Movement Of Substances Into Or Out Of Cells

Question 1

What is diffusion?

Answer 1

The net movement of particles from a region of higher concentration to lower concentration as a result of random movement

Question 2

How does diffusion help living organisms?

Answer 2

• obtain many of their requirements
• get rid of many waste products
• carry out gas exchange for respiration

Question 3

Factors affecting rate of diffusion

Answer 3

• shorter distance
• higher temperature
• higher concentration gradient

Question 4

What is osmosis?

Answer 4

The diffusion of water molecules from region of high water potential to lower water potential through a partially permeable membrane

Question 5

What are the three types of osmosis?

Answer 5

Hypertonic, isotonic, hypertonic

Question 6

What is hypotonic osmosis and what does it do?

Answer 6

• more water than solute (dilute)
• water enters the cell
• causes animal cell to swell and burst
• causes plant cell to be turgid

Question 7

What is isotonic osmosis and what does it do?

Answer 7

• salt solution (50/50)
• animal cell and plant cell has same amount of water entering and leaving the cell

Question 8

What is hypertonic osmosis and what does it do?

Answer 8

• more solute than water (concentrated)
• water leaves the cell
• causes animal cell to shrivel and shrink
• causes plant cell to be flaccid then plasmolysed

Question 9

What is active transport?

Answer 9

Movement of particles through a cell membrane from a region of lower to higher concentration using energy from respiration

Question 10

Where does active transport happen?

Answer 10

At the roots of a plant

Question 11

Steps for active transport

Answer 11

1. Glucose molecule enters carrier protein
2. Carrier protein changes shape
3. Carrier protein pushes glucose molecule into the cell