Exam One - 1.5 Membrane Dynamics

Question 1

What contributes to homeostatic dynamic disequilibrum?

Answer 1

• two fluid compartments (ICF and ECF)
• osmotic equilibrium
• chemical disequilibrium
• electrical disequilibrium

Question 2

Explain water content differences between sex and age

Answer 2

• no difference as kids between sex
• during puberty men have more water
• males have more water at older ages
  different because of test levels

Question 3

osmosis

Answer 3

movement of water across a membrane

Question 4

osmotic pressure

Answer 4

the pressure that must be applied to oppose osmosis

Question 5

Molarity

Answer 5

expresses concentration

Question 6

Osmolarity

Answer 6

expresses number of osmotically active particles

the concentration of a solution expressed as the total number of solute particles per liter

Question 7

Is molarity or osmolarity more relevant for physiology?

Answer 7

osmolarity

Question 8

osmolality

Answer 8

the concentration of a solution expressed as the total number of solute particles per kilogram

Question 9

t or f? isosmotic is not always isotonic

Answer 9

true

Question 10

t or f? hyperosmotic is not always hypertonic

Answer 10

true

Question 11

t or f? hyposmotic is always hypotonic

Answer 11

true

Question 12

isosmotic

Answer 12

equal osmotic pressure, equal solutes
cell size doesnt change

Question 13

hyperosmotic

Answer 13

more solutes
cells shrink

Question 14

hyposmotic

Answer 14

less solutes
cells swell

Question 15

tonicity describes…

Answer 15

volume change of cells

Question 16

tonicity depends on…

Answer 16

the concentration of the nonpenetrating solutes

Question 17

osmolarity (osmol/liter) =

Answer 17

molarity (M, moles/liter) x particles/molecule (osmol/M)

Question 18

4 different transport processes

Answer 18

diffusion
protein-mediated transport
vesicular transport
epithelial transport

Question 19

Diffusion (7)

Answer 19

1 - passive process
2 - high concentration to low concentration
3 - net movement until concentration is equal
4 - rapid over short distances
5 - directly related to temperature
6 - inversely related to molecular weight and size
7 - open system or across a partition

Question 20

Simple diffusion of lipophilic molecules have two extra properties…

Answer 20

rate depends on solubility in lipids
proportional to surface area of the membrane

Question 21

electrochemical gradient

Answer 21

ion movement combination of concentration (chemical) gradient and electrochemical gradient

Question 22

4 major functions of membrane proteins

Answer 22

1 - structural proteins
2 - membrane enzymes
3 - membrane receptor proteins
4 - transport proteins (channel and carrier proteins)

Question 23

4 types of open, water-filled channel proteins

Answer 23

1 - water channels
2 - ion channels
3 - open channels (leak and pores)
4 - gated channel (chemically, voltage, and mechanically gated channels)

Question 24

2 types of protein - mediated transport

Answer 24

facilitated diffusion
carrier transport

Question 25

3 types of carrier transport

Answer 25

symport - carries 2 things at once same direction antiport - carries 2 things at once in opposite directions uniport - only carries one thing

Question 26

Does active transport move substances with or against concentration gradients?

Answer 26

Against

Question 27

2 types of energy active transport can use:

Answer 27

Primary (direct) - use ATP Secondary (indirect) - uses potential energy stored in concentration gradients of one molecule to push another against its gradient

Question 28

sodium potassium pump

Answer 28

antiporter active transport use ATP energy

Question 29

sodium glucose cotransporter

Answer 29

uses concentration gradient for potential energy Na goes with gradient Glucose against gradient

Question 30

transport rate is proportional to _________ until the carriers are _____________

Answer 30

substrate concentration, saturated

Question 31

phagocytosis

Answer 31

eats bad stuff

Question 32

2 kinds of endocytosis

Answer 32

clathrin - mediated caveolae - mediated

Question 33

clathrin - mediated

Answer 33

enters cell and most often ends up in lysosome

Question 34

caveolae - mediated

Answer 34

enters cell and gets used by ER to make stuff

Question 35

Exocytosis releases molecules ______________ for transport proteins or for large volumes

Answer 35

too large

Question 36

transporting epithelia are __________

Answer 36

polarized

Question 37

explain transepithelial absorption of glucose

Answer 37

1 - Na and glucose symporter. Na is going from high to low, glucose is going from low to high 2 - glute transporter - now going from high in the cell to low in ECF 3 - NaK ATPase NA going from low to high(ECF) and K going into cell

Question 38

transcytosis

Answer 38

vesicles cross an epithelium requires energy keeps transported materials intact

Question 39

body is electrically _______

Answer 39

neutral

Question 40

chemical disequilibrium between?

Answer 40

ICF and ECF

Question 41

ICF has a net ________ charge

Answer 41

negative

Question 42

ECF has a net ___________ charge

Answer 42

positive

Question 43

Explain why K wants to leave cell due to concentration gradient but enter cell due to electrical gradient

Answer 43

there is more K inside cell than outside therefore it wants to leave due to concentration gradient K is positive and the inside of the cell is negative. The positive charge outside the cell repels K because K is also slightly positive

Question 44

Potential energy of the membrane is stored in the ?

Answer 44

electrochemical gradient

Question 45

What is the resting membrane potential of cell?

Answer 45

about -70mV

Question 46

depolarization

Answer 46

shift in electric charge distribution, resulting in less negative charge inside cell

Question 47

repolarization

Answer 47

change in membrane potential that returns it to a negative value just after the depolarization phase of an action potential has changed the membrane potential to a less negative (mroe positive) value

Question 48

hyperpolarization

Answer 48

change in a cell's membrane potential that makes it more negative

Question 49

Insulin secretion and membrane transport if there are low glucose levels in the blood:

Answer 49

1 - low glucose levels in blood 2 - metabolism slows 3 - ATP decreases 4 - KATP channels open and K leaks out of cell 5 - cell at resting membrane potential (Ca+ channels closed) and no insulin is released

Question 50

Insulin secretion and membrane transport if there are high levels of glucose in the blood:

Answer 50

1 - high levels of glucose in blood 2 - metabolism increases (glycolysis and CAC) 3 - ATP increases 4 - KATP channels close and K doesn't leak out 5 - cell depolarizes and Ca+ channels open 6 - Ca+ entry acts as an intracellular signal 7 - Ca+ signal triggers exocytosis and insulin is released