Question

What happens to the cell membrane of the polar bear if it is placed in the desert

Answer 1

Die of starvation/dehydration/the heat.
The heat will probably kill it first.

Well im just speculating but from what i know Polar bears has a vast lipidlayer underneath the skin which protects them from the cold. If you put that in a very hot climate the body temperature will rise exponatially, and to far above homoestas temperature can cause cells to go into necrosis. Vital organs would stop to function.

Reviewing that, you would only have to see the process of necrosis to have your answer.

"Necrosis typically begins with cell swelling, chromatin digestion, and disruption of the plasma membrane and organelle membranes. Late necrosis is characterized by extensive DNA hydrolysis, vacuolation of the endoplasmic reticulum, organelle breakdown, and cell lysis. The release of intracellular content after plasma membrane rupture is the cause of inflammation in necrosis."
Source: http://en.wikipedia.org/wiki/Necrosis

Answer 2

but to talk about only the cell membrane, since there is chloesterol, lipoprotein, and others..
what i want to know is, will they get denature ?

Answer 3

and also the phospholipid, will they break when heated?then the cell membrane will be permeable to everything and lose equilibrium

Answer 4

I would assume Lipoproteins would denaturate, i would have to research this question further to give you a proper answer though. I'll review my books.

Answer 5

okay!! i will wait :D
did u just join openstudy? never see u before!

Answer 6

Yes i joined two days ago.

I found this phrase in a study on cryogenically freezing humans, nonetheless i believe it applies both ways, keep in mind this study was conducted quite a while ago.

"Lipid-protein complexes are held together not by the relatively strong covalent bonds which link the atoms of simple protein, but by weak association force similar to those supporting a soap bubble. Because of the tenous natur of the forces binding their components, these complexes are inherently unstable and probably maintained in living cells by continous synthesis"
Source: http://www.jstor.org/pss/83158

Answer 7

yes,if the lipoprotein doesnt function, is it that the cell cannot recognize what is going in

Answer 8

mostly fats, like toxins and stuff

Answer 9

I reviewed my books and came up empty, from what i've could gather on the internet that makes any sense would be that.

From what i know of necrosis is that no toxins are released into the enviroment untill the cell membrane bursts, the best way i could explain it would be like blowing up a ballon.
To get back to the point of what happends to the cell membrane, my hypothesis would be the following:
Temperature rises -> Phospholipids becomes more permiable which not only disrupts the electrolyte balance of the cell among other things, but also creates a bigger strain on the Cholesterol which creates the mechanical stability behind cell membrane, The protein chain in Lipoprotein goes through denaturatation (from what i could gathered lipid chains can denaturate.) -> untill ultimately the cell erupts from the diffusional build up in the intracellular cytosol.


"At physiological, or body temperature, the cells function their best. As temperatures increase, both the cell membrane and the proteins can be affected. The fatty acid tails of the phospholipid bilayer can "melt" at high temperatures meaning that they become more fluid and allow more movement. This affects the permeability of the cell which may allow molecules into the cells that should not get in, thereby damaging the cell.
The transmembrane or peripheral proteins can also be damaged by high temperatures. High temperatures cause proteins to denature, or break down. Increased temperatures also increase the reactions that happen within the cells, which may be acceptable to a point, until the temperature becomes too high which will destroy the protein, the reactions and the cells."

Read more: The Effect of Temperature on Cell Membranes | eHow.com http://www.ehow.com/about_5516866_effect-temperature-cell-membranes.html#ixzz1ntn5uH7e

Answer 10

*Clarification
1) Im assuming Polar bears necrosis process is identical to that of humans of course.
2) Im considering this from Necrotic cell Zero. otherwise the paracrin cells could just aswell die from the released Lysozomes of the paracrin necrotic cell.

Answer 11

yea ty :D come to openstudy often so we can discuss more :D!!! I really like discussions!