Quiz 3

Question 1

Cell membrane

Answer 1

Made up of a phospholipid bilayer

surface proteins embedded on it
integral proteins embedded into it

semi permeable - allows small uncharged molecules to diffuse in and out of cell

larger and charged molecules dont get to come in the membrane

Question 2

Phospholipid bilayer

Answer 2

polar on top
phospholipids have hydrophilic head group and a hydrophobic tail

Question 3

Cell membrane structure

Answer 3

fluid mosaic model current way describing membrane structure

fluid cuz it is in constant motion and constant activity with pieces breaking and rejoining

Question 4

Transport proteins

Answer 4

transport materials across the cell membrane

Question 5

Receptor proteins

Answer 5

Relay signals between the outside of the cell and the inside of the cell

Question 6

Enzymes

Answer 6

Catalyse specific chemical reactions occuring around cell membrane

Question 7

Cell recognition

Answer 7

some proteins act as markers that can be recognised by other cells

Question 8

simple diffusion meaning

Answer 8

Passive transport of a substance from a region of high concentration to a region with lower concentration until an equal concentration is reached

Question 9

simple diffusion eg

Answer 9

small uncharged molecules move across cell membranes by simple diffusion like oxygen and carbon dioxide

Question 10

Facilitated diffusion

Answer 10

Passive transport of a substance across a membrane through a membrane protein

Question 11

Facilitated diffusion eg

Answer 11

substance that get exchanged across the membrane by fd inclue hydrophilic molecules like glucose

Question 12

solute

Answer 12

sugar solvent causes the solute to dissolve

Question 13

Osmosis

Answer 13

Passive transport of water from a region of low solute concentration to a region of higher solute concentration across a selectively permeable membrane.

Question 14

Concentration gradient

Answer 14

The diff in concentration of dissolved substances between regions of high and low concentrations

Question 15

isotonic

Answer 15

two environmens with same solute concentrations

same concentratoin of cell - no net movement of water

Question 16

hypotonic

Answer 16

solution with lower solute concentration than the surrounding environment

lower concentration than cell - net movemnet into cell which oculd swell up and die

Question 17

hypertonic

Answer 17

solution with higher solute concentration than the surrounding environment

higher concentration than cell - waater drawn out of cell by osmosis causing the cell to shrivel

Question 18

factors that affect rate of diffusion

Answer 18

temp
concentraion gradient
surface area to volume ratio

Question 19

Active transport

Answer 19

energy requiring process of pumping molecules and ions across the membrane

requires energy from the cell in form of ATP

materials move against the concentration gradient

Question 20

Active transport Pumps

Question 21

Endocytosis

Answer 21

when a cell actively takes large molecules into itself by folding the cell membrane inward forming a vesicle

Question 22

Exocytosis

Answer 22

when a cell actively releases large molecules by fusing a vesicle with the cell membrane and releasing the contents of the vesicle to the outside of the cell