Unit 2 - Membrane & Transport

What kind of particles can pass through hydrophobic fatty acid tails at center of bilayer?

hydrophobic (uncharged) & small particles

Two examples of simple diffusion…

oxygen & carbon dioxide

Define osmosis

passive transport of water from low solute to high solute concentration through a semipermeable membrane

Define facilitated diffusion

passive transport of molecules from a region of high to low concentration through channel proteins

Define active transport

movement of particles from region of low to high concentration using protein pumps and ATP energy; (against concentration gradient)

Compared to simple diffusion, facilitated diffusion and active transport are __________.

selective!

Name 4 functions of glycoproteins and glycolipids (think RICC)

1. Receptors

2. Immune Response (antigens)

3. Cell to Cell Communication

4. Cell to Cell Adhesion

Saturated fatty acids have ______ melting points. Think like butter!

higher

Unsaturated Fatty Acids have ________ melting points. Think bent, so weird alignment, easier to break! (oil)

lower

How does cholesterol regulate membrane fluidity?

stabilizes at high temperatures & prevents stiffening at low temperatures (literally exactly what you would want it to do!)

Name an example of exocytosis and endocytosis (in that order)

proteins; bacteria or antibodies

Define voltage gated channel and give an example.

1. responds to changes in membrane potential difference

2. ex. sodium & potassium voltage gated channels

Define ligand (neurotransmitter) gated ion channels and give an example.

1. responds to ligand attaching to a channel

2. ex. Acetylcholine receptors

Lets simply sodium potassium pumps. What goes in and out, and how much?

3 Na out, 2 K in

Are sodium potassium pumps active or passive transport and why?

active; transports both against concentration gradients

YO explain what the heck sodium dependent glucose cotransporters do!

enables glucose to move against concentration gradient by linking it with Na+ ions which will move up its gradient

the transport of glucose DEPENDS on the active transport of Na+ out of epithelial cells

What is a CAM?!

Cell-adhesion molecules (used in diff. cell junctions)

Attraction between H20 molecules and ions help ________ a solution

disperse

What happens to cells in a isotonic solution? What do we call it!?

no net movement of water (dynamic equilibrium!)

What is it called when animal cells are placed in hypertonic solution and shrinkkkkk

crenation

What is it called when animal cells are placed in hypotonic solution and burstttt

cytolysis

What do contractile vacuoles do?

Help with osmoregulation by taking in excess water in hypotonic environments; prevents cytolysis