Proteins are essential building blocks c the human body and of all living organisms. They fulfil a wide variety c functions with using merely 20 different amino acids. Antitjodies defend the body from foreign molecules or pathogens; sma proteins suchas Insulin are the means of communication between the cell; pumps transport molecules from and into cells; molecules such as collagen provide structure; proteins also act as storage for ions such as ferritin; and finally enzymes catalyse the transformation of small molecules during the catabolism of food molecules and the anabolism of complex molecules.
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