Sources of protein


Proteins are nutrients that make up the tissues of our body like muscles or bones. Proteins help us grow and healthy. Proteins helps in repairing cell and tissues and it is the main component which is important for our skin, hair, bones and nails. Proteins are essential part of human diet. Proteins are found in variety of foods like eggs, dairy products, sea food, meat, nuts and seeds. These proteins are broken down into refold smaller chain. Chain of amino acid is bound to one another by peptide bond. Dietary proteins provide essential amino acids that are needed to make a protein, hormones and other important molecule. We need to break dietary protein down first by the process called proteolysis. When dietary protein enters the stomach first HCL denatures the protein and unfolding making the amino acid chain more accessible to the enzymatic reaction then PEPSIN which is protein itself made by gastric chief cells, PEPSIN cleaves the protein into the oligopeptide chain which move into the duodenum where the digestive enzyme made by pancreas further breakdown the oligopeptides into tripeptides and dipeptides and individual amino acid. These now is taken up by intestinal cell which di and tri peptides is converted into further amino acids. Some amino acids in the intestinal cell are used to synthesize intestinal enzymes and new cells but most enter the bloodstream and transported into other parts. Proteins may be either complete or incomplete. Complete proteins are those proteins in which all essential amino acids are present on the other hand incomplete proteins are those proteins in which all essential amino acids are not present but provides some like beans, nuts and grains. Protein needs vary depending on lifecycle stage and health status. Protein is classified based on function, chemical composition, structure/shape and nutritional value. Basic protein requirements are 0.8g/kg of the body. The main source, of Proteins are animals because all essential amino acids are present in meat, of animals we get protein from the meat of fish, chicken etc. The second source is the plant for example pulses, beans, grains of maize and peanut although proteins present in plant in less amount, eating food high in protein offers a range of health benefits. Animal source is EGG which is one of the healthiest foods on the planet it contains almost every nutrient needed by the body. Egg contains 6g (per 100g). Also Chicken breast is the great source of proteins strengthening bones and building muscles has never been so easy. Chicken breast contain31g (per 100g). Beef is there Out of 10 essential amino acids beef contains 8 essential amino acids. 26g (per 100g). Fish is a good source of protein it contains 21-25g per 100g protein and 8-12g fat, but it, is good fat and within the heart health it is beneficial for skin, eyes, hair and nails. Vegetables which contain high proteins are Spinach, peas, chickpeas, potatoes, broccoli, corn, artichokes, lentils, soybeans while as fruits which are rich in protein are Pomegranate (5g per 100g), Guava (2.6g per 100g), Dates (2.4g per 100g), Avocado (2g per 100g) and Dry apricot (1.4g per 100g).

(-The writer is student of Master of Science (Biochemistry) in the University of Karachi.)