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The Role of Proteins

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ROLE OF PROTEINS Proteins have several different functions in both plants and animals. Proteins are made up of many amino acid molecules all bonded together by peptide bonds. Therefore proteins are also known as polypeptides. Protein synthesis occurs on the ribosomes of cells and require a supply of amino acids which is found in the cytoplasm. Amino acids constitute of carbon, hydrogen, oxygen and nitrogen atoms and sometimes may include sulphates and phosphates. As shown below a typical amino acid has an amino group on one end and a carboxyl group on the other end. Also any other type of group ((r)) ...read more.


The buffering effect may take place, for example, in the stomach. So when the conditions are too acidic then the amino group can take in the excess hydrogen ions or if the pH is too high then the carboxyl group can release extra hydrogen ions. There are different structures of proteins depending on the (r) group present in the amino acids. The primary structure is a linear sequence of amino acids. The secondary structure is a repeated pattern of amino acids eg. helixes or pleats. The tertiary structure is a 3D folding of the secondary structure and the quaternary structure is many different complex polypeptide chains linking together. ...read more.


Some of these proteins include keratin and collagen which provide structure in skin, hair, nails, connective tissue and blood vessels. Globular proteins form complex tertiary and quaternary structures such as those functioning as contraction, enzyme, hormone, homeostatic, protective and transportive proteins. Contraction proteins are actin and myosin and are found in the muscle tissue. Enzymes such as amylase increase the rate of metablic reactions. Hormones, such as insulin found in the blood and produced in the islets of langerhams in the pancreas, are globular proteins that are chemical messengers. Protective proteins include antibodies produced by lymphocytes and fibrinogen present in the blood and lastly transportative proteins include haemoglobin in all vertebrates. ?? ?? ?? ?? Milan Shah - 12E ...read more.

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