destroyer bio #303

[mistero]

---

Members do not see this ad.

I am a little confused with this one. I hope I explain my question well.

the question gives a few bands on a SDS polyacrylamide gel and asks which one corresponds to the protein lysozyme. Thye lysozyme is the one on the bottom, near the positive end.

Possible MW's are given.

The answer in destroyer is the smallest MW. I don't understand, I thought when it has a smaller MW, it moves faster and will be the furthest band.

Please help. Thanks.

 

[HowAboutDAT]

If im not mistaken, all of the proteins are first placed at the negative end of the gel, and then a charge is run through it. The proteins are then separated based on charge and their size. The proteins with the lowest molecular weights move fastest and travel the farthest. Thus, E, the lysozyme would have to have the lowest MW.

 

[Mamona]

If im not mistaken, all of the proteins are first placed at the negative end of the gel, and then a charge is run through it. The proteins are then separated based on charge and their size. The proteins with the lowest molecular weights move fastest and travel the farthest. Thus, E, the lysozyme would have to have the lowest MW.

You are correct!!!! Maybe you should look at the difference between SDS and gel filtration chromatography (aka ion exchange chromatography) in this type of technique usually the big molecules elute first, but also it deals with polarity of the molecule and the type of gel use.