Effect of Cholesterol on Cell Membrane

[maikelm]

Can someone double check if I'm thinking of this correctly?

If the temperature increases, we want to decrease fluidity (higher temperature might cause the cell to “denature” and explode because of the more kinetic energy possible) to keep the cell stable.
If the temperature drops too low (the squished cells could collapse on themselves) so we want to increase fluidity with the addition of cholesterol.

Thanks

---

Members don't see this ad.

 

[dokte]

The cholesterol doesn't make the membrane more fluid but rather rigid.
This video might help

 

[CJhooper123]

Can someone double check if I'm thinking of this correctly?

If the temperature increases, we want to decrease fluidity (higher temperature might cause the cell to “denature” and explode because of the more kinetic energy possible) to keep the cell stable.
If the temperature drops too low (the squished cells could collapse on themselves) so we want to increase fluidity with the addition of cholesterol.

Thanks

Cholesterol, to my knowledge, has the ability to both increase membrane fluidity and membrane rigidity (depending on the extracellular condition). When the cell is in a hot environment, the phospholipid bilayer has more kinetic energy and the molecules are moving around faster. Cholesterol in this case helps maintain membrane rigidity by interacting with the polar phospholipid head groups. When the cell is in a cool environment, the phospholipid bilayer has less kinetic energy and the phospholipid molecules are are moving slower and are more compact/rigid. In this case, the bulky nonpolar steroid rings "push apart" fatty acid tail packing and induce membrane fluidity.

 

[maikelm]

The cholesterol doesn't make the membrane more fluid but rather rigid.
This video might help

Thanks for the help @dokte and @CJhooper123
This video is sort of leading to what @CJhooper123 said. From what I see it, at the end, cholesterol is attempting to maintain homeostasis for the cell.

I found this (Cholesterol's Importance to the Cell Membrane):
"While cholesterol adds firmness and integrity to the plasma membrane and prevents it from becoming overly fluid, it also helps maintain its fluidity. At the high concentrations it is found in our cell's plasma membranes (close to 50 percent, molecule for molecule) cholesterol helps separate the phospholipids so that the fatty acid chains can't come together and cyrstallize. Therefore, cholesterol helps prevent extremes-- whether too fluid, or too firm-- in the consistency of the cell membrane."

You guys are both correct!