Congo river

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

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Congo river

Post by om09404n » Fri Apr 01, 2005 12:47 am

While crossing the Limpopo River on safari in Africa, a friend of yours was bitten by a poisonous water snake and nearly died from extensive hemolysis. A true biologist at heart, he captured the snake before he passed out and has asked you to analyze the venom to discover the basis of its hemolytic activity. You find that the venom contains a protease (degrades protein), a neuraminidase (removes sialic acid from gangliosides) and a phospholipase (cleaves bonds in phospholipids). Treatment of isolated red bloood cells with each of these enzymes purified from the venom gave the resilts shown in the table below.

Analysis of the products of hemolysis produced by the phospholipase treatment showed an enormous increase in free phosphorylcholine (choline with a phosphate group attached) and diacylglycerol (glycerol with two fatty acids attached)

A) What is the substrate for the phospholipase and where is it cleaved?

B) In light of what you know of the structure of the plasma membrane, explain why the phospholipase causes lysis of the red blood cells, but the protease and neuraminidase do not?

Purified Enzyme Hemolysis

Protease NO

Neuraminidase NO

Phospholipase YES

the only thing that do know is what hemolysis means and the phospholipase anyone want to help i would appreciate it :D

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Post by mith » Fri Apr 01, 2005 2:55 am

Well it says that something was cleaved, I'm betting the original substance is composed of phosphorylcholine+diacylglycerol which is the substrate.
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Post by MrMistery » Fri Apr 01, 2005 7:24 pm

I guess mithrill is right on question A). I don't know.
About question B): the cellular membrane is composed mostly of phospholipids and only a little part of proteins. When a protein is distroyed, the lipids bind together quiclky.
IMPORTANT: the red blood cell will not be able to function properly. If all the proteins are distoryed, the blood cell will not function at all
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