Topic 2.8 - Tonicity and Osmoregulation 𖦹⋆｡°✩

Question 1

how does water move

Answer 1

by osmosis

Question 2

what is osmosis

Answer 2

the diffusion of free water across a selectively permeable membrane

Question 3

how do large quantities of water move

Answer 3

via aquaporins

Question 4

what is osmolarity

Answer 4

the total solute concentration in a solution

Question 5

does water have high solvency abilities

Answer 5

yes

Question 6

what is the difference between solutes and solvents

Answer 6

༻ a solute is the substance being dissolved
༻ a solvent is a substance that dissolves a solute

Question 7

what is a solution

Answer 7

a uniformed mixture of one more more solutes dissolved in a solvent

Question 8

solvent + solute = ?

Answer 8

solution

Question 9

what is tonicity

Answer 9

the measurement of the relative concentrations of solute between 2 solutions (inside and outside of the cell)

Question 10

what does tonicity affect

Answer 10

a cell’s physiology

Question 11

internal cellular environments can be ____, ____, or ____ to external environments

Answer 11

hypotonic (1) , hypertonic (2) , isotonic (3)

༻ (1) less solute, more solvent
༻ (2) more solute, less solvent
༻ (3) equal concentrations of solute and solvent

Question 12

where does water move by osmosis

Answer 12

water moves by osmosis into the area with a higher solute concentration

Question 13

what is the relationship between water and solute concentrations

Answer 13

they are inversely related

Question 14

how does water move in terms of tonicity

Answer 14

water diffuses out of a hypotonic environment into a hypertonic environment

Question 15

how do solutes diffuse

Answer 15

along their own concentration gradients, from the hypertonic environment to the hypotonic environment

Question 16

what happens when a cell is in an isotonic environment

Answer 16

a dynamic equilibrium exists with equal amounts of water moving in and out of the cell at equal rates. no net movement of water takes places

Question 17

what happens in some plant cells

Answer 17

osmoregulation maintains water balance and allows control of internal solute composition/water potential

Question 18

what is environmental hypertonicity

Answer 18

less cellular solute and more cellular water

Question 19

what is an isotonic solution

Answer 19

༻ equal solute and water
༻ flaccid

Question 20

what is environmental hypotonicity

Answer 20

༻ more cellular solute and less cellular water
༻ turgid

Question 21

how do osmoregulatory mechanisms contribute to survival

Answer 21

the cell wall helps maintain homeostasis for the plant in environmental hypotonicity

Question 22

when is osmotic pressure high outside of the plant cell

Answer 22

osmotic pressure high outside of the plant cell due to environmental hypotonicity

Question 23

what happens when water flows into the plant vacuoles via osmosis

Answer 23

the vacuoles expand and press against the cell wall. the cell wall expands until it begins to exert pressure back on the wall

Question 24

what is it called when the cell wall expands until it exerts pressure back on the cell

Answer 24

turgor pressure

Question 25

what is the optimum state for plant cells

Answer 25

turgidity

Question 26

how does osmoregulation impact animal cells

Answer 26

maintains water balance and allows control of internal solute composition/water potential

Question 27

what is environmental hypertonicity called in animal cells

Answer 27

shriveled

Question 28

what is an isotonic solution called in animal cells

Answer 28

normal

Question 29

what is environmental hypotonicity called in animal cells

Answer 29

lysed

Question 30

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Question 31

what does water potential measure and how is it calculated

Answer 31

the tendency of water to move by osmosis. it is calculated from pressure potential and solute potential

Question 32

what happens the more negative the water potential is

Answer 32

the more negative the water potential, the more likely water will move into the area

Question 33

when does water potential have a value of 0

Answer 33

water potential of pure water has a value of 0 in an open container

Question 34

what does osmoregulation allow organisms to control

Answer 34

༻ their internal solute composition ༻ water potential

Question 35

what will increasing the amount of solute in water cause

Answer 35

༻ an increase in solute potential ༻ a decrease in water potential

Question 36

what does increasing water potential cause

Answer 36

༻ an increase in pressure potential

Question 37

what does decreasing pressure potential will cause

Answer 37

༻ a decrease in water potential

Question 38

when does water potential equal the solute potential

Answer 38

in an open system (memorize formulae)

Question 39

what does the addition of solutes do to the solute potential

Answer 39

the addition of solutes is equal to a more negative solute potential