Study Guides (248,268)
Canada (121,447)
Physiology (149)
PSL201Y1 (19)

study notes for lecture one: membrane transport

7 Pages
Unlock Document

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


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.