Cell Membranes

Question 1

Intracellular fluid (ICF)

Answer 1

fluid within the cell

Question 2

Extracellular fluid (ECF)

Answer 2

interstitial (ISF) + plasma

Question 3

Interstitial fluid (ISF)

Answer 3

fluid that fills narrow spaces between cells of tissues

Question 4

Plasma

Answer 4

liquid portion of blood

Question 5

Fluid compartments

Answer 5

M: (60/40 fluid/solid)

• of fluids, 2/3 is intracellular fluid (ICF) and 1/3 is extracellular fluid (ECF)
• of ECF, 80% is interstitial fluid and 20% is plasma

Question 6

What makes up the structure of a cell’s membrane?

Answer 6

Phospholipid bilayer

Question 7

Explain the phospholipid bilayer

Answer 7

• amphipathic = has polar heads and non-polar tails

Question 8

Membrane permeability

Answer 8

• selective permeability: permits some substances to pass more readily than others
• highly permeable: O2, CO2 and steroids
• moderately permeable to small, uncharged polar molecules (water and urea)
• impermeable to ions and large, uncharged polar molecules (glucose)

Question 9

Types of transport across a membrane

Answer 9

1. Passive transport

2. Active transport

Question 10

Passive transport

Answer 10

• high to low concentration gradient

- no energy

Question 11

Active transport

Answer 11

• low to high concentration gradient

- requires energy

Question 12

Types of passive transport

Answer 12

1. Diffusion
2. Osmosis
3. Channel mediated facilitated diffusion
4. Carrier facilitated diffusion

Question 13

Diffusion

Answer 13

net movement of solutes from a region of greater concentration to a region of lesser concentration

Question 14

Osmosis

Answer 14

• water follows solvent

Question 15

Define tonicity

Answer 15

the effect of a solution on a cell shape

Question 16

Hypotonic solution

Answer 16

• water goes into cell -> lysis

Question 17

Hypertonic solution

Answer 17

• water leaves cell -> crenate

Question 18

Isotonic solution

Answer 18

• same concentration ECF and ICF