M&R 1.1 - The Membrane Bilayer Flashcards Preview

ESA 2 > M&R 1.1 - The Membrane Bilayer > Flashcards

Flashcards in M&R 1.1 - The Membrane Bilayer Deck (22):
1

What are the functions of the bilayer? (5)

- Continuous and selective permeable barrier
- Control chemical environment inside
- Communication
- Recognition
- Signal generation in response to stimuli

2

What is the dehydrated composition of the membrane?

- 40% Lipid
- 60% Protein
- 1-10% Carbohydrate

3

How does the hydrated composition of the membrane differ from the dehydrated composition?

Hydrated is 20% water

4

What is the significance of water in the Bilayer?

- Bonds to Bilayer with hydrogen bonds
- Facilitates hydrophilic interactions

5

Which 3 lipids are involved in the membrane?

- Phospholipids
- Glycolipids
- Cholesterol

6

Describe the head of a phospholipid molecule

- Hydrophilic
- Polar
- Negative

7

Describe the fatty acid chains of a phospholipid molecule

- Hydrophobic
- Uncharged
- Non-polar
- Cis double bond causes a kink

8

What is the advantage of phospholipids in the bilayer?

Increases the fluidity therefore allowing it to be ever-changing

9

How do Glycolipids differ from phospholipids?

The phosphocholine moiety is replaced with a sugar group

10

What is a Glycolipid with a sugar monomer called?

Cerebroside

11

What is a Glycolipid with an oligosaccharide chain called?

Ganglioside

12

What is the advantage of the similarity between phospholipids and Glycolipids?

Creates a constant environment for membrane proteins

13

Describe the head group of a cholesterol molecule

- Polar
- Hydrophilic
- Hydroxyl

14

Describe the tail group of a cholesterol molecule

- Aliphatic
- Non-polar

15

Describe the conjugated ring structure of a cholesterol molecule

- Planar
- Single bonds that are rigid

16

What is the significance of cholesterol molecules in the bilayer?

- Form hydrogen bonds with phospholipids
- Increases stability of the environment
- Decreases movement therefore decreasing fluidity
- Controls fluidity of bilayer

17

How are micelles and the lipid Bilayer formed?

Spontaneously in water

18

What are the 4 movements in the dynamics of the lipid bilayer?

- Flexion
- Rotation
- Lateral Diffusion
- Flip-flop

19

Describe Flexion in relation to the membrane

Fatty acids are able to move left or right

20

Describe rotation in relation to the membrane

Fatty acids can rotate around

21

Describe lateral diffusion in relation to the membrane

Fatty acids are able to swap places (common)

22

Describe flip-flop in relation to the membrane

- Lipids move from one side to the other
- One for one exchange
- Rare as not thermodynamically stable

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