Thread: Biology Homework!!! Phospholipid molecules!!!?

I have been given 3 questions to answer but i'm not sure how to answer them.

1. Describe how you would expect the phospholipid molecules to be arranged on the surface of the water?

2. Explain why you might expect the phospholipid molecules to cover an area approximately twice that of the total surface area

3. Explain how the reliability of the results can be assessed when investigating the effect of temperature or alcohol on the permeability of a cell membrane
Ooops forgot to add the starter so i'll write it again

In an experiment to investigate the structure of cell membranes; the phospholipid molecules from the surface membrane of a known number of red blood cells were carefully floated on the surface of water.


1. Describe how you would expect the phospholipid molecules to be arranged on the surface of the water?

2. Explain why you might expect the phospholipid molecules to cover an area approximately twice that of the total surface area

3. Explain how the reliability of the results can be assessed when investigating the effect of temperature or alcohol on the permeability of a cell membrane

i don't care about you... your nothing but a loser!!!!!!!!!! WATCHA!

1. hydrophobic tail in, hydrophylic head out
2.surface area of what?
3.haha, I guess you just get the answer to #1

ok,
phospholipids consist of two main parts, the phospholipid head, and the fatty acid tail.
the fatty acid tail is hydrophobic and the head is hydrophilic i.e. 'likes water' this means that a cell membrane exists as a double layer with the fatty acid chains on the inside and the phospho bit on the outside, hence twice what you would expect, as for q1 they would arrange themselves so that the fatty acid chains are in the middle. hope this helps- this is quite an important concept