CH. 6 - Transport

Question 1

Extracellular Environment

Answer 1

Includes all constituents of body outside cells

Question 2

67% of total body H2O is inside cells

Hint: inside

Answer 2

intracellular compartment

Question 3

33% H2O is outside cells

Answer 3

extracellular compartment-ECF

Question 4

80% of ECF….

Answer 4

is interstitial fluid

Question 5

Extracellular Matrix

Answer 5

meshwork of collagen and elastin fibers linked to molecules of gel-like ground substance and to plasma membrane integrins

Question 6

integrins

Answer 6

glycoprotein adhesion molecules that link intracellular and extracellular compartments

Question 7

Plasma membrane is _____ (Hint: allows certain molecules to pass)

Answer 7

Selectively permeable

Question 8

Carrier-mediated transport invloves what?

Answer 8

involves specific protein transporters

Question 9

Non-carrier mediated transport occurs by….

Answer 9

occurs by diffusion

Question 10

moves compounds down concentration gradient; requires no energy

Answer 10

Passive transport

Question 11

moves compounds against a concentration gradient; requires energy and transporters

Answer 11

Active transport

Question 12

random motion of molecules

Answer 12

Diffusion

Question 13

________compounds readily diffuse thru cell membrane. As well as CO2 and H2O

Answer 13

Non-polar

Question 14

Cell membranes are ______ to _______ and most polar compounds

Answer 14

impermeable, charged

Question 15

How do charged molecules move across membrane?

Answer 15

Through an ion channel or transporter

Question 16

Rate of diffusion depends on…

Answer 16

Temp., surface area, permeability of membrane, magnitude of concentration gradient

Question 17

net diffusion of H2O across a selectively permeable membrane

Answer 17

Osmosis

Question 18

H2O diffuses ______ its concentration gradient

Answer 18

Down

Question 19

H2O is less concentrated where there are more ______

Answer 19

solutes

Question 20

Solutes have to be _______ (Hint: cannot move freely across membrane)

Answer 20

osmotically active

Question 21

water channels are called _____

Answer 21

Aquaporins

Question 22

Osmotic Pressure

Answer 22

the force that would have to be exerted to stop osmosis

Question 23

Proportional to solute conc.

Answer 23

Osmotic pressure

Question 24

M = mol/L

Answer 24

Molarity

Question 25

m = mol solute/kg solvent

Answer 25

Molality

Question 26

Osmolality

Answer 26

total molality of a solution

Question 27

Tonicity

Answer 27

Is the effect of a solution on osmotic movement of H2O

Question 28

Isotonic

Answer 28

solutions have same osmotic pressure

Question 29

Hypertonic

Answer 29

solutions have higher osmotic pressure and are osmotically active

Question 30

Hypotonics

Answer 30

have lower osmotic pressure

Question 31

Isosmotic

Answer 31

solutions have same osmolality as plasma

Question 32

Hypo-osmotic

Answer 32

solutions have lower osmotic pressure than plasma

Question 33

Hyperosmotics

Answer 33

have higher pressure than plasma

Question 34

Blood osmolality is maintained in narrow range around ________

Answer 34

300mOsm

Question 35

If dehydration occurs, osmoreceptors in hypothalamus stimulate:

Answer 35

ADH release, Which causes kidney to conserve H2O and thirst

Question 36

Protein carriers exhibit...

Answer 36

Specificity, Competition, Saturation

Question 37

Facilitated Diffusion

Answer 37

passive transport down concentration gradient by carrier proteins

Question 38

Active Transport Pump

Answer 38

transport of molecules against a concentration gradient

Question 39

What is required for Active Transport?

Answer 39

ATP and carrier protein

Question 40

Uses ATP to move 3 Na+ out and 2 K+ in, Against their gradients

Answer 40

Na+/K+ Pump

Question 40

transport of Na+ into cell

Answer 40

Secondary Active Transport

Question 40

Cotransport (symport)

Answer 40

secondary transport in same direction as Na+

Question 40

Countertransport (antiport)

Answer 40

moves molecule in opposite direction to Na+

Question 41

Absorption

Answer 41

transport of digestion products across intestinal epithelium into blood

Question 41

Reabsorption

Answer 41

transports compounds out of urinary filtrate back into blood

Question 41

Occurs by endocytosis and exocytosis (Hint: Large molecules)

Answer 41

Bulk Transport

Question 41

moves material from 1 side to other of epithelial cells

Answer 41

Transcellular transport

Question 41

Transport between cells is limited by ________ that connect adjacent epithelial cells

Answer 41

junctional complexes

Question 41

Paracellular transport

Answer 41

moves material through tiny spaces between epithelial cells

Question 41

proteins “button” two membranes together

Answer 41

desmosomes

Question 42

difference in charge across membranes

Answer 42

Membrane Potential

Question 43

Describes voltage across cell membrane if only 1 ion could diffuse (same inside as outside)

Answer 43

Equilibrium Potential

Question 44

membrane voltage of cell not producing impulses

Answer 44

Resting Membrane Potential (RMP)

Question 45

k+ is most _____

Answer 45

Permeable

Question 46

RMP of most cells is...

Answer 46

–65 to –85 mV

Question 47

Because 3 Na+ are pumped out for every 2 K+ taken in, pump is ______

Answer 47

electrogenic

Question 48

gap junctions

Answer 48

How cells communicate, signals pass directly from one cell to the next

Question 49

a target cell must have a ______ to respond to a chemical signal

Answer 49

receptor protein

Question 50

paracrine signaling

Answer 50

cells secrete regulatory molecules that diffuse to nearby target cells

Question 51

1 neuron sends neurotransmitter messages to another cell via SYNAPSES

Answer 51

synaptic signaling

Question 52

endocrine signaling

Answer 52

cells secrete chemical regulators that move thru blood stream to distant target cells

Question 53

How Regulatory Molecules Influence Target Cells,

Answer 53

Nonpolar regulatory molecules pass through plasma membrane, bind to receptors in nucleus, and affect transcription. EX: steroid and thryroid hormones and nitric oxide Polar regulatory molecules bind to cell surface receptors

Question 54

Second Messengers

Answer 54

May be ions (e.g. Ca++) or other molecules such as cyclic AMP (cAMP) or G-proteins

Question 55

Contain 3 subunits whose components dissociate when a cell surface receptor is activated

Answer 55

G-proteins