EXCITABLE TISSUES

Question 1

integral proteins

Answer 1

1. they have hydrophobic and hydrophilic region
2. span the membrane- allow passage of ions into and out of the cell.
3. carrier proteins or ion channels

Question 2

peripheral proteins

Answer 2

1. loosely bound to the surface of the cell membrane, either on integral protein or polar region of the bilipid layer.
2. function- cell adhesion and communication.
3. does not span the membrane.

Question 3

ion channels

Answer 3

1. made from integral proteins.

2. channels are either leaked or gated.

Question 4

leak channel

Answer 4

1. ion channel
2. always open
3. allow passage of Na, K, Ca, and Cl
4. ions move down their concentration gradient, from high to low.

Question 5

gated channel

Answer 5

1. ion channel

2. consists of, ligand-gated, mechanically gated, and voltage-gated.

Question 6

ligand-gated

Answer 6

1. gated channel
2. can be a chemical messenger
3. respond to the binding of a ligand to the integral protein that causes it to open.

Question 7

mechanically gated

Answer 7

1. gated channel

2. respond to vibration, stretch, and pressure

Question 8

voltage-gated

Answer 8

1. gated channel

2. open or close due to change in membrane potential.

Question 9

unassisted membrane transport

Answer 9

consists of :
1. simple diffusion
2. osmosis
allows small permeable molecules.

Question 10

assisted membrane transport

Answer 10

consists of :
1. facilitated diffusion
2. active transport
3. vesicular transport
impermeable molecules are assisted by integral proteins.

Question 11

simple diffusion

Answer 11

1. transport molecules down their concentration gradient and electrical gradient.
2. do not require ATP and carrier proteins.

Question 12

facilitated diffusion

Answer 12

1. requires carrier proteins or ion channels to transport ions down their concentration gradient and electrical gradient.
2. does not require ATP.

Question 13

active transport

Answer 13

1. requires carrier proteins or ion channels.
2. transport molecules against their concentration gradient.
3. requires ATP
4. there is primary and secondary active transport.

Question 14

primary active transport

Answer 14

1. NA, K pump
2. transport NA against its concentration gradient, from less to more
3. transport K against its concentration gradient, outside to inside

Question 15

secondary active transport

Answer 15

1. Na glucose symport transporter
2. moves Na down its concentration gradient in doing so it provides energy for glucose to move against its concentration gradient into the cell.

Question 16

vesicular transport

Answer 16

the active method of membrane transport

1. exocytosis
2. endocytosis

Question 17

membrane potential

Answer 17

the difference in charge across the plasma membrane

Question 18

potential is measured in

Answer 18

millivolts(Mv)

Question 19

where is sodium greater?

Answer 19

ECF

Question 20

where is Na greater?

Answer 20

ECF

Question 21

where is Cl greater?

Answer 21

ECF

Question 22

where is calcium greater?

Answer 22

ECF

Question 23

where are proteins greater?

Answer 23

ICF

Question 24

equilibrium potential

Answer 24

membrane potential at which ion influx and reflux are at electrochemical equilibrium.

Question 25

potassium equilibrium poteintial

Answer 25

1. concentration gradient moves K out of the cell, making the outside of the cell more positive.
2. cell membrane is impermeable to anions thus the inside becomes more negative.
3. electrical gradient is formed which moves K back into the cell.
4. no further movement of K, the membrane is at equilibrium.
5. the potential of K is -90 Mv

Question 26

sodium equilibrium potential

Answer 26

1. concentration gradient moves Na into the cell, making the inside more positive.
2. outside becomes unbalanced negative charge mostly Cl.
3. electrical gradient moves Na outside
4. no further movement of Na, the membrane is at equilibrium.
5. the potential is +60 Mv

Question 27

chloride potential equilibrium

Answer 27

-70 Mv

Question 28

resting membrane potential

the concentration gradient of ions

Answer 28

1. K diffuses outside the cell through leak channels

2. Na diffuses inside the cell through leak channels.

Question 29

resting membrane potential

permeability of the membrane to ions

Answer 29

1. small net diffusion of Na inward
2. large net diffusion of K outward
3. no net movement of Anions across the membrane.

Question 30

resting membrane potential

the activity of Na K ATPase pump

Answer 30

1. moves 3 Na out and 2 K in

2. maintains the concentration gradient