Osmosis

Question 1

What is diffusion?

Answer 1

Diffusion is the movement of molecules from a higher concentration to a lower concentration down a concentration gradient, it is a form of positive transport (no energy required) - the molecules eventually become evenly dispersed.

Question 2

What is an example of diffusion?

Answer 2

02 diffuses into blood and CO2 diffuses out.

Question 3

What are the factors affecting rate of diffusion?

Answer 3

Concentration gradient, distance moved, surface area involved, barriers to diffusion, temperature

Question 4

How does concentration gradient effect the rate of diffusion?

Answer 4

Rate of diffusion is higher when there is a greater difference between the concentrations of two regions.

Question 5

How does distance moved effect the rate of diffusion?

Answer 5

Diffusion over a shorter distance occurs at a greater rate than over a large distance.

Question 6

How does surface area effect the rate of diffusion

Answer 6

The larger the area, the greater the rate of diffusion.

Question 7

How does barriers to diffusion effect the rate of diffusion

Answer 7

Thick barriers have a slower rate of diffusion than thin barriers.

Question 8

How does temperature effect the rate of diffusion

Answer 8

Higher the temperature, the more diffusion occurs

Question 9

Define osmosis

Answer 9

Osmosis is the diffusion of water particles from a higher concentration of water to a lower concentration of water (lower so,ute concentration to a higher solute concentration) across a semi permeable membrane, it is a form of passive transport ( no energy required) - the water molecules eventually become dispersed.

Question 10

Give an example of osmosis

Answer 10

Water and iodine solution diffuses into Starc, starch goes blue back with iodine

Question 11

What is isotonic

Answer 11

Concentration of water is the same intracellular and extracellular. Movement is equal therefore there is no change in the cell size.

Question 12

What is hypertonic

Answer 12

Concentration of water higher intracellular, lower extracellular. Water will move from inside the cell to outside the cell, therefore the cell will shrink

Question 13

What happens to an animal cell when it is hypertonic?

Answer 13

Water will move out of the cell and the cell wall will shrink = crenate

Question 14

What happens to a plant cell when it is hypertonic

Answer 14

Water will leave the cell and the cytoplasm will shrink and plasmolyse, become flaccid

Question 15

What is hypotonic

Answer 15

Concentration of water is lower intracellular, higher extracellular. Therefore water will move from outside the cell to inside the cell, cell expands

Question 16

What happens to animal cell in hypotonic solution

Answer 16

Water enters the cell, cell swells and may burst or lyse

Question 17

What happens to a plant cell in a hypotonic solution?

Answer 17

Water enter the cell, cell swells a bit and becalmed turgid due to Ce,, wa,, preventing the cell from bursting

Question 18

What is the definition of enzymes

Answer 18

Biological catalysts that speed up the rate of metabolic reactions