Osmosis 2

Question 1

What % of some organisms bodies can be made of water?

Answer 1

Up to 80%

Question 2

Name the 3 key roles of water in the body

Answer 2

1. Solvent for digestion (enzymes + food dissolve in it)
2. Excretes urea in urine
3. Transports substances in blood plasma

Question 3

Where is water found in the body’s cells?

Answer 3

Inside and outside every cell

Question 4

Why do substances move in/ out of cells?

Answer 4

Due to concentration gradients inside and outside cell

Question 5

What happens when a solute can pass through a membrane?

Answer 5

It diffuses from high to low concentration

Question 6

Why can water diffuse through dialysis tubing but sugar can’t?

Answer 6

Water molecules are much smaller than sugar molecules

Question 7

What is a partially permeable membrane?

Answer 7

One that allows some molecules (like water) through but blocks others (like sugar

Question 8

What causes water to move across a membrane in sugar solutions?

Answer 8

Water moves from high concentration to low concentration (osmosis) due to more water on the dilute side

Question 9

Why is water being a solvent important in digestion?

Answer 9

It allows enzymes and nutrients to dissolve and react

Question 10

What’s the difference between osmosis and diffusion?

Answer 10

1. Diffusion is the movement of ANY particles from a high to low concentration
2. Osmosis is the movement of WATER ONLY across a partially permeable membrane