2.4 - Transport Across Membranes

Question 2

Why is transporting materials in and out of the cell important

Answer 2

For survival
- rid of waste
- get nutrients
- communication (all via chemicals)

Question 3

Passive transport

Answer 3

movement of a substance
across the membrane without using energy

Question 4

What drives passive transport?

Answer 4

Diffusion

Question 5

Diffusion

Answer 5

Molecules/ions move from HIGH to LOW
concentrations

Question 6

Types of Passive Transport

Answer 6

Simple diffusion, facilitated diffusion, osmosis

Question 7

Simple Diffusion

Answer 7

movement of small/non-polar
substances across the membrane without using energy (CO2, O2)

Question 8

Facilitated Diffusion

Answer 8

Uses TRANSPORT PROTEINS which provide
pathways for movement across membrane

Question 9

Channel Protein

Answer 9

hydrophilic pathway/tube through
membrane

Question 10

Carrier Protein

Answer 10

physically binds to molecules to help transport

Question 11

Osmosis

Answer 11

the passive diffusion of water across a
membrane

Question 12

Osmosis moves from an area of

Answer 12

LOWER SOLUTE
CONCENTRATION (high water content) to an area
of HIGHER SOLUTE CONCENTRATION (low water
content)

Question 13

__________________ determines water movement

Answer 13

SOLUTE (dissolved substances)
CONCENTRATION

Question 14

True or False? The Concentration of Solutes around cells
determines their shape

Answer 14

True

Question 15

Hypotonic Solution

Answer 15

low concentration of
solutes outside cell = water rushes into cell

Question 16

Isotonic Solution

Answer 16

equal concentration of
solutes inside and outside of cell = no net
movement of water

Question 17

Hypertonic Solution

Answer 17

high concentration of
solutes outside cell = water rushes out of cell

Question 18

Active Transport

Answer 18

the movement of substances
across the membrane using energy

Question 19

True or false? Active transport movement is following the concentration gradient

Answer 19

False. Against

Question 20

What does active transport use to “pump” substances across

Answer 20

ATP

Question 21

Primary Active Transport

Answer 21

Move POSITIVELY CHARGED IONS across membranes (generally relying on ATP)

Question 22

Secondary Active Transport

Answer 22

Uses energy from the Concentration Gradient
built up by Primary Active Transport to
transport substances

Question 23

Symport

Answer 23

transported substances move in the
same direction as ions

Question 24

Antiport

Answer 24

transported substances move in the
opposite direction as ions

Question 25

Why is Exocytosis and endocytosis needed?

Answer 25

to transport substances larger than amino acids/monosaccharides

Question 26

Exocytosis

Answer 26

transport of substances from inside the cell to outside of the cell using vesicles

Question 27

Endocytosis

Answer 27

transport of substances from outside the cell to inside the cell using vesicles in one of three distinct pathways

Question 28

3 distinct pathways of endocytosis

Answer 28

Pinocytosis (cell drinking), Receptor-mediated Endocytosis, Phagocytosis (cell eating)

Question 29

Pinocytosis (cell drinking)

Answer 29

brings in fluid along with any molecules inside the fluid

Question 30

Receptor-mediated Endocytosis

Answer 30

has molecules bind to receptor proteins on the outer surface before coming into the cell

Question 31

Phagocytosis (cell eating)

Answer 31

brings in solid materials like bacteria, dead cells, or other foreign material