FoB Lecture 4

What is the main difference between lipids and fatty acids?

lipids: non polar (hydrogen and carbon), hydrophobic

fatty acid: AMPHIPATHIC (polar and nonpolar regions)

what are 5 types of lipids?

saturated fatty acids, unsaturated fatty acids, phospholipids, triglyceride

what is the difference between saturated and non saturated?

saturated: single bonds

unsaturated: single and double bonds (can be cis or trans)

What are the better fatty acids? (transfat/unsaturated)

transfat: bad

unsaturated w CIS bonds: causes kinks in chains

What do butter, oil and honey fall under for unsaturated/saturated/chian length?

saturated short chain: butter

saturated long-ish chain: wax

unsaturated - short chain: oil

What word describes the lipid bilayer?

amphipathic molecules that spontaneously (naturally) arrange because of how different regions of phospholipids interact with water (make up membranes of all cells)

What are the differences in saturation/stability between saturated and unsaturated?

unsaturated: more fluid

saturated: more viscous

what does cholesterol do for the membrane?

keeps the lipid bilaey more stable at high temperatures and more fluid at low temperatures

what type and size of particle can pass through the bilayer?

small and nonpolar molecules (O2, CO2, steriod hormone)

what particles cannot pass through the bilayer?

“large and in charge” particles/proteins - need a channel/carrier protein

ex: Cl-, PO3-4

what is the difference between active or passive transport?

active: uses energy (ATP) to move molecules AGAINST (low to high) their concentration gradient (uses a protein)

passive: does not use energy and moves molecules down their concentration gradient

what are channel proteins and carrier proteins?

specialized tunnels that work to assist large polar molecules and ions across the bilayer; specialized

channel proteins: passive - think of a tube

carrier: changes shape (passive/active)

what is facilitated diffusion? what molecules use this?

passive transport across a cell membrane WITHOUT energy going down the gradient

small nonpolar

what is osmosis?

water movement in the direction of MORE SALTY/SOLUTE (water will travel to high solute concentration to help dilute it)