TV4 - Ch.5: Membrane transport

• Biologie
• Middelbare school
• vwo
• Leerjaar 4

Membrane transport

TV4

Chapter 5

Learning goals

• You can explain how a membrane is built
• You can explain that a membrane is semi permeable
• You can explain how, by means of diffusion and osmosis, compounds can pass through the cell membrane
• You can explain what consequences this transport might have for cells

Write down a similarity between diffusion and osmosis.

Write down two differences between diffusion and osmosis.

Someone adds a hypertonic solution to red blood cells of cows.
Eventually these cells will...

1. swell as a result of osmosis until they burst
2. shrink as a result of osmosis
3. not gain or lose any water at all

If you eat a bag of crisps...

1. the osmotic value of your blood rises
2. the osmotic value of your blood remains the same
3. the osmotic value of your blood drops

Explain why you get thirsty when you eat a bag of crisps.
Make sure you include 'osmotic value' in your answer.

The cell membrane comprises of two layers of phospholipids

Hydrophylic out- and inside

Hydrophobic layer in between

Not permeable to water

aquaporine

A protein channel that allows the diffusion of water in and out the cell

facilitated diffusion

diffusion is made easer by protein channels through the cell membrane

01:51

What molecules can pass the cell membrane without any difficulty?

1. charged particles / ions
2. glucose
3. water
4. oxygen and carbondioxide

02:14

'With the concentration gradient' means from...

1. a higher concentration to a lower
2. a lower concentration to a higher

04:51

Active transport requires...

04:51

In what organelle is the energy-rich ATP generated?

06:52

Pancreatic cells (alvleeskliercellen) create enzymes. When these proteins are completed, they need to be excreted.

By what way do enzymes leave the pancreatic cells?

1. simple diffusion
2. facilitated diffusion
3. active transport
4. exocytosis

Osmose in animal cells

hypotonic solution OUTSIDE the cells

water enters the cell through osmosis, causing the cells to swell and burst

isotonic solution OUTSIDE the cells

no osmosis because there is no gradient

hypertonic solution OUTSIDE the cells

water leaves the cells through osmosis causing them to shrink

Osmose in plant cells

hypotonic solution OUTSIDE the cells

water enters the cell through osmosis. The cells becomes rigid

TURGOR

isotonic solution OUTSIDE the cells

no osmosis because there is no gradient

hypotonic solution OUTSIDE the cells

water leaves the cell through osmosis. The cells becomes flaccid: PLASMOLYSIS

The cell left is ....
The cell right is ....

1. left = turgid right = plasmolysed
2. left = plasmolysed right = turgid

A ... solution is added to the left sample which causes the cells to become turgid

1. hypertonic
2. isotonic
3. hypotonic

A ... solution is added to the right sample, causing the cells to become plasmolysed.

1. hypertonic
2. isotonic
3. hypotonic

Learning goals

• You can explain how a membrane is built
• You can explain that a membrane is semi permeable
• You can explain how, by means of diffusion and osmosis, compounds can pass through the cell membrane
• You can explain what consequences this transport might have for cells