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Enzymes

Discussion of all aspects of biological molecules, biochemical processes and laboratory procedures in the field.

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Re: Enzymes

Postby Muska » Thu Feb 25, 2010 5:42 pm

So amylase breaks polysaccharides into disaccharides in the mouth. This disaccharide (in the form of maltose) travles through to the small intestine where maltese breaks the disaccharide into monosaccharide (glucose)?

Do you know how disaccharides reach the small intestine? I assume it isn't through the alimantary canal?(though I could be wrong!)
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Postby JackBean » Thu Feb 25, 2010 7:20 pm

1) proteins are (poly)peptides, you can't say it vice versa.

Muska (BTW where did you get your nick?:)
all the main components of our food are polycondensates. That means, that they are made of smaller units (amino acids in proteins; monosaccharides in carbs; fatty acids and glycerol in lipids; nucleobases and sugar-phosphate backbone in NA), which are connected by bond, made by release of water. So, when you want to break these big molecule, you add water to the previously mentioned bond and this does hydrolase in general. It hydrolyses any bond. Amylase hydrolyse glycosidic bond in carbs, pepsin hydrolyses peptide bond in polypeptides.

Look to the wiki page for Amylose
http://en.wikipedia.org/wiki/Amylase#Classification
here you can see, that there are several kinds of them differing in substrate specificity. Alpha breaks the chain in middle releasing oligosaccharides (having several Glc monomers connected), Beta cuts it from the end thus producing Glc
http://www.biolib.cz/en/main/

Cis or trans? That's what matters.
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Re: Enzymes

Postby Muska » Thu Feb 25, 2010 7:50 pm

Ahh polypeptides that does actually sort of answer another question I had- are polypeptides broken down into peptides? And then into amino acids? Or are polypeptides and peptides in reality the same thing? Are there 'dipeptides'? Or have I just made that word up?

I'm going to be honest, much of that wiki link is lost on me. I understand the very basics of enzyme breakdowns, but when you start going into 'Glc' and the such I get lost. I'm not really a biology student, I'm just taking a sort of biology for beginners module at uni to better understand the biological side of my psychology degree! fortunately I'm not quite as inept when it comes to psychology...!

Ha my name comes from a skateboarder named Chad Muska. When I was younger I used to skate and had Chad Muska's siganture deck, so a few people started calling me Muska and it kind of stuck ever since.
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Postby JackBean » Thu Feb 25, 2010 8:15 pm

No, dipeptides exist, as well as tripeptides, tetrapeptides etc.

All these molecules (saccharides, peptides, nucleotides), you can divide to mono-; oligo- and poly-
Mono is clear, that's only one
Oligo are "few", usually 2-10
Poly are many
Usually, there is little difference between polypeptides and proteins, that proteins are bigger (I think from 10 kDa?), but that can vary...

So, polyPEPTIDES are peptides, composed of many amino acids and they are broken down to smaller poly or oligopeptides (or single amino acids can be cleaved off from the terminus)
http://www.biolib.cz/en/main/

Cis or trans? That's what matters.
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Re: Enzymes

Postby Muska » Thu Feb 25, 2010 9:19 pm

Ok I now understand what you all have been trying to explain to me for the last 2 days. (By understand I mean understand on a very basic level!) But I have managed to put it into my powerpoint presentation- huzzah! And better, I know what enzymes are for and what saccharides etc are so hopefully I won't get caught out by the tutor! (A week ago I had never even heard of an enzyme, nevermind polypeptides and disaccharides etc!)

Honest to God if I hadn't have come here I would still be buried neck deep in biology books trying to get my head around the whole concept (although if I had really thought about it- the clues are in the names poly/di/mono etc.) so I owe everyone who has offered me advice here massively. I really do.

Kudos for keeping patient with me as I fumbled my way around molecular biology 101 though, really is much appreciated.
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