Bio Chapter 5

Question 1

What does it mean for phospholipids to be amphipathic molecules?

Answer 1

The tail is hydrophobic - fears water, 2 fatty acid chains that are nonpolar
The head is hydrophilic - loves water, glycerol molecule and a phosphate group that is polar

Question 2

Phospholipids - saturated and unsaturated

Answer 2

Carbons are saturated with H, only single bond
Carbons are unsaturated when at least on C=C double bond is present

Question 3

Phospholipids

Answer 3

Most abundant lipid in plasma membrane
Will automatically arrange themselves in a bilayer with the polar heads facing outward and the hydrophobic tails are inward

Question 4

Permeability of lipid bilayer

Answer 4

Controlled by the plasma membrane
Hydrophobic molecules can dissolve in lipid bilayer and pass through membrane rapidly
Hydrophilic molecules do not cross membrane easily

Question 5

Diffusion

Answer 5

Tendency for molecules to spread out evenly

Question 6

Passive transport

Answer 6

Movement across a membrane with no energy investment

Question 7

Diffusion vs. Osmosis

Answer 7

Diffusion is small uncharged molecules (O2 and CO2)
Osmosis is the diffusion of water

Question 8

Osmosis

Answer 8

Diffusion of water across selectively permeable membrane
From a region of lower solute concentration to higher solute concentration

Question 9

Hypotonic

Answer 9

Concentration outside cell is less than inside

Question 10

Hypertonic

Answer 10

Concentration outside cell is greater than inside

Question 11

Isotonic

Answer 11

Concentration is same inside and outside cell

Question 12

Active transport

Answer 12

Uses energy to move solutes against their gradients

Question 13

Primary active transport

Answer 13

ATP provides energy

Question 14

Secondary active transport

Answer 14

Electrochemical gradient provides energy

Question 15

Membrane potential

Answer 15

Voltage across a membrane
Cytoplasmic side carries negative charge compared to extracellular side

Question 16

Sodium potassium pump

Answer 16

Move in opposite directions
If they bring 3 in then 2 must go out
Uses energy from ATP hydrolysis

Question 17

ATP

Answer 17

3 phosphate

Question 18

ADP

Answer 18

2 phosphates

Question 19

AMP

Answer 19

1 phosphate

Question 20

Endocytosis

Answer 20

Cells takes in macromolecules

Question 21

Pinocytosis

Answer 21

Soluble materials are taken up from environment and incorporated into vesicles for digestion (little sips)

Question 22

Phagocytosis

Answer 22

Uptake of larger particles
Once engulfed, turns into phagosome, then fuses with lysosome to break down contents

Question 23

Exocytosis

Answer 23

Releasing through vesicle outside the cell

Question 24

Receptor mediated endocytosis

Answer 24

Receptor in membrane that mediates process of endocytosis
Specific solutes bind to receptors triggering vesicle formation