Chapter 2: Movement Of Substances

Question 1

Concentration gradient

Answer 1

difference in concentration between 2 regions

Question 2

Diffusion

Answer 2

net movement of particles from a higher region of concentration to a lower region of concentration, down a concentration gradient

Question 3

Factors affecting rate of diffusion

Answer 3

1. Concentration gradient
2. Diffusion distance (shorter diffusion distance, less time taken for particles to diffuse, rate of diffusion higher)
3. Surface area-to-volume ratio (greater SA:V of a cell, higher rate of which substances move in & out of it)

Question 4

Osmosis

Answer 4

net movement of water molecules from a higher water potential to a lower water potential, across a partially permeable membrane

Question 5

water potential

Answer 5

measure of tendency of water molecules to move from one place to another

Question 6

water moves into cell

Answer 6

vacuole increases in size, cell expands/swells -> becomes turgid

Question 7

water moves out of cell

Answer 7

cell loses water, vacuole decreases in size, cell decreases in size -> flaccid/limp

Question 8

Active Transport

Answer 8

energy is used to move particles of a substance, across a membrane against its concentration gradient, from a region of lower concentration to a region of higher concentration

Question 9

where does AT occur

Answer 9

1. uptake of glucose by microvilli in epithelial cells in small intestine, & from up kidney tubules into blood capillaries
2. root hair cells taken in mineral salts from soil solution thru AT or diffusion, depending on soil concentration