Class Notes (835,600)
Canada (509,275)
Biochemistry (187)
BIOCH200 (135)

BIOCH 200 (March 14, 2014) - Biological Membranes

2 Pages
Unlock Document

Walter Dixon

BIOCH 200 – Biological Membranes (con’t)  (March 14, 2014) • *Cholesterol helps maintain BOTH fluidity and stability of the lipid bilayer o *Help maintain rigidity: by reducing rotational capabilities of the acyl tails at high temperatures o *Help maintain fluidity: by preventing close chain-packing between acyl chains in cold temperatures • *Transition temperature – temperature at which the lipid membrane turns from a crystalline state to a more fluid state o *Remember, the lipids are held together by hydrophobic interactions… NOT covalent bonding o *Is usually a range o If a cell is exposed to colder temperatures, it’s membrane will have a higher unsaturated lipid content, to counteract crystallizing temperatures (cell synthesizes them in response) o If a cell is exposed to higher temperatures, the cell will synthesize a higher amount of saturated lipids for the lipid membrane to maintain stability. o Membranes must exist ABOVE gel temperature  *At gel temperature, lipid bilayer is too stiff to allow for molecules to pass through efficiently  cell doesn’t get nutrients fast enough  cell dies • Lipids of membrane: o Travel laterally o *Do some transverse diffusion (flip-flopping to other side of membrane) but rarely  Process is catalyzed by flippase enzym
More Less

Related notes for BIOCH200

Log In


Join OneClass

Access over 10 million pages of study
documents for 1.3 million courses.

Sign up

Join to view


By registering, I agree to the Terms and Privacy Policies
Already have an account?
Just a few more details

So we can recommend you notes for your school.

Reset Password

Please enter below the email address you registered with and we will send you a link to reset your password.

Add your courses

Get notes from the top students in your class.