Cell Membrane

Question 1

What is a general term for all biological membranes found inside the cell?

Answer 1

Cell membrane

Question 2

Who proposed the fluid-mosaic model as structure of the cell membrane in 1972? It is also another name of the model.

Answer 2

Singer & Nicolson (Singer-Nicolson model)

Question 3

Why is it called a fluid-mosaic model?

Answer 3

Due to the fluid nature of the cell membrane. It is not rigid and its components also move across the membrane.

Question 4

What does mosaic mean in the fluid-mosaic model?

Answer 4

The components have different shapes and sizes, appearing like mosaic art.

Question 5

One of the components of the cell membrane, which has a head and two tails.

Answer 5

Phospholipid bilayer

Question 6

A component of the cell membrane, which can be classified into two types, 1. peripheral (surface) and 2. integral (transmembrane) _____

Answer 6

Membrane proteins

Question 7

Another component of the cell membrane, which has two classifications: 1. glycoproteins and b. glycolipids

Answer 7

Membrane carbohydrates

Question 8

The component of the cell membrane primarily responsible for the fluidity of the membrane

Answer 8

Cholesterol

Question 9

The phospholipid bilayer has two components, a ____ head which means ____?

Answer 9

Hydrophilic, water-loving

Question 10

The other component of the phospholipid bilayer, the two ___ fatty acid tails, which means it’s ____?

Answer 10

Hydrophobic, water-resistant

Question 11

The phospholipid bilayer is called that because it is composed of two layers of ____?

Answer 11

Phospholipid molecule

Question 12

Substances that exhibit both hydrophobic and hydrophilic properties are called?

Answer 12

Amphipathic

Question 13

Where can the peripheral proteins be found? It is also another name for it.

Answer 13

Surface

Question 14

What binds the peripheral proteins?

Answer 14

Hydrophilic bonds

Question 15

Integral proteins penetrate how far in the bilayer?

Answer 15

Partly or all the way through

Question 16

Glycoproteins are made of?

Answer 16

Peripheral proteins + oligosaccharides (sugar)

Question 17

Glycolipids are made of?

Answer 17

Phospholipids (lipids) + oligosaccharides (sugar)

Question 18

The membrane carbohydrates (glycoproteins & glycolipids) are essential to what cell membrane function?

Answer 18

Cell to cell recognition

Question 19

Cholesterol are found where?

Answer 19

Interspersed (scattered) within the phospholipid bilayer

Question 20

In high temperatures, what does cholesterol do?

Answer 20

Turn firm, solid

Question 21

In low temperatures, what does cholesterol do?

Answer 21

Turn fluid, soft

Question 22

What function does the phospholipid bilayer provide?

Answer 22

Affects the fluidity and permeability of the cell membrane

Question 23

What function do the proteins of the cell membrane provide?

Answer 23

Structural support, function in active transport, enzyme recognition site, carries enzymes and electrons

Question 24

Other than being a cell recognition site, what do glycolipids offer in function?

Answer 24

Supports stability in the membrane

Question 25

The functions of the cell membrane, name one (or all of them)

Answer 25

Possible answers:
1. Forms a boundary from the interior of the cell (cytoplasm) from the outside (phospholipid bilayer)
2. Gives shape, strength and protection to the cell
3. Regulates and controls flows of materials in and out of the cell (phospholipid bilayer)
4. Provides receptor sites to detect chemical messengers (communication)
5. Cell to cell recognition site (membrane carbohydrates)
6. Joins cells together in an organ
7. Enables attachment of organelles to cytoskeleton of the cell
8. Attachment sites for enzymes (proteins)
9. Divides a cell into separate compartments (enables compartmentalization)
10. Has a role in intracellular transport system (proteins)