The Cell Membrane

Question 1

List the 4 main functions the cell membrane has

Answer 1

1. Physical barrier 
    Separates inside of the cell (cytoplasm) from the outside (extracellular fluid).
2. Controls passage of materials 
     Entry/exit of molecules and substances
3. Senses changes 
     Contains receptors 
4. Supports structure 
     Attached to microfilaments.

Question 2

What is currently the most accepted model for the cell membrane

Answer 2

Fluid mosaic model

Question 3

What does fluid mean

Answer 3

molecules constantly moving

Question 4

What does mosaic mean

Answer 4

made of different types of molecules

Question 5

The cell membrane consists of…

Answer 5

a phospholipid bilayer
Cholesterol
Proteins

Question 6

Is the phosphate head hydrophobic or hydrophilic

Answer 6

hydrophilic

Question 7

Is the lipid tail hydrophobic or hydrophilic

Answer 7

hydrophobic

Question 8

What is the location of the phosphate head

Answer 8

Outside of the layer

Question 9

What is the location of the lipid tail

Answer 9

Inside of the layer

Question 10

Active transport across the cell…

Answer 10

Uses the cells energy

Question 11

Passive transport across the cell…

Answer 11

does not involve using the cells energy

Question 12

Example processes for active transport across a cell

Answer 12

facilitated transport

Vascular transport

Question 13

Example processes for passive transport across a cell

Answer 13

simple diffusion
Osmosis
Facilitated transport

Question 14

What is diffusion

Answer 14

The process of particles spreading out results in an even distribution of gases and liquids

Question 15

What is osmosis

Answer 15

The diffusion of a solvent through a differentially permeable membrane resulting in a balanced concentration.

Question 16

what is Vesicular transport

Answer 16

the movement of substances across the cell membrane in membranous sacs called vesicles

Question 17

what is Facilitated transport

Answer 17

Transport through proteins

Question 18

What is the process of carrier proteins

Answer 18

1. ) specific substance binds to a binding site
2. ) protein changes shape and opens up
3. ) substance is released on the opposite side

Question 19

Endocytosis…

Answer 19

entering the cell

Question 20

Exocytosis…

Answer 20

exiting the cell

Question 21

Phagocytosis

Answer 21

solid particles

Question 22

Pinocytosis…

Answer 22

liquid particles

Question 23

Is Facilitated diffusion along or against the concentration gradient

Answer 23

along (high->low)

Question 24

Is active transport along or against the concentration gradient

Answer 24

against (low->high)

Question 25

If we increase the rate of exchange across the cell membrane (surface area) would it increase or decrease in volume (cytoplasm)?

Answer 25

decrease

Question 26

If we increase the rate of exchange across the cell membrane would it increase or decrease in the surface area (cell membrane )?

Answer 26

increase

Question 27

If we increase the rate of exchange across the cell membrane (surface area) would it have a higher or lower concentration gradient?

Answer 27

a higher concentration gradient

Question 28

If we increase the rate of exchange across the cell membrane (surface area) would proteins be saturated (full) or partially occupied?

Answer 28

proteins are partially occupied

Question 29

If we increase the rate of exchange across the cell membrane (surface area) would temperature be increasing or decreasing?

Answer 29

temperature would increase