B3 movement into and out of cells

Question 1

define diffusion

Answer 1

• net mvmt of particles
• from region of their high concentration to region of their lower concentration
• as result of their random mvmt

Question 2

how do substances move into/out of cells

Answer 2

diffusion through cell membrane

Question 3

why is diffusion important in organisms

Answer 3

• to deliver or removed dissolved substances (solutes) and gases though cell membranes

Question 4

how does surface area influence diffusion

Answer 4

• as SA inc, diffusion inc

Question 5

how does temperature influence diffusion

Answer 5

• as temp inc, diffusion inc

Question 6

how does concentration gradient influence diffusion

Answer 6

• as inc, diffusion inc

Question 7

how does distance influence diffusion

Answer 7

• as distance inc, diffusion dec

Question 8

how does water diffuse through partially permeable membranes

Answer 8

osmosis

Question 9

how does water move in/out of cells

Answer 9

through partially permeable membranes by osmosis

Question 10

what happens to water in a cell if placed in concentrated solution

Answer 10

water will leave cell

Question 11

what happens to water in a cell if placed in a dilute solution

Answer 11

water will enter cell

Question 12

define osmosis

Answer 12

• net mvmt of water moelcules
• from regionof high wp (dilute solution) to low wp (concentrated solution)
• through a partially permeable membrane

Question 13

what happens if plant cell is immersed in dilute solution

Answer 13

• gain water by osmosis
• turgor pressure increases
• high tp = turgid

Question 14

what happens if plant cell is immersed in concentrated solution

Answer 14

• lose water by osmosis
• turgor pressure decreases
• becomes flaccid
• if lose a lot of water, cytoplasm/vacuole may shrink so much that cytoplasm pulls away from cell wall (plasmolysis)

Question 15

why is osmosis important in plants

Answer 15

• water in soil (dilute solution)
• enter root hair cell by osmosis

Question 16

why is osmosis important in animals

Answer 16

• body cells can be damaged if too much/little water gained/lost
• so, water concentration of blood/cytoplasm v closely controlled by kidneys

Question 17

define active transport

Answer 17

• mvmt of particles thru cell membrane
• region of low conc to region of high conc
• using energy from respiration

Question 18

active transport in plants

Answer 18

• conc of ions higher inside root hair cell than soil
• diffusion would cause ions to move out of plant
• AT allow take in vital ions

Question 19

active transport in animals

Answer 19

• glucose absorbed thru intestine wall into bloodstream
• when glucose conc in intestine < bloodstream, active transport