Functions of Proteins

The Functions of Proteins in Living Organisms

Proteins are structured from many amino acids joined together end to end. Proteins comprise of amino acids, oxygen, carbon, hydrogen and nitrogen, some may contain sulphur.
Proteins are considered 'the building blocks' of all living organisms and are found in all cells in the human body. Proteins help with many functions in organisms including transporting oxygen, replicating DNA and fighting illness. Proteins hold great importance to life as they help regulate every function in the body such as building bones and muscle, which in the young is vital for growth and development.
Keratin is the chief structural constituent in making up the outer layer of skin, hair and nails in humans whilst making up fur, feathers, scales and horns in other animals. Keratin is a fibrous protein that forms long chains that run parallel to one another. These chains are linked by cross bridges thus forming very strong, stable molecules. These molecules consists of tight coiled polypeptide chains that combine together to form supercoils. Keratin is formed by keratinocytes; these are living cells found in skin cells. These keratinocytes move up through the layers of skin as they age. When they die they form a protective barrier found in the epidermis to protect against bacteria and outside elements. This process can be caused to accelerate by certain medical conditions such as psoriasis.
Keratin controls cell growth and renewal. There are two types of keratin, alpha-keratin that is found in humans and mammals and beta-keratin which is found primarily in birds and reptiles (Bio-Medicine.org). Keratin is a major component in hair and fur making it less likely to break and damage, coating the strands to keep in moisture. This fibrous protein is found in the outer epidermis and helps maintain skins elasticity and firmness. It also has an influence on melanin and skin pigmentation. For nails and other hardened structures keratin plays a...