Biological Membranes

Question 1

Osmotic Pressure

Answer 1

Colligative Property
It is the pressure applied to a pure solvent to prevent osmosis and is related to the concentration of the solution

II= iMRT

Question 2

Passive Transport

Answer 2

does not require ATP because the molecule is moving down its concentration gradient or from an area of higher concentration to an area of lower concentration

Question 3

Simple Diffusion

Answer 3

does not require a transporter
small nonpolar molecules passively more from an area of high concentration to an area of low concentration until equilibrium is achieved

Question 4

Osmosis

Answer 4

describes the diffusion of water across a selectively permeable membrane

Question 5

Facilitated Diffusion

Answer 5

uses transport proteins to move impermeable solutes across the cell membrane

Question 6

Active Transport

Answer 6

requires energy in the form of ATP (primary) or an existing favourable ion gradient (secondary)
secondary can by symport or antiport

Question 7

Endocytosis and Exocytosis

Answer 7

methods of engulfing material into cells or releasing material to the exterior of cells, both via the cell membrane

Question 8

Pinocytosis

Answer 8

Ingestion of liquid into the cell from vesicles formed from the cell membrane

Question 9

Phagocytosis

Answer 9

is the ingestion of solid material

Question 10

Flipases

Answer 10

asses in moving lipids through the membrane

Question 11

Transmembrane Proteins

Answer 11

pass all the way through the lipid bilayer

Question 12

embedded proteins

Answer 12

either on just the interior or just the exterior of the cekk membrane

Question 13

Membrane association proteins

Answer 13

aka: peripheral proteins

may by bound through electrostatic interactions with the bilayer

Question 14

Cell-Cell Junctions

Answer 14

provide direct pathways of communication between neighbouring cells or cells and extracellular matrix

Question 15

Gap Junctions

Answer 15

allow direct cell to cell communication and are often found in small groups, permit movement of water and some solutes

Question 16

Tight Junctions

Answer 16

prevents solutes from leaking into the space between cells, can limit permeability and allow direct transfer of materials

Question 17

Desmosomes

Answer 17

bind adjacent cells by anchoring to their cytoskeletons, formed by interactions between transmembrane proteins associated with intermediate filaments inside adjacent cells

Question 18

Facilitated Diffusion

Answer 18

integral membrane proteins serve as tansporters, they are only open to one side of the cell and binding changes conformation of the protein to open to the other side

Question 19

Active Transport

Answer 19

moves a solute against its concentration gradient and required energy

Question 20

Primary Active Transport

Answer 20

uses ATP of another energy molecule to directly power the transport across the membrane

Question 21

Secondary Active Transport

Answer 21

harvests the energy released by a particle going down the gradient to drive a different particle up its gradient

Question 22

Endocytosis

Answer 22

cell membrane engulfs material to bring it into the cell

Question 23

Pinocytosis

Answer 23

endocytosis of fluids and dissolved particles

Question 24

Phagocytosis

Answer 24

endocytosis of large solids

Question 25

Exocytosis

Answer 25

secretory vesicles fuse with the membrane and release materials into the extracellular environment

Question 26

Sodium and Potassium Pump

Answer 26

low [Na+] and hight [K+] intracellularly by pumping 3 Na out for every 2 K in