Diffusion + Osmosis

Question 1

Name the three things that diffusion depends on

Answer 1

1) distance- shorter=quicker
2) concentration- diffuse faster with a bigger difference in concentration
3) surface area- larger surface area=quicker

Question 2

True or false: during diffusion and osmosis the particles move both ways through a partially permeable membrane

Answer 2

True- however if there are a lot more particles on one side of the membrane there’s a net (overall) movement

Question 3

What things can and can’t fit through cell membranes?

Answer 3

Only small particles can fit though e.g. Amino acids, glucose, water and oxygen
Developed molecules cannon fit though e.g. Proteins and starch

Question 4

What is the definition of osmosis?

Answer 4

Osmosis is the movement of water molecules across a partially permeable membrane from a region of high water concentration it a region of low water concentration

Question 5

Describe how water moves in and out of cells by osmosis

Answer 5

1) tissue fluid surrounds the cells (sugar solution)
2) the tissue usually has a different concentration to the fluid inside a cell
3) if the cell is short of water, the solution inside will be very concentrated and so water will move into the cell by osmosis
4) if the cell has too much water, the solution inside the cell will be dilute and water will be drawn out of the cell by osmosis

Question 6

What is the definition of diffusion?

Answer 6

The passive movement of particles from an area of high concentration to an area of low concentration