Study Guides (238,095)
Canada (114,916)
Physiology (145)
PSL201Y1 (19)

study notes for lecture one: membrane transport

7 Pages
Unlock Document

University of Toronto St. George
Doug Mac Kay

LECTURE ONE: MEMBRANE TRANSPORT SPOTLIGHT ON:CELL MEMBRANE Composition Transport Mechanism Fluidity Permeability - phospholipid bilayer if a substance can cross the membrane by any means = the membrane is o determined by lipid - fluid mosaic model permeable to that substance composition - glycocalyx gases and lipid-soluble molecules diffuse through readily across the o fluidity is essential for - proteins for structural membrane efficient carrier and channel supportanchors for cytoskeleton impermeable to organic anions (like proteins) protein function {the framework inside the cell} polar molecules and ions need the help of proteins channels or carriers o cholesterol is inserted - transmembrane protein channels to cross among FA chains to - protein transporterscarriers water diffuse via aquaporin channels stabilize the membrane and - receptors TM channels for diffusion of selected moleculesions prevent diffusion of polar - enzymesion pumps selective transporterscarriers for transport across membrane for molecules across it - cholesterol molecules o reduced by aging and poor receptors for signalling molecules diet enzymesion pumps for active transport MEMBRANE PROTEINS TYPE Structure & Composition Function Other Considerations phospholipid - polar head group (phosphate group determines fluidity of membrane o head group may be neutral or and head group) saturated tails are straight-chain alkanes negatively charged - glycerol backbone and pack very tightly resulting in rigid o phosphate group always carries a - hydrophobic tails structures negative charge - polar end = glycerol + phosphate unsaturated tails contain alkenesdouble o hydrophobic tails can be (hydrophilic) + serinecholineetc bonds which create kinks, allowing saturated (all single bonds) or {head group} fluidity, disrupt tight packing unsaturated (double bonds) - non-polar end = 2 long FA chains tails associate with proteins o normally one FA is saturated and (hydrophobic) unsaturation of hydrophobic tails regulates the other is polyunsaturated melting temperature by lowering it as it o amphi-philicphatic molecules = takes less energy to break the bonds that have both highly polar and are not packed tightly highly non-polar regions o 1
More Less

Related notes for PSL201Y1

Log In


Don't have an account?

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.