Biological Membranes

What do oligosaccharides help with?

Cell recognition

What keeps things fluid?

Cholesterol

How does simple diffusion flow?

Down the concentration gradient, high to low

Does simple diffusion use ATP?

No

What can pass during simple diffusion?

small, uncharged hydrophobic molecules and gases and water

What happens to the rate of diffusion with temperature?

Higher temp, higher rate of diffusion

What happens to rate of diffusion with surface area?

larger surface area, higher rate of diffusion

What happens to the rate of diffusion with molecular size?

larger molecules, lower rate of diffusion 

What happens to the rate of diffusion with pressure?

steeper pressure gradients, higher rate of diffusion

What happens to the rate of diffusion with distance?

faster over short, slower over fast

How does movement happen during facilitated diffusion?

Down the concentration gradient

What helps aid movement during facilitated diffusion?

Proteins

Pore-forming transmembrane proteins

Channel proteins

Open and close in response to specific signals

Gated

What are some describers of channel proteins?

Gated, selective, and rapid response

Change shape during transport

Carrier proteins

What are some describers of carrier proteins?

Selective, slower response, and can only carry one molecule at a time

Water moves down its concentration gradient, no ATP needed

Osmosis

What allows water to move during osmosis?

Selectively permeable membrane

Lower concentration of water

Hypertonic

Higher concentration of water

Hypotonic

How does water move in concentrations?

Hypotonic to hypertonic

Same concentration of water

Isotonic

What happens if a cell is in a hypotonic solution?

there is more water in and less water out

What happens if a cell is in a hypertonic solution?

there is more water out and less water in

Water channels that facilitate rapid water movement

Aquaporins

How does water move in active transport?

Against the concentration gradient

Is energy investment required in active transport?

Yes

Movement of substances into and out of cells by vesicles

Vesicular transport

Membrane bound sac

Vesicle

Substance released from cell

Exocytosis

Substance brought into cell

Endocytosis

Bring in chunks needed for nutrients

Phagocytosis

Bringing in what happens to be around it, keeps what it wants, gets rid of rest

Pinocytosis

Brings in many different things, highly-selective

Receptor-mediated endocytosis

Membrane protein with binding site that is specific shape for signal to bind

Receptor

Which is more fluid? Unsaturated or saturated fatty acids?

Unsaturated

Are longer or shorter tails more fluid?

Short

Are high temps or low temps more fluid?

Low

What affect does protein have on fluidity?

More proteins, less fluid

Enzyme that inserts double bond into fatty acid

Desaturate