Question

There are two properties of phospholipids that affect how tightly they pack together: the length of the hydrocarbon chain and the number of double bonds. The degree of packing, in turn, influences the relative mobility of these molecules in the membrane. Which of the following would yield the most highly mobile phospholipid (listed as number of carbons and number of double bonds, respectively)?


(a) 24 carbons with 1 double bond
(b) 15 carbons with 2 double bonds
(c) 20 carbons with 2 double bonds
(d) 16 carbons with no double bonds



I thought it would be B, but I got it wrong, would someone explain it, any help is appreciated.

Thank you!

Answer 1

You're right, how did you get to that answer?

Answer 2

or was it just like a wild guess?

Answer 3

it's incorrect tho since she said she got it wrong (or he)

Answer 4

It depends on the highest number of carbons int he carbon chain and the unsaturated nature

Answer 5

unsaturated means presence of more than single bonds

Answer 6

@alphadxg
I read the chapter and I think I remember reading that the most highly motive phospholipid has to do with the number of carbons and double bonds.. As far as I know from the reading, the less the carbons and the more the double bonds, will result in an increase of the phospholipid motive.

Answer 7

I'm trying to think. Saturation does play a role, but this molecule would be in cis form so hydrogens would be on one side, and city fatty acids would be more tightly joined together.

Answer 8

@moonlight93 you're absolutely correct.

Answer 9

mobility*

Answer 10

"Which of the following would yield the most highly mobile phospholipid (listed as number of carbons and number of double bonds, respectively)?"

B? lol..

Answer 11

anything about saturation?

Answer 12

NOt B you have to have the highest number of carbons along with double bonds

Answer 13

Oh I thought 20 was B. You would assume C then.

Answer 14

so more carbon will increase mobility?

Answer 15

Lipids with shorter chains are less stiff and less viscous because they are more pron to changes in kinetic energy due to their smaller molecular size and they have less surface area to undergo stabilizing van der Waals interactions with neighboring hydrophobic chains. Lipid chains with double bonds are more fluid than lipids that are saturated with hydrogen and thus have only single bonds

Answer 16

yeah

Answer 17

Well it depends if its in the cell or elsewhere (solution),most of them are unsaturated and they form the double bonds from this (nature). this makes the be smaller in general (trans phase).

Answer 18

cool! thanks a lot Alphadxg and Rushwr, you cleared my confusion.

Answer 19

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC293596/

Answer 20

it's hard to read this but it explains it in more detail :P

Answer 21

SO basically when you have the highest number of carbons and the highest number of unsaturations the mobility is high :)

Answer 22

No problem :)

Answer 23

*Unsaturated cis fatty acids*

Answer 24

different method for quantifying cell that undergo different phases.

Answer 25

:) makes more sense now, appreciated. Both of you are best response lol

Answer 26

including Trans fats

Answer 27

FYI Viscosity is the resistance to flow. Like honey bee. It flows in a very slower manner compared to water right? That's called viscosity. In my first passage there i have included this word, was thinking if you got it or not :)

Answer 28

Thanks to both of you :)

Answer 29

No problem bubs :)

Answer 30

I know it means being thick and sticky. The DNA was viscous when when used SDS to denature its proteins in cell bio lab.