The Functions of Proteins

The Functions of Proteins

Introduction

Protein accounts for about three-fourths of the dry matter in human

tissues other than fat and bone. It is a major structural component of

hair, skin, nails, connective tissues, and body organs. It is required

for practically every essential function in the body. Proteins are

made from the following elements; carbon, hydrogen, oxygen, nitrogen

and often sulphur and phosphorus. Proteins cannot be stored except in

eggs and seeds and they form the body's main structural elements and

are found in every cell and tissue. The human body uses proteins for

growth and to build and repair bones, muscles, tissue, skin, internal

organs and blood. Hormones, antibodies and the enzymes that regulate

the body's chemical reactions are all made of protein. Without the

right proteins, blood won't clot properly and cuts won't heal and if

carbohydrates and fat can't meet your energy needs, proteins can be

broken down and used as a source of emergency energy. So this makes

protein very crucial for your health.

Each protein is a large complex molecule; these molecules are made up

of a string of amino acids. There are 20 different amino acids that

occur naturally to form proteins and they all have the same basic

structure. The 20 amino acids the body needs can be linked in

thousands of different ways to form thousands of different proteins,

each with a unique function in the body. Both the amino acids

manufactured in the liver and those derived from the breakdown of the

proteins we eat are absorbed into the blood stream and taken up by the

cells and tissues to build new proteins as needed.

The functions of ...

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...st layer of human skin, hair, and nails, and the scales,

hooves, and feathers of animals. It twists into a regularly repeating

coil called an alpha helix. Serving to protect the body against the

environment, keratin is completely insoluble in water. Its many

contains disulphide bonds which make it an extremely stable protein.

References

Website’s used:

www.Intelihealth.com,

www.dentistry.leeds.ac.uk/biochem/lectures/nutrition,

www.healthy.net/library/books/haas/funct.htm,

www.newton.dep.anl.gov/askasci/bio99/bio99395.htm,

www.bmb.leeds.ac.uk/tpdg/hglobin.htm,

Books:

Title: AS Biology, Author: Indge/Rowland/Baker, Publisher: Hodder &

Stoughton

Title: Human Biology, Author: G.D. Chalk/G.P.J. Baster, Publisher: E.

Arnold

Software’s:

Microsoft Encarta 2000 Encyclopedia Deluxe Version