Transport

Question 1

Diffusion

Answer 1

Spreading out of particles resulting in a net movement from area of high concentration to low concentration

Question 2

Where does diffusion take place?

Answer 2

In and out of the cell membrane

Question 3

Examples of diffusion (gas exchange in cells)

Answer 3

Oxygen from blood (high concentration from lungs) into body cells (low concentration)
For aerobic respiration
But then have high concentration of co2 in cell
So co2 moves out via diffusion into bloodstream

Question 4

Urea

Answer 4

Waste product produced in cells from broken down ammonia
Diffuses out into the blood plasma then excreted

Question 5

Example of diffusion

Answer 5

Urea from breakdown of ammonia in cells (high concentration)
To blood plasma (low concentration)

Question 6

Factors affecting diffusion

Answer 6

Concentration gradient
Temperature
Surface area of membrane

Question 7

How does concentration gradient affect diffusion?

Answer 7

Concentration gradient (difference in concentration)
Quicker rate = larger concentration gradient

Question 8

How does temperature affect diffusion?

Answer 8

Quicker rate = warmer because have particles move faster with more energy thus quicker net movement of particles

Question 9

How does surface area affect diffusion?

Answer 9

Greater surface area = higher rate of diffusion
As more particles can diffuse at once

Question 10

Ósmosis

Answer 10

Diffusion of water from a dilute solution (lots of water) to a concentrated solution (little water)
Through partially permeable membrane

Question 11

What is the concentration gradient in osmosis?

Answer 11

Follows the concentration gradient
From many water particles to low water particles

Question 12

Partially permeable membrane

Answer 12

Allows some molecules to pass through
Such as water as they are smaller

Question 13

Ósmosis in animal cells by putting it in water

Answer 13

Low amount of water (concentrated) in the cytoplasm
Placing it in water = water will move into the cell by osmosis
Then expand

Question 14

What happens if an animal cell has too much water diffuse into it by osmosis?

Answer 14

It will expand then burst
As it contains to much water

Question 15

Ósmosis in animal cells by putting it in a concentrated solution

Answer 15

Water moves from the cell into the solution as the cell contains more water
Thus shrink

Question 16

Placing a plant cell in water

Answer 16

Will expand
But WONT burst as it becomes swollen instead = turgid
Because the cell all protects it from doing so

Question 17

Placing a plant cell in a concentrated solution

Answer 17

Will shrink
Because more water in the cell than the solution so ósmosis of particles out of the cell
Thus becomes flaccid

Question 18

When does active transport occur?

Answer 18

When a cell needs to bring a molecule into it that already has a high concentration of it inside the cell

Question 19

Active transport

Answer 19

The net movement of substances from a low concentration to a higher concentration
Thus going against the concentration gradient

Question 20

What does active transport require?

Answer 20

Energy from respiration

Question 21

Does diffusion require energy?

Answer 21

No

Question 22

Examples of active transport

Answer 22

Sugars From the small intestine to the bloodstream
Mineral ions from soil into root hair cells

Question 23

Active transport of sugars in small intestine

Answer 23

After digestion enters the lumen of small intestine
Moves into the blood stream through cells
Said cells contain many mitochondria for energy

Question 24

Active transport of mineral ions into root hair cells

Answer 24

Root hair cells contain many mitochondria for respiration
As concentration of ions in soil is lower than in the root hair cell