1.3 - Membrane structure

Question 1

What is the function of the plasma membrane?

Answer 1

Selectively permeable and controls what enters and leaves the cell

Question 2

What is a phospholipid bilayer composed of?

Answer 2

Two layers of phospholipids (phosphates and fats)

Question 3

Is the tail hydrophobic or hydrophillic?

Answer 3

Hydrophobic

Question 4

How does the arrangement of the phospholipid bilayer protect the tails from water?

Answer 4

It forms an enclosed shape

Question 5

Where is cholesterol found in the plasma membrane?

Answer 5

Between phospholipids

Question 6

What is the function of cholesterol in the plasma membrane?

Answer 6

Reduces membrane fluidity in animal cells and restricts molecular motion

Question 7

What is a glycoprotein?

Answer 7

Short carbohydrate (less than 15 sugars) chains that covalently bond to proteins

Question 8

What is the function of a glycoprotein?

Answer 8

Provides cells a way to recognize other cells by binding to molecules

Question 9

What is an integral protein?

Answer 9

Protein that extends at least into the hydrophobic region

Question 10

What is a peripheral protein?

Answer 10

Proteins not embedded within the membrane (attached to external surface)

Question 11

What is one function of membrane proteins?

Answer 11

• Proteins have binding signals with signal molecules

- Binding causes protein to change shape releasing chemical signal allowing cells to communicate

Question 12

What is cell adhesion?

Answer 12

Membrane proteins can be used to connect another cell’s membrane protein

Question 13

What did the Davson-Danielli membrane model propose?

Answer 13

That there were layers of protein on both sides of the bilayer