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Physiology & Medicine
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25/07/2004 11:54:06 »
can an enzyme help in the production of another enzyme??
Are the secondary messengers like cAMP enzymes and if they are enzymes then how can we say that these are enzymes when they dont have pretein in their structures.
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Neilep Level Member
The Naked Scientist
Re: enzyme production
Reply #1 on:
30/07/2004 06:21:59 »
Absolutely - at a simple level consider the digestive enzymes in pancreatic juice. They are all secreted as inactive pro-enzymes (so that they don't digest the pancreas itself). One of these 'pro-enzymes', trypsinogen, is then cut, producing active trypsin, by an enzyme called enterokinase which is secreted by the gut wall. The now active trypsin then cuts all of the other pro-enzymes in just the right way to activate them, and digestion begins - hey presto, an example of an enzyme being used in the production of another.
The process works by cutting off a small piece of the protein in the pro-enzyme which blocks up the active site on the enzyme and stops it from working. It's rather like the protective tape over the head of your bubble-jet ink cartridge. Once you pull off the tape the head can print.
At a more complex level, when cells make proteins (which of course includ enzymes) the formation of the peptide bonds linking together each of the amino acids (the building blocks used to form proteins) are catalysed by enzymes built into the ribosomes (the structures in cells where proteins are made). And then, when the nascent protein is processed post-translationally further enzymic steps are employed to cut off pieces of the protein, add different chemical groups (e.g. sugars), and in the formation of linkages between different parts of the protein.
There are not many enzymes that are formed without help from other enzymes in the first place in fact.
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I never forget a face, but in your case I'll make an exception - Groucho Marx