Homeostasis and Transport

Question 1

Na+ extracellular fluid

Answer 1

142 mEq/L

Question 2

Na+ intracellular fluid

Answer 2

10 mEq/lL

Question 3

K+ extracellular fluid

Answer 3

4 mEq/L

Question 4

K+ intracellular fluid

Answer 4

140 mEq/L

Question 5

Cl- extracellular fluid

Answer 5

103 mEq/L

Question 6

Cl- intracellular fluid

Answer 6

4 mEq/L

Question 7

does not require energy and may require a channel protein or a carrier protein

Answer 7

Diffusion (passive transport)

Question 8

factors that alter diffusion rate

Answer 8

membrane permeability
concentration difference (chemical force)
electrical potential (chemical force)
pressure

Question 9

simple diffusion has which 2 types of channels

Answer 9

voltage gated and ligand gated

Question 10

Voltage channel Na+ channels has which gates

Answer 10

TWO GATES
Resting -70 mV
activation: channel depolarized to -55-+35 mV to allow Na+ to enter the cell
inactivation: inside channel closes from +35 to -70 mV to stop Na+ from entering the cell

Question 11

Voltage gated K+ channels has which gates

Answer 11

ONE gate
Resting: -70 mV
Slow activation: membrane depolarizes to +35 to -70 mV to allow K+ to leave the cell
(Na+ channels remain closed)

Question 12

receptor operated ion channel that induces a conformational change

Answer 12

Ligand-gated receptor channel

• acetylcholine bind a receptor on the cell membrane and induces a conformational change and ions can then go through the channel
• sodium and potassium can go through the same channels
• ligan gated G-protein coupled ion channels

Question 13

facilitated diffusion

Answer 13

• moves from area of high concentration to low concentration

- requires a transport protein to induce a conformational change to enter through the channel

Question 14

how is facilitated diffusion determined?

Answer 14

Vmax-maximum rate of diffusion

-concentration and rate of movement of carrier molecules across the channel

Question 15

movement of molecules against the concentration gradient. Requires energy & carrier protein

Answer 15

active transport

Question 16

what is the source of energy in primary active transport

Answer 16

ATP
EX. Na+/K+ pump
Ca++ pump
H+ pump

Question 17

uses energy of one solute moving with the concentration gradient (created previously with primary active transport) to move another substance against the concentration gradient

Answer 17

secondary active transport

Question 18

both ions move in the same direction

Answer 18

cotransporters (symport)

Ex. Glucose and Na+ entering cell in secondary active transport

Question 19

both ions move in different directions

Answer 19

exchangers (antiport)

Ex. K+ and Na+ in primary active transport- uses ATP

Question 20

uses a gradient of one molecule to move another against the concentration gradient but in opposite directions

Answer 20

exchangers or antiport (counter-transport)

Question 21

solvent moving from an area of high solvent concentration to an area of low solvent concentration across a semi-permeable membrane

Answer 21

osmosis

Question 22

pressure required to maintain an equilibrium with no net movement of solvent

Answer 22

osmotic pressure

Question 23

• water can move; ions cannot

- movement determined by molar concentration of solute

Answer 23

semi-permeable membrane

Question 24

moles of solute per liter of solution

Answer 24

molarity

Question 25

osmoles of solute per liter of solution

Answer 25

osmolarity

Question 26

the minimum pressure which needs to be applied to a solution to prevent the inward flow of its pure solvent across a semipermeable membrane

Answer 26

osmotic pressure

Question 27

how is osmotic pressure determined?

Answer 27

by the NUMBER of particles; not the size

Question 28

what happens when a cell is placed in a hypertonic solution?

Answer 28

water will rush out of the cell - the solution has a greater solute concentration (hyper osmotic) compared to the inside of the cell - cell is shriveled - move from low solute inside the cell to high solute outside the cell

Question 29

what happens when a cell is placed in a hypotonic solution?

Answer 29

water will rush into the cell - the solution has a lesser solute concentration (hypo osmotic) compared to the inside of the cell - cell is lysed - high solute outside the cell and low solute inside the cell

Question 30

a solution that has the same solute concentration as the inside of the cell

Answer 30

isotonic solution | -normal cell

Question 31

1 M of glucose has how many osmoles or particles?

Answer 31

one

Question 32

1 M of NaCl has how many osmoles or particles?

Answer 32

two

Question 33

1 M of CaCl2 has how many osmoles or particles?

Answer 33

three

Question 34

what is the normal osmolality inside and outside the cell for an isotonic solution?

Answer 34

280-310 mOsm/L

Question 35

in a normal cell of the body, intracellular concentrations of sodium, calcium, and chloride are ___ than extracellular concentrations

Answer 35

less

Question 36

potassium has a __ intracellular concentration compared to its extracellular concentration

Answer 36

higher

Question 37

what is not rate limited by Vmax?

Answer 37

simple diffusion- linear

Question 38

Ouabain-sensitive transport of Na+ ions from the cyto- sol to the extracellular fluid is what kind of transport?

Answer 38

Primary active transport - Ouabain inhibits Na+, K+, ATPase. - ATP dependent enzyme that transports 3 Na+ out of the cell for every 2 K+ enzymes into the cell

Question 39

glucose uptake into skeletal muscle is what kind of transport?

Answer 39

Facilitated diffusion | -insulin dependent

Question 40

Na+-dependent transport of Ca++ from the cytosol to the extracellular fluid is what kind of transport?

Answer 40

Counter-transport | -aka secondary active transport

Question 41

Movement of Na+ ions into a nerve cell during the up- stroke of an action potential is what kind of transport?

Answer 41

Simple diffusion -During the rapid depolarization phase of a nerve action potential, voltage-sensitive Na+ channels open and allow the influx of Na+ ions into the cytosol. Trans- port through membrane channels is an example of simple diffusion.

Question 42

moves fluid and gases

Answer 42

circulation

Question 43

fluid to interstitial space and into and out of cells; gas from extracellular fluid and into and out of cells; ions and molecules from high to low concentration gradient

Answer 43

diffusion

Question 44

movement of ions/ molecules through channels or transporters into and out of cell; pumping of molecules against a concentration gradient;

Answer 44

transport | - includes both passive and active

Question 45

a physiological change leads to an even greater change in the same direction

Answer 45

positive feedback

Question 46

the body senses a change and activates mechanisms to reverse that change

Answer 46

negative feedback

Question 47

what is the charge outside the cell? | inside the cell?

Answer 47

outside the cell has more positive charges | inside the cell has more negative charges