1.3 Cell membrane and transport

Question 1

Function of cell membrane

Answer 1

-Structural support
-Secretes chemicals
-Cell recgonition
-Collects nutriens

Question 2

Name the 8 parts of the cell membrane

Answer 2

1. Gloycoprotein
2. Glycolypid (carbohydrate chain)
3. Phosphate head (hydrophilic head)
4. Fatty acid tail (hydrophoic tail)
5. Intrinsic protein (carrier or channel)
6. Extrinsic protein
7. Cholestrol (rigididy)
8. Phospholypid bilayer

Question 3

When looking at a cell membrane using a light microscope, how many lines does it apear as?

Answer 3

1

Question 4

When looking at a cell membrane using a electron microscope, how many lines does it apear as?

Answer 4

2

Question 5

Function of intrinsic protein

Answer 5

(accross both layers both layers)
Act as a carrier/channel proteins, enzymes + transprot -facilitated diffusion and active transport

Question 6

Function of extrinsic protein

Answer 6

Act as a receptor, antigen and recognition centers spam through
-stuctural suppot
-recognition site
-Receptor sites for homone attatchment

Question 7

Function of cholestrol

Answer 7

Rigididy - stabalize the cell and increases melting point

Question 8

Function of Glycoprotein

Answer 8

Help to recognise and atatch cells

Question 9

Function of Glycolypid

Answer 9

maintain stability and facilitate cell to cell intreaction
(outer layer)

Question 10

Glycocalyx

Answer 10

Provent the entery of pathogen into the cell outer layer of membrane glycolypids and glycoproteins are found

Question 11

Name the bond, reaction and the hydrophilic and hydrophobic part of a phospholipid

Answer 11

Ester bond
Condensation reaction
Hydrophobic - fatty acid tail
Hydrophilic - phosphate head

Question 12

Phospholipids

Answer 12

They can form layers
Hydrophilic heads
Hydrophobic tail - repel water
Allows lipid-solube molecules across, not water

Question 13

Whats the name of the model for the cell membrane?

Answer 13

Fluid mosaic model

Question 14

What part of the cell membrane represents the fluid in the fluid mosaic model?

Answer 14

Phosphholipids are free tp move in the membrane

Question 15

What part of the cell membrane represents the mosaic in the fluid mosaic model?

Answer 15

Proteins move on the surface of the membrane

Question 16

3 factors that affect the permeability of a cell membrane

Answer 16

1. Heat
2. Ethanol
3. pH

Question 17

How does heat affect the cell membrane?

Answer 17

denatures the membrane

(makes membrane more permeable - more holes in it)

Question 18

How does pH affect the cell membrane?

Answer 18

denatures the membrane

(makes membrane more permeable - more holes in it)

Question 19

How does ethanol affect the cell membrane?

Answer 19

Ethanol disolves the lipid components of the membrane

(makes membrane more permeable - more holes in it)

Question 20

Name the 6 modes of transoprt

Answer 20

1. Diffusion
2. Facilitated diffusion
3. Active transport
4. Co transport
5. Osmosis
6. Endo/Exocytosis

Question 21

Definition of diffusion

Answer 21

The passive movement of mlecules from a** high concentration to a low concentration** untill they are equally distributed

Question 22

Meaning of passive

Answer 22

Does not require energy

Question 23

6 factors that affect the rate of diffusion

Answer 23

1. Concentration gradient
2. Distance of travel
3. Surface area of a membrane
4. Thickness of exchange surface
5. Size of moecules
6. Temperature - Kenetic energy

Question 24

Examples of molecules that pass through the membrane by diffusion

Answer 24

CO2, O2

Small
Uncharged
Lipid solubles

Question 25

Definition of facilitated diffusion

Answer 25

The passive transfer of molecules/ ions down a concentration gradient
-high to low
-by carrier proteins in the membrane

Question 26

Examples of molecules that pass through the membrane by facilitated diffusion

Answer 26

Na+ K+, glucose, amino acids

Large
Charged
Water solubles

Question 27

Active transport defintition

Answer 27

Movement of ions/molecules accross the membrane from a low to high concentration against the concentartion gradient
Requires energy

Question 28

Factors that affect the rate of uptake - active transport

Answer 28

1. Respiritory inhibitor - Cyanide
2. Number of carrier proteins
3. Oxygen availability

Question 29

Co transport

Answer 29

Type of facilitated diffusion that brings molecules and ions into the cell together on the same transport protein
e.g Sodium and glucose co transport into cell together