Chapter 7 Plasma Membrane

Question 1

Properties of single phospholipid

Answer 1

hydrophilic head, hydrophobic lipid tail, 3 parts

Question 2

components of plasma membrane

Answer 2

-phospholipid bi-layer
- selective permeability
-proteins (integral and …)
-cholesterol
-glycolipids and glycoproteins

Question 3

describe the arrangement of phospholipids in plasma membrane

Answer 3

totally random, the hydrophobic tails stop moving around when they come around another tail; self assembly forming a bi-layer

Question 4

selective (differential) permeability

Answer 4

membrane picks and chooses what enters and leaves

Question 5

what kind of solvent does the plasma membrane occur

Answer 5

aqueous

Question 7

what factors determine what substance can pass through the phospholipid layer

Answer 7

-polarity
-size
-charge
-lipid soluble
-concentration gradient
-transport proteins

Question 8

what type of solutes pass through the membrane easily

Answer 8

-small, non polar (O2, CO2, N)
- hydrophobic (steroids)
-water; through aquaporin channels

Question 9

which solutes pass through to a limited extent

Answer 9

• small polar (glucose)
  -charged ions (K*)
  -large polar (carbs and peptides)

Question 10

which solutes can not pass through at all

Answer 10

-large polar molecules (proteins and polysaccharides)
-ions and charged molecules (H+)
-drugs and toxins

Question 11

can a solute that is unable to cross the phospholipid bilayer freely enter the cell

Answer 11

yes, but with the help of transport proteins, active transport, and endocytosis

Question 12

what is the difference between a saturated fatty acid and an unsaturated fatty acid

Answer 12

unsaturated: kink in tails preventing tight packaging increases membrane permeability (think olive oil)
saturated: pack tingly together. membrane becomes less fluid, denser and less permeable

Question 13

in what way is the phospholipid bi-layer fluid

Answer 13

due to its ability to move molecules and shift within the inner membrane

Question 14

what other kind of lipids are present in the cell

Answer 14

cholesterol

Question 15

what is the effect of cholesterol on the membrane

Answer 15

cholesterol stops you from freezing and melting

Question 16

what determines how a substance diffuses

Answer 16

concentraiton gradient and available enrgy used for transport

Question 17

what is osmios

Answer 17

the movement of water from an area of high concentration to low concentration

Question 18

hypertonic, hypotonic, and isotonic

Answer 18

water moving out, water moving in, water moving in and out at the same rate.

Question 19

how are proteins arranged in the cell membrane

Answer 19

integral and peripheral

Question 21

what aspect allows proteins to be placed in hyrophci and hydrophilic area of the membrane

Answer 21

amphipathic