B6 Cell membrane

Question 1

Which one is hydrophilic and which one is hydrophobic between phosphate head and tail ( fatty acid chain) ?

Answer 1

Phosphate head is hydrophilic (polar) and tail is hydrophobic (non-polar)

Question 2

What is the cell membrane?

Answer 2

A barrier between cell and environment which is partially permeable

Question 3

What are the three transport methods to pass through the cell membrane?

Answer 3

• Active transport
• Diffusion
• Osmosis

Question 4

Why is the cell membrane called fluid mosaic?

Answer 4

It is called ‘fluid’ because the molecules within the membrane are able to move around
It is called ‘mosaic’ because it is made from a variety of different molecules arranged into a mosaic

Question 5

What is the definition of osmosis?

Answer 5

The net movement of water particles from a high water potential to a low water potential across a partially permeable membrane

Question 6

What number means there is a high water potential?

Answer 6

0

Question 7

What number means a low water potential?

Answer 7

negative

Question 8

What water potential does pure water have?

Answer 8

high (0)

Question 9

What does isotonic mean?

Answer 9

When water potential is the same inside and outside the cell
-Solutions of equal solute concentration

Question 10

What does hypertonic mean?

Answer 10

It is the solution with the higher solute concentration

Question 11

Why does hypotonic mean?

Answer 11

The solution with the lower solute concentration

Question 12

What are the words for outside and inside of the cell?

Answer 12

• Extracellular and Intracellular

Question 13

What is the layer that makes up the cell membrane called?

Answer 13

Phospholipid bilayer

Question 14

What happens in between phospholipid bilayer?

Answer 14

Simple diffusion which is passive and is from high to low concentration

Question 15

What specific characteristics are needed for particles to pass through the phospholipid bilayer?

Answer 15

The molecules need to be small, soluble and uncharged

Question 16

What is the function of channel proteins?

Answer 16

To transport small, charged (ions) and soluble molecules quickly through the membrane.

Question 17

What is the transport method in the channel protein?

Answer 17

Facilitated diffusion which occurs from high to low concentration and it is passive and requires help from proteins

Question 18

What is the function of carrier proteins?

Answer 18

Molecules bind to them and which changes the tertiary structure of carrier proteins

Question 19

What sort of molecules can pass through carrier proteins?

Answer 19

Large molecules eg. glucose or amino acids

Question 20

What transport methods occur in carrier proteins?

Answer 20

Facilitated diffusion and active transport

Question 21

What does the cholesterol in the phosphate bilayer do?

Answer 21

Adds rigity to the bilayer

Question 22

What do receptors do in the cell membrane?

Answer 22

Allows signaling molecules to attach to them to trigger a response , they have complimentary shapes

Question 23

What is the role of enzymes in the cell membrane?

Answer 23

They hydrolyse bonds between molecules so that they can pass through the membrane eg. dipeptides into amino acids