membrane structure part 2

simple diffusion

1. high to low concentration

2. movement downhill

3. passive/no energy

4. doesnt need a protein to help it through

facilitated fusion

1. transports proteins provide the pathway

2. high to low concentration

3. no energy

Active transport

1. low to high

2. movement agasint concentration

3. primary/uses energy

4. uses protein to transport

phospholipids are a barrier to what tyoe of diffusion

simple diffusion of hydrophillic solutes

4 factors impact the ability of solutes passing the layer and which ones are faster

size: smalle or large, smaller is faster

polarity: nonpolar or polar, nonpolar is faster

charged: noncharged or charged, noncharged is faster

concentration: high or low, higher is faster

what is a concentration gradient?

concentration of a solute is higher on one side of membrane than the other

this is a feature of all cells

What is electrochemical gradient

Dual gradient, occurs with solutes with a net positive or negative charge

Hypertonic solution

solute on outside is higher than inside

isotonic solution

equal distribution, solute is equal on both sides of the membrane

hypotonic

solute is higher on inside than the outside

what is osmosis

Movement of water across the membrane

molecules of a solvent tend to pass through a semipermeable membrane from a less concentrated solution into a more concentrated one.

what do plant cells use instead of osmosis

plamolysis, water will exit and the cell membrane will pull away from the cell

Channel protein

transmembrane protein that forms an open passageway for facilitated diffusion

1. closed channel, acts like a gate to come in and out when needed something also has to open the gate with signaling

transporter protein

transmembrane protein that binds on or more solutes in hydrophillic regions promoting structure changes allowing it to move from one leaflet to another

uniporter transport

they can move one thing in one direction

symporter transport

can move two things in one direction

antiporter transport

exchanges, can move two things in both directions

primary active transport involves what to transport

protein transporters

Secondary active transport involves what to transport

a pre-existing gradient which doesnt need energy

exocytosis

leaving the membrane

endocytosis

enetering the membrane

receptor meduated endocytosis

it has a receptor with a coated membrane, receptor will grab which forms a coated pit within the inside and then invagination starts to occur then whic creates a coated vesicle

phinocytosis

open invaginations take in smaller particles creating vesicles with whatever it caught

phagocytosis

for much larger things, takes in a psuedopodium and creates a vacoule called phagosome