Cell membrane transport

Question 1

what are the 5 types of transport through the cell membrane

Answer 1

diffusion
osmosis
active transport
exocytosis
endocytosis

Question 2

features of channel protein

Answer 2

spans cell membrane
specific protein to each molecule
gated channel proteins can be open or closed depending on signal (hormone)

Question 3

features of carrier proteins

Answer 3

substance to be transported binds to specific site on protein
ATP changes shape of carrier protein and molecule crosses membrane

Question 4

when cant molecules pass through cell membrane by diffusion

Answer 4

have a strong positive or negative charge
too large
moving against concentration gradient

Question 5

what methods of transport are used for bigger molecules

Answer 5

facilitated diffusion
active transport
exocytosis
endocytosis

Question 6

define diffusion

Answer 6

net movement of molecules from a region of high concentration to a region of low concentration down a concentration gradient. reach an equilibrium.

Question 7

how to increase rate of diffusion

Answer 7

steeper concentration gradient
higher temperature (increases KE of molecules)
large surface area of membrane
smaller/ lighter molecule
thickness of membrane (thinner)

Question 8

what is simple diffusion

Answer 8

molecules smaller than CO2 can diffuse across membrane
small, lipid soluble, non polar or hydrophobic molecules can diffuse simply

Question 9

is diffusion active or passive and why

Answer 9

passive
does not require energy
moves down a concentration gradient

Question 10

what is facilitated diffusion

Answer 10

when molecules are too big so require a passage created via proteins (channel / carrier proteins) in membrane
passive
down concentration gradient
movement of polar / larger molecule (than CO2)

Question 11

define osmosis

Answer 11

net movement of water molecules from a solution of lower concentration solutes (higher concentration of free water molecules) — solution of higher concentration of solutes (lower concentration of free water molecules).
through a partially permeable membrane
down a concentration gradient
passive

Question 12

features of active transport

Answer 12

movement of molecule across a membrane against a concentration gradient
active
uses ATP to drive protein pumps in membrane

Question 13

what do carrier proteins do in active transport and what do they need to function

Answer 13

act as pumps
complementary shape to molecule so are specific to individual molecules
require ATP
move molecules faster than diffusion

Question 14

how does active transport work

Answer 14

channel or carrier proteins involved
ATP needed for transport binds and is broken down and releases energy
shape of active transport protein changes and molecule travels through membrane
active transport protein flips

Question 15

what is bulk transport

Answer 15

when cells need to move more than one molecule across membrane at a time

Question 16

what are the two types of bulk transport

Answer 16

exocytosis
endocytosis

Question 17

what is exocytosis

Answer 17

movement of molecules transported out of the cell

Question 18

what is a vesicle

Answer 18

small membrane bound sac

Question 19

process of exocytosis

Answer 19

molecule enclosed in vesicle
vesicle fuses with cell membrane (due to fluid nature of membrane)
releases contents inside outside of cell

Question 20

what is endocytosis

Answer 20

movement of particles transported into the cell

Question 21

what the process of endocytosis

Answer 21

opposite of exocytosis.
cell membrane bulges inwards
wraps around particles
pinches off to form vesicle inside of cell

Question 22

is endocytosis and exocytosis active or passive

Answer 22

active
require ATP