movement of substances into and out of cells

Question 1

diffusion

Answer 1

the net movement of particles from an area of high concentration to an area of low concentration.
particles have moved down a concentration gradient
(until equilibrium is reached)

Question 2

osmosis

Answer 2

net movement of water across a partially permeable membrane, from a solution with a high concentration of water to one with a lower concentration of water.
(until equilibrium is reached)

Question 3

active transport

Answer 3

movement of ions (eg nitrate) & molecules (eg sugar) move across a cell membrane against the concentration gradient (low to high) and therefore require an input of energy from the cell, the energy changes the shape of the carrier protein.

Question 4

factors increasing the rate of diffusion

Answer 4

• higher the temperatures (because the particles have more kinetic energy)
• when there’s a bigger concentration gradient
• across a bigger surface area (the larger the surface area to volume ratio, the longer it takes)

Question 5

factors affecting the rate of osmosis

Answer 5

-the volume of acid

Question 6

factors affecting the rate of active transport

Answer 6

-

Question 7

osmosis in plant/ animal cells in PURE WATER

Answer 7

-higher concentration of water outside the cell,
-water will move INTO cell by osmosis.
ANIMAL- swell and LYSE (explode)
PLANT- become TURGID (not explode because have a cell wall)

Question 8

osmosis in plant/ animal cells in CONCENTRATED SOLUTION

Answer 8

-higher concentration of water inside the cells
- water will move OUT of cell by osmosis
ANIMAL- shrink
PLANT- become FLACCID (limp) and PLASMOLYSED (cell membrane pull away from cell wall)

Question 9

sugar level in tube experiment

Answer 9

VISKING TUBING- acts like partially permeable membrane
tubing filled with strong sugar solution
surrounded by a weak sugar solution
glass tube shows level of sugar solution in tubing
The sugar level IN THE TUBING will go DOWN because there is a LOWER CONCENTRATION of water inside the tubing and the water will move from a high conc to a low conc.

Question 10

CORMMS for diffusion

Answer 10

how the temp affects rate
C- temp.
O- agar
R- 3 times 
M- 4 different temp. environments
M- which agar turned fully red of HCL first
S- the volume of agar
The LARGER the SURFACE AREA to VOLUME RATIO, the SLOWER the rate is.

Question 11

CORMMS for osmosis

Answer 11

mass of potato in varied % of salt water
C- % of salt water
O- potato tubes
R- 3 pieces of potato per %
M- 5 different % (pure, 5, 10, 15, 20% salt)
M- the mass change of potato
S- the volume of beginning potato.
The HIGHER the salt % conc in water, the LESS the mass of the potato was.

Question 12

why unicellular organisms rely on diffusion for movement of substances in and out of the cell

Answer 12

they need to gain nutrients but don’t have energy (dont respire) so cant move by active transport.
the cells have a lower concentration of nutrients so they move through the partially permeable membrane.