chapter 5

Question 1

what is osmotic equilibrium

Answer 1

free movement between cells and the ECF
- water is only molecule with free movement

Question 2

what is electrical disequilibrium

Answer 2

the inside of cells is negative relative to the outside

Question 3

what is chemical disequilibrium

Answer 3

major solutes in the body are more concentrated in one of the two body compartments

Question 4

how can the body be in osmotic equilibrium but electrical and chemical disequilibrium

Answer 4

osmotic equilibrium because water can move in and out of cells at a constant rate but the solutes in the body are still concentrated and and charged differently

Question 5

what is the distribution of water among compartments

Answer 5

• intracellular fluid volume: 2/3 of volume
• extracellular fluid volume: 1/3 of volume

Question 6

define and describe molarity

Answer 6

the number of moles of dissolves solute per liter (mol/L)

Question 7

define and describe osmolarity

Answer 7

concentration for biological solutions
- number of osmostically active particles (ions and molecules that can’t easily cross the cell membrane) per liter (osmol/L)

Question 8

define and describe osmotic pressure

Answer 8

pressure that must be applied to oppose osmosis
- not let concentrations be equal?

Question 9

define and describe tonicity

Answer 9

allows prediction of how solution will affect cell volume

Question 10

what is bulk flow

Answer 10

biological transport
- fluid and gas movement driven by pressure or temperature gradients

Question 11

describe solute movement across compartment membranes

Answer 11

membranes have selective permeability which can be specifically altered with membrane proteins

Question 12

compare bulk flow to solute movement across membranes

Answer 12

bulk flow is transport of fluid and gases due to pressure or gradients, while solute movement is when urea or gases can freely cross membranes and enter the cell

Question 13

describe simple diffusion

Answer 13

diffusion directly across phospholipid bilayer of membrane
- unaided diffusion

Question 14

describe vesicular transport

Answer 14

molecules that are too large for channels and carriers use vesicles
- bubble like formations made rom cell membrane

Question 15

describe diffusion in open system

Answer 15

molecules move from an area of higher concentration to area with lower concentration

Question 16

what are the seven properties diffusion follows

Answer 16

1. passive process
2. molecules move from high to low concentrations (chemical gradient)
3. net movement occurs until concentration is equal
4. rapid over short distances and slow over long distances
5. directly related to temperature
6. inversely related to molecule size (larger=slower)
7. occurs in open system or across partition between two separate systems

Question 17

describe movement on facilitated diffusion

Answer 17

molecule needs channel/transport protein to cross membrane

Question 18

describe active transport carriers

Answer 18

carriers on move one molecule or group of closely related molecule at a time

Question 19

compare movement through channels to movement on facilitated diffusion and active transport carriers

Question 20

define specificity

Answer 20

carriers only move one molecule or group of closely related molecules

Question 21

define competition

Answer 21

molecules with similar shape compete for binding sites on transporters and stop or slow down transport

Question 22

define saturation

Answer 22

rate of transport will increase as substrate concentration increases or until all carriers are full (transport maximum)

Question 23

describe trans cellular transport

Question 24

describe paracellular transport

Question 25

describe transcytosis

Answer 25

- plasma proteins are concentrated in caveolae then undergo endocytosis and for vesicles - vesicle cross cell - vessicle contents are released into ECF by exocytosis

Question 26

how do trans cellular transport, paracellular transport and transcytosis apply to epithelial transport

Answer 26

if molecule is too large so vesicular transport is used and energy is needed for movement across both membranes

Question 27

what is resting membrane potential

Answer 27

electrical gradient formed between ECF and ICF

Question 28

what does it mean for a cell to have resting membrane potential

Answer 28

when cells don't actively electrically signaling, electrical gradient reaches steady state, the steady state is RMP

Question 29

describe ion permeabiity

Answer 29

ability of ions to pass through membrane

Question 30

describe membrane potenial

Answer 30

electrical potential difference across cell membrane - uneven distribution of ions between ECF and ICF

Question 31

how do changes in ion permeability change membrane potential (give example)

Answer 31

membrane potential is determined by movement of ions across membrane. if one of the ions that is highly concentrated inside the cell flows outside it will make the inside of the cell more negatively charged

Question 32

what is the sequence of membrane transport-asscoiated steps that link increased blood glucose to insulin secretion from pancreatic beta cells

Answer 32

1. high glucose in blood 2. metabolism increases 3. ATP increases 4. Kate channels close 5. cell depolarizes and calcium channels open 6. Ca entry acts as an intracellular signal 7. Ca signal triggers exocytosis and insulin is secreted

Question 33

define homestasis

Answer 33

stability of the body internal environment

Question 34

are ICF and ECF same

Answer 34

no they are stable not the same they are at a dynamic disequilibrium

Question 35

define dynamic disequilibrium

Answer 35

maintain balance while in motion (things moving in and out)

Question 36

define osmosis

Answer 36

water moves from an area of lower solute concentration to higher solute concentration

Question 37

define semi-permeable

Answer 37

cells have membranes that allow water to move freely but solute movement is more restrictive

Question 38

what does it mean for solutions to be isosmotic what does it relate to

Answer 38

two solution with the same number of solute particles per volume - osmolarity

Question 39

what does it mean for a solution to be hyperosmotic what does it relate to

Answer 39

a solution with higher osmolarity

Question 40

what does it mean for a solution to be hypoosmotic and what does it relate to

Answer 40

solution with lower osmolarity

Question 41

what is hypotonic and what does it relate to

Answer 41

cell gains water after being placed in solution (water goes in cell) - tonicity

Question 42

what is hypertonic and what does it relate to

Answer 42

cell loses water - tonicity

Question 43

what is isotonic and what does it relate to

Answer 43

no change in cell volume (water goes in and leaves cell keeping it constant) - tonicity

Question 44

what are non-penetrating solutes

Answer 44

solutes unable to cross membrane freely (need specific transport) (ions, protein, glucose and lipids)

Question 44

what are penetrating solutes

Answer 44

solutes freely crossing membrane into cell (urea and gases) - doesn't impact water movement (achieves chemical equilibrium)

Question 45

what properties will dictate if a molecule can pass through a membrane

Answer 45

- size (small molecules pass through more freely) - lipid solubility (lipid soluble molecules can pass through) - water, O2 and Co2 can move freely

Question 46

what is used to facilitate transport through impermeable membranes

Answer 46

membrane proteins

Question 47

what is passive transport

Answer 47

uses potential energy stored in gradient to move molecules across membrane - with the gradient - uses simple and facilitated diffusion

Question 48

what is active transport

Answer 48

requires and input of energy from outside source to move molecule across membrane - against the gradient - uses primary and secondary active transport

Question 49

what are additional considerations for simple diffusion

Answer 49

rate of diffusion depends on nature of the molecule - molecular size - lipid content - water is exception - rate of diffusion is proportional to membrane surface area

Question 50

what is Fick's law of diffusion

Answer 50

rate of diffusion is proportional to: surface area x concentration gradient x membrane permeability

Question 51

what are the three types of vesicular transport

Answer 51

1. phagocytosis: import 2. endocytosis: import 3. exocytosis: export