Plasma Membrane + Transport Systems

Question 1

What is the main function of the plasma membrane?

Answer 1

Tao separate the inside ang outsize of the cell.

Question 2

What is the special characteristic that plasma membranes have?

Answer 2

Semi-Permeable; phospholipid bilayer

Question 3

What is the most abundant lipid at the plasma membrane?

Answer 3

Phospholipid

Question 4

What is the Fluid Mosaic Model?

Answer 4

Phospholipid (fluid) + Protein, Carbohydrates, Cholesterol (mosaic)

Question 5

Phospholipids are AMPHIPATHIC. What does that mean?

Answer 5

It has both hydrophobic ang hydrophilic properties.

Question 6

What is the difference between surface and peripheral protein?

Answer 6

Surface (permanent); Peripheral (temporary)

Question 7

What are the factors that affect membrane fluidity?

Answer 7

Temperature and Cholesterol

Question 8

What happens to the membrane when the temperature is higher?

Answer 8

Unsaturated hydrocarbon tails become more permeable

Question 9

What happens to the membrane when the temperature is lower?

Answer 9

It becomes more solid. Saturated hydrocarbon tails become more packed together

Question 10

What is the role of cholesterol in the plasma membrane?

Answer 10

Homeostasis and adaptability. Cholesterol reduces fluidity at higher temperatures and hinders solidification in lower temperatures.

Question 11

How could some organisms adapt in extreme conditions?

Answer 11

Evolution of differences in membrane lipid composition.

Question 12

What are the 2 main kinds of protein at the plasma membrane?

Answer 12

Integral and peripheral

Question 13

What is the main function of peripheral proteins?

Answer 13

1. Transport
2. Enzymatic activity
3. Signal transduction
4. Cell to cell recognition
5. Intercellular joining
6. Ecm

Question 14

What is the roles of carbohydrates in plasma membranes?

Answer 14

Cell to cell recognition. It can bond to lipids or more commonly proteins. Important in tackling diseases.

Question 15

What are the 2 main kinds of transport mechanisms?

Answer 15

Active and Passive

Question 16

What does active transport mean?

Answer 16

Needs atp; goes against concentration gradient

Question 17

What does passive transport mean?

Answer 17

Doesn’t need atp

Question 18

What is diffusion?

Answer 18

High to low concentration

Question 19

What is facilitated diffusion?

Answer 19

Assisted by TRANSPORT PROTEIN to speed up process.

Question 20

What is osmosis?

Answer 20

Diffusion of water. Water moves at the higher concentration of solute.

Question 21

What is tonicity?

Answer 21

Ability of solution to gain/lose water

Question 22

What is isotonic?

Answer 22

Equal water in and out (flaccid)

Question 23

What is hypotonic?

Answer 23

More water inside (turgid)

Question 24

What is hypertonic?

Answer 24

Less water inside. (Plasmolyzed)

Question 25

Describe exocytosis and endocytosis.

Answer 25

Exocytosis - out the cell; endocytosis - in to the cell

Question 26

According to the fluid mosaic model of cell membranes, phospholipids ________.

Answer 26

can move laterally along the plane of the membrane

Question 27

Which of the following types of molecules are hydrophilic and therefore excluded from the hydrophobic portion of the phospholipid bilayer?

Answer 27

peripheral membrane proteins

Question 28

According to the fluid mosaic model, a membrane ________

Answer 28

is composed of a fluid bilayer of phospholipids with embedded amphipathic proteins

Question 29

For a protein to be an integral membrane protein, it would have to be ________.

Answer 29

exposed on only one surface of the membrane

Question 30

A phospholipid bilayer with equal amounts of saturated and unsaturated fatty acids displays a specific permeability to glucose. What effect will increasing the proportion of unsaturated fatty acids in the bilayer have on the membrane's permeability to glucose?

Answer 30

Permeability to glucose will increase.