Fluid mosaic model (Cell membrane structure)

Question 1

Phospholipids

Answer 1

• Arrange themselves spontaneously in a bilayer due to hydrophobic interactions with the tails and H- Bonds with the heads
• Exterior phospholipids are more positive, interior are more negative

-Contribute to membrane fluidity

-Move laterally in the membrane and sometimes (rarely) flip flop

Question 2

Micelles

Answer 2

Formed by fatty acids with oen hydrophobic chain (looks kinda like a bowl)

Question 3

Liposomes

Answer 3

Looks kinda like a donut

Question 4

Cholesterol

Answer 4

• Also contributes to membrane fluidity at temperature extremes
• As temp decreases cholesterol pushes apart the phospholipids

-As temp increases it pulls the phospholipids closer

Question 5

Membrane fluidity in plants

Answer 5

• Plants lack cholesterol in their membrane
• Decreased temp, plants increase their synthesis of of unsaturated fatty acids
• Increased temp plants decrease their synthesis of saturated fatty acids

(unsaturated = double bonds)

Question 6

Glycolipid

Answer 6

(sugar = a phosphate)
- Are thought to be involved in cell to cell recognition and/or cell adhesion

Question 7

Integral membrane proteins

Answer 7

Go through the whole membrane

Question 8

Function of integral membrane proteins

Answer 8

1. Transport of nutrients and ions
2. Cell-cell communication (gap junction)
3. Attachment

Question 9

Glycoprotein

Answer 9

A protein with a carbohydrate attached to it

Question 10

Peripheral protein

Answer 10

A protein attached to another protein but doesn’t go through the membrane

Question 11

Lipid anchored protein

Answer 11

Attach to the lipid in the bilayer