Key Definitions - Movement of substances in and out of cells

Question 1

define diffusion

Answer 1

the net movement of substances from an area of high to low concentration, down a concentration gradient and can be across a partially permeable membrane

Question 2

define osmosis.

Answer 2

the net movement of water from an area of high to low water potential, down a water potential gradient and can be across a partially permeable membrane

Question 3

define active transport.

Answer 3

the movement of substances from an area of low to high concentration, against a concentration gradient, using the energy from ATP

Question 4

define phloem.

Answer 4

a tissue in plants that is specialised to transport sugars and amino acids both up and down the plant from the leaves to respiring tissues. This is called translocation

Question 5

define translocation.

Answer 5

the movement of sugars and amino acids through the phloem

Question 6

define transpiration.

Answer 6

water loss via evaporation through the stomata in the leaves down a water potential gradient

Question 7

define transpiration stream.

Answer 7

the upwards movement of water through the xylem from roots to leaves

Question 8

define xylem.

Answer 8

a tissue that is specialised to transport water from the roots to the leaves. Is dead and hollow to allow the continuous column of water