(CELL BIO) Transport in cells

Question 1

Define diffusion

Answer 1

Movement of particles from an area of high concentration to an area of lower concentration

Question 2

What are the three main factors that affect the rate of diffusion?

Answer 2

• Concentration gradient
• Temperature
• Surface area

Question 3

How are single-celled organisms adapted for diffusion?

Answer 3

They have a large surface area to volume ration - maximises the rate of diffusion of molecules to meet the organism’s needs

Question 4

Define osmosis

Answer 4

Movement of water from a dilute solution to a concentrated solution through a partially permeable membrane

Question 5

Define active transport

Answer 5

Movement of molecules from a more dilute solution to a more concentrated solution against a concentration gradient, using energy from respiration

Question 6

how do plant root hair cells use active transport

Answer 6

Root hair cells use active transport to take up mineral ions from a more dilute solution in soils. Ions such as magnesium and nitrates are required for healthy growth.

Question 7

How is active transport used to absorb the products of digestion

Answer 7

Active transport is used to transport glucose from a lower concentration in the gut to a higher concentration in the blood. Glucose is then transported to the tissues where it can be used in respiration