GradGrrl

Well, since lactose is a secondary compound made of glucose and galactose, this break up occurs first via lactase, so technically lactose won't make it to the mitochondria, it will be enzymatically digested in the SI and carbohydrate metabolism will proceed in that direction.

I had a test today in Biochemstry.

 

In one of the questions the professor asked:

 

Assuming you interfere with the van-der-waals intercations between phospholipids that create a biological plasma membrane' date=' what will happen ?:

 

1) The fluidity of the membrane will go down.

2) The fluidity of the membrane will go up.

3) It will have no effect on the membrane fluidity.

 

Is there a single *definitive* answer for this question ?.[/quote']

 

That really is a horrible question.

 

First of all, if the meaning of fluidity in the plasma membrane means that hydrophobic channels allow hydrophobic residues pass, then fluidity will most certainly decrease if you interfere with van der Waals interactions, which increase hydrophobicity and are required in order for amphiphilic proteins to proceed through a channel.

 

If on the other hand, fluidity means breaking up the hydrophobic forces keeping it all together, as in actually making it more "fluid-like" then fluidity will increase.

 

If I were taking that test, I would have assumed the first meaning.

 

I hate multiple choice questions.

I just thought I would introduce myself. I am a first year PhD student studying molecular biology and i am glad to have found a place to chat!