agarose gel

[mslynnlynn]

i want to know the answer of these questions. please, help me.
1.differences between polyacrylamide and agarose gel.
2.the most useful method of protein sequencing.
3.difference bet: the structure of heme and of chlorophyll
4.which enzyme is used in PCR amplification?

[zami'87.]

4.Taq polymerase-thermostable DNA polymerase
1. Hmmm It's less complicated to make agarose gel but polyacrilamide gel has higher resolution(can separate DNA fragments with little difference in length).

[MrMistery]

3. You have to be joking!!! Chlorophil is an extremely big organic molecule. But here is a little glimps on the misteries of the chlorophil molecule:
It's base unit is a tetrapirolic ring. This is converted later into something called protoporfirin(not sure if that is the corect english translation though). Protoporfirin can go 2 separate ways: you insert iron in it and you get heme or you inser magnezium and you get chlorophil.
Now i do not know the structure of heme but here is something about the structure of chlorophil. There are 5 types(a,b,c,d,e) but as only a and b are found in plants i am going to talk about them. Chlorophil a has the chemical formula C55H72O5N4Mg and a molecular weight of 893,4. Chlorophil b has the chemical formula C55H70O6N4Mg and a molecular weight of ... sorry i can't remember The difference between them is chlorophil a has a methilin group(CH3) where chlorphil b has an aldehidic group(CHO)

Hope this helps. Take notice, if you want to truly answer this question you will have to make a really intense study

[Poison]

A very 'simple' explanation, Andrew...

[MrMistery]

It was simple. In my photosynthesis book it has 5 pages on the molecular structure and chemical properties of chlorophil. However, what i said is enough for grade school

[Jelanen]

RE question 1:

Agarose gel is a naturally occuring substance derived from seaweed. It sets up into something like jell-o with a little firmer consistancy. It has big holes so its really only useful for separating out big molecules like DNA. Polyacrylamide gel is synthetic and can be made in varying pore sizes so you can filter many different things just by varying the initial chemical proportions when you mix it up. Also, PA gel can be made in layers so you can have step changes in pore sizes since PA gel set is a chemical reaction as opposed to agarose gel's cooling.

-Jelanen

[Anne]

Re: question 2: Possibly the Edman degradation method

[Daniel Tillett]

2. Mass spec is easier if you know the genome from which the protein came.

[eTiT]

(1) differences between polyacrylamide and agarose gel.

Polyacrylamide is SDS-PAGE used to seperate proteins and is an example of discontinuous electrophoresis( with 2 gels-- stacking and revolving gel). Agarose gel is used to separate fragments of DNA, an example of continuous electrophoresis.