein Consumption
High consumption of proteins often leads to obesity because many proteins found in animal products have saturated fats (Lemon, 2000). These fats are always deposited on our bodies and make someone obese. They also raise the cholesterol level of the blood and this always leads to cardiac arrest. High consumption of proteins leads to a high breakdown of proteins and this leads to overworking of kidneys. There is always an excess urinary output. Too much consumption of proteins leads to more synthesis of insulin. This causes insulin resistance.
Low consumption of proteins causes hair loss. A protein called keratin is used to grow hair. When less consumption of protein is taken, this leads to hair loss because there is no excess protein for the growth of hair. Low consumption of protein also leads to weakening of the immune system which helps in the protection of our bodies. Decreased mass of the body is caused by a low intake of proteins (Wardlaw, 2012). Proteins contribute to the growth and size of the body. This is the main reason why athletes and muscle-building people consume high quantities of proteins. When low quantities of proteins are consumed, this leads to loss of body mass. This can be seen in children who suffer from protein deficiency diseases like kwashiorkor. Their legs, hands and body are emaciated. However, low consumption of proteins has one benefit of decreasing chances of getting cancer. Factors associated with risks of getting cancer are not synthesized in large quantities when one consumes less quantity of proteins.
References
Lemon, P. (2000). Beyond the Zone: Protein Needs of Active Individuals. Journal of the American College of Nutrition, 19(5), 513–521.
Wardlaw, M.G. (2012). Wardlaw’s Perspectives in Nutrition. New York: McGraw-Hill Companies.