Lecture 10

Question 1

What is the function of transport proteins

Answer 1

• Speed the passive movement of molecules across the plasma membrane
• provide corridors for specific molecules or ions into or out of the cell

Question 2

What’s a channel protein

Answer 2

Protein that provides hydrophilic corridors

Question 3

What is a carrier protein?

Answer 3

• undergo change in shape

- translocates the solute- binding site across the membrane

Question 4

What is osmosis?

Answer 4

Lateral movement of phospholipids allows for a some diffusion across plasma membrane

Question 5

What are aquaporins?

Answer 5

Channel proteins for facilitated diffusion of water, tissue specific

Question 6

What is a hypotonic solution? Hypertonic solution

Answer 6

Hypo- take in too much water and Burst

Hyper- doesn’t take in enough water and shrivels

Question 7

When a cell is turgid it is? What about plasmolysis? Flaccid?

Answer 7

Plasmolyzed- loses water, shrivels and pulls away from cell wall
Flaccid- water in and out at equal rate
Turgid - gains water, cell wall resists pressure

Question 8

How much Waterford starch and glycogen need as solvent

Answer 8

Very little

Question 9

What’s the difference between passive transport and active transport

Answer 9

Passive is with concentration gradient and releases nrg and active transport goes against the concentration gradient and requires nrg input

Question 10

What is the Na-K pump

Answer 10

• a protein that pumps sodium and potassium in and out of a cell
• has binding signs specific for each ion
• binding and releasing of ions and phosphate changes shape of pump protein

Question 11

Why do animal cells maintain in relation to sodium and potassium

Answer 11

Higher concentration of potassium and lower concentration of sodium inside vs. Outside the cell

Question 12

How does a sodium potassium pump work?

Answer 12

• 3 sodium from the cytoplasm binds to the proteins
• sodium stimulates phosphorylation by ATP
• above causes protein to change shape expelling the sodium
• 2 potassium binds to the pump which causes the phosphate group to leave
• loss of phosphate causes protein to go to original shape and expel potassium into the cell

Question 13

How do animal cells that have to for a barrier to prevent breakage hold together? (Skin cells)

Answer 13

Bound tightly together by proteins -right junktions

Question 14

How do cells that have to resist forces hold them self’s together? (Muscle)

Answer 14

Intermediate filaments holding cells together in strong sheets

Question 15

How do cells that need o communicate with each other hold together? (Heart cells)

Answer 15

Gap junctions

Question 16

what is tonicity

Answer 16

Relative total solute concentration difference that can lead to osmosis

Question 17

What is isotonic?

Answer 17

Equal concentrations of diluted across a membrane, no net movement of water

Question 18

What’s the difference between hypertonic and hypotonic

Answer 18

Hypertonic is an area/solution of higher tonicity (more total solutes) hypotonic is lower tonicity (less total solutes)

Question 19

What is osmosis?

Answer 19

Water diffuses from a hypertonic solution to a hypotonic solution