Fuction of proteins

[nick3188]

Can anyone tell me about the fuction of specific proteins and how, their specific shape allows this?

[j2buttonsw]

I'll get the ball rolling: proteins can be structural (like muscle) or functional (like enzymes). They are made up of chains of amino acids with the primary structure being the order of amino acids in the chain. There is a secondary structure which is how the chain of AAs are folded or coiled (as, for example, alpha helices or beta pleats). Then there is a tertiary structure which is how the secondary structure is further folded. In addition there is a quaternary structure which is how the constituents of a multi-component proteins are held together. Structural proteins like collagen are comprised of tightly coilled alpha helices to give it strength whereas the tertiary and quaternary structure of enzymes define their shape and how they react with the substrate and the positioning of active groups involved in the chemical reaction they catalyses.