bio chapter 2

Question 1

definition of diffusion

Answer 1

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

Question 2

factors affecting rate of diffusion

Answer 2

1. concentration gradient
2. diffusion distance
3. surface area to volume ratio

Question 3

definition of facilitated diffusion

Answer 3

diffusion of substances across cell membranes where there is a net movement of particles using specific protein channels or carriers from a region of higher concentration to a region of lower concentration

Question 4

definition of osmosis

Answer 4

net movement of water molecules from a region of higher water potential to a region of lower potential through a selectively permeable membrane

Question 5

definition of active transport

Answer 5

process in which cellular energy in the form of adenosine triphosphate 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 6

key features of active transport

Answer 6

1. occurs against concentration gradient
2. utilises metabolic energy in the form of adenosine triphosphate
3. active uptake is a highly selective process
4. takes place using transport proteins at membrane

Question 7

where does active transport occur at?

Answer 7

1. cell surface membrane of root hair cells to absorb mineral ions needed
2. cell surface membrane of intestinal epithelial cells to absorb nutrients e.g. glucose and amino acids needed