Movement of materials in and out of the cells

Question 1

what is diffusion

Answer 1

diffusion is the net movement of particles (molecules or ions) from a region of high concentration to a region of low concentration i.e. down a concentration gradient.

Question 2

what do we need diffusion for

Answer 2

bringing things into the cell (e.g. oxygen, glucose, and amino acids). it is also used to send things out of the cell (e.g. carbon dioxide, urea, and hormones). water comes in and out

Question 3

when does it happen (diffusion)

Answer 3

when a substance is more concentrated in one place than another (the concentration gradient)

Question 4

what are things that affect the rate of diffusion

Answer 4

temperature
distance
concentration gradient
surface area to volume ratio

Question 5

what is active transport

Answer 5

active transport is the movement of substances against a concentration gradient, using energy from respiration

Question 6

when does it happen (active transport)

Answer 6

it happens when a cell already has a lot of a substance but needs more so it uses energy from respiration to move against the concentration gradient and transport more of that substance into the cell

Question 7

what is osmosis

Answer 7

osmosis in cells is the net movement of water from a dilute solution to a more concentrated solution across the partially permeable cell membrane.

Question 8

what happens in osmosis

Answer 8

when water moves from a place of high water potential (very dilute meaning a lot of water molecules or only water molecules giving the molecules free room to move around) to a place of low water potential (not very dilute lots of other molecules floating around, like sugar, cramping the water molecules) across a partially permeable cell membrane