Bio: Topic 6 Membrane and Transport

This is for Dr. Beal's Gen Bio 115 Class at Rutgers, but open to anyone!

How does a phospholipid bilayer form?

spontaneously, due to amphipathic structure

Is phosphate polar/non polar, charged/not charged, acid/base/neutral?

polar, slightly charged, acid

Membrane Proteins determine..

how many membrane functions

Membrane proteins move…

laterally, they don’t flip

Is the tail hydrophobic or philic

phobic

Is the head hydrophobic or philic

philic

What are the membrane protein functions?

transport, enzymes, signal transduction

Polysaccharides are attached to which macromolecule?

carbohydrates

protein=

gylcoprotein

lipid=

glycolipid

cell identification is like

blood types

What is the fluid mosaic model

membrane components can move laterally within one layer of membrane

Fluid mosaic model includes

protein, lipids, and acarbs

fluidity depends on

temp, length/bend of tails, amt of cholesterol

plasma membrane is

selectively permeable

what are the two types of transport?

passive and active

describe passive

doesn’t use ATP and moves with the gradient (bike downhill)

describe active

uses ATP and moves against gradient (bike up hill) Low concentration to high

passive transport involves

diffusion, osmosis, and facilitated osmosis

does passive transport have energy

no

is atp required for passive

no

this results in

dynamic equilibrium

diffusion

tendency for molecules of a substance to fill available space.

examples for diffusion

small gases, small non polar molecules (w/ hydro carbons), small polar uncharged molecules (w/ H2O)

small gases

O2, CO2, N2

osmosis

diffusion of water across selectively permeable membrane.

water diffuses from

low to higher [solute] or higher to lower [H2O]

solvent

substance capable of dissolving other substances (Ex. water)

solute

dissolved substance (Ex. lemonade powder)

does water move towards or against higher concentration solute?

towards

osmosis toxicity

ability of a solution to cause a cell or gain or lose water

isotonic solution

equal [solute] outside cell = [solute] inside cell

NO NET H2O MOVEMENT

hypertonic

[solute] outside cell > [solute] inside cell

hypotonic

[solute] outside cell < [solute] inside cell

facilitated diffusion

large molecules or ions (H+, CA2+, NA+) transport proteins (integral proteins)

does active transport word towards or against gradient?

against

Is active transport from polar or non-polar molecules?

large polar molecules

does active transport require ATP?

yes

active transport is facilitated by…

proteins

Is passive or active transport the bulk transport of molecules?

active

Pumps/carriers

integral membrane that changes shape; requires ATP

bulk transport

large number of molecules at once

is bulk transport carrier mediated?

no

Does bulk transport pass through plasma membrane?

no

Exocytosis (out)

waste proteins and secretory products; releases contents from cell

endocytosis (in)

material taken into cell by forming vesicles derived from plasma membrane

What are the three types of Endosytosis?

1)phagocytosis

2)pinocytosis

3)receptor mediated= specific

phagocytosis

cellular eating; cell engulfs large particles; non-specific

pinocystosis

cellular drinking; ingestion of fluid and dissolved material; non-specific

receptor mediated

specific, receptor proteins in the plasma membrane bid specific molecules, form coated pits, and fold inward to form vesicles, the main mechanism for the uptake of macromolecules.