Water

Question 1

what is water helpful for

Answer 1

transpirational cooling
photosynthesis
transport
turgor

Question 2

what is it about H bonds and polarity of water that connects to thermal and physical properties

Answer 2

water can make H bonds which are much weaker than covialent bonds. there is an attraction between partial + and partial - charge on neighbor molecule. This means it can bond to any molecule with a charge. Polarity is responsible for soil and xylem flow because it allows water to connect to other surfaces and molecules too.

Question 3

3 properties of water

Answer 3

high specific heat
solvent
cohesion and adhesion

Question 4

High specific heat

Answer 4

it takes a lot of energy to change water temp by one degree

Question 5

high thermal conductivity

Answer 5

plant can conduct heat away from site where the heat is generated ( cool down)

Question 6

how does water absorbing and dissipating heat benefit the plant

Answer 6

good bulk flow- make or break H bonds

Question 7

what about water makes it a good solvent

Answer 7

polarity

Question 8

definition of ionic substance

Answer 8

charged

Question 9

cohesion

Answer 9

water attracted to eachother via hydrogen bonds

Question 10

what is stronger- cohesion or adhesion

Answer 10

cohesion

Question 11

adhesion

Answer 11

attraction of water to soild surfaces

Question 12

capillarity

Answer 12

cohesion and adhesion

Question 13

what is smaller in phloem, tracheid’s or veins

Answer 13

tracheids

Question 14

if cohesion is greater than adhesion what happens

Answer 14

water droplets

Question 15

soil water repellancy

Answer 15

uneven wetting front- water puddles on dry dirt

Question 16

why does soil water repellancy happen

Answer 16

organic matter is hydrophobic- you must apply a wetting agent for soil to be wet again

Question 17

what are surfactants

Answer 17

aids in soil water repellency

Question 18

what can cause hydrophobicity in soil

Answer 18

dead plant material - high net carbon creates parches that are hydrophobic. Also mycelium and roots secreting their substances.

Question 19

does the transport of water occur actively or passively with bulk flow and diffusion

Answer 19

passively

Question 20

bulk flow

Answer 20

Driven by pressure , transpiration, and gravity in plants

Question 21

diffusion

Answer 21

direct movement of a substance from high concentration to low concentration

Question 22

osmosis

Answer 22

diffusion of water across a selectively permeable membrane

Question 23

what protein moves water in bulk

Answer 23

channel protiens

Question 24

water moves from ___ free water to _____ free water

(More or less)

Answer 24

more free water to less free water

Question 25

what is free water

Answer 25

water not attached to a solute (solute makes hydration shells around sugars)

Question 26

TF selectively permeable membrane allows water to pass through but not solutes

Answer 26

T

Question 27

The passive movement of water across a membrane is a combination of ___________ and __________- __________

Answer 27

diffusion and bulk flow

Question 28

aquaporin

Answer 28

protein that allows water to pass through the membrane

Question 29

water movement depends on a difference in ___________ of water in two parts of a system

Answer 29

chemical energy

Question 30

water will move passively from ___ to _____ chemical potential

Answer 30

higher to lower

Question 31

TF water moves passively and actively

Answer 31

F it only moves passively

Question 32

how do plants control water movement

Answer 32

controlling solutes

Question 33

is water potential positive

Answer 33

no it's always negative

Question 34

osmotic potential

Answer 34

change in free energy of water from dissolved solutes

Question 35

what is pure waters solute potential

Answer 35

0

Question 36

hypertonic

Answer 36

high solutes

Question 37

hypotonic

Answer 37

low solutes

Question 38

the more negative the water potential is, the (more/less) free water in the cell

Answer 38

LESS

Question 39

turgor pressure

Answer 39

pressure potential in plants can be postive or negative

Question 40

positive turgor pressure is in

Answer 40

insidde cells

Question 41

negative turgor pressure is in

Answer 41

xylem

Question 42

what organelle has the greatest influence on water potential and turgor pressure

Answer 42

vacuole

Question 43

water potential gradients tell which direction water will move TF

Answer 43

T

Question 44

osmotic adjustment

Answer 44

plants adjust their cell solute content to respond to drought

Question 45

what is the mPa of saturation

Answer 45

0 MPA

Question 46

What is field capacity

Answer 46

the amount of water the soil can hold against gravity

Question 47

What is the mPa of the wilting point

Answer 47

-1.5 MPa

Question 48

if the plants mPa is -1,5 mPa and the soils mPa is -0.01 then will water go in or out of the plant

Answer 48

in

Question 49

air is typically -50 mPa. Will water normally go in or out of plant from air

Answer 49

out of plant into air

Question 50

radial conductance what affects it

Answer 50

anatomy, cell wall permeability, activity of water channels

Question 51

axial conductance

Answer 51

happens through xylem

Question 52

what are the two ways that water can take axially

Answer 52

symplastically and apoplatistically

Question 53

simplistically

Answer 53

water moving through the root through the cells (slower)

Question 54

apoplastic movement of water

Answer 54

movement through cell walls of water. faster, but then the water must move symplastically through the endodermis

Question 55

Casparian strip

Answer 55

Suberin filled strip that keeps water in the endodermis

Question 56

what are the 2 points of resistance that water can hit when water moves into moves

Answer 56

1. water moving vis apoplasticallt vs symplastically 2. Casparian band

Question 57

root traits affecting water uptake

Answer 57

hydraulic conductivity total root mass root length root hair abundance spatial distribution

Question 58

when is it advantageous to have long roots (nutrients)

Answer 58

nitrogen deficient areas phosphorous stays on the surface

Question 59

what are the two cell types of xylem

Answer 59

tracheids and vessels hollowed, thickened, conducting cells

Question 60

tracheids

Answer 60

gymosperm narrow

Question 61

vessels

Answer 61

angiosperm wide and short

Question 62

what moves water faster, traacheids or vessels

Answer 62

vessels

Question 63

capillary rise is inversely proportional to _____ and ________radius

Answer 63

tracheid and vessel

Question 64

transpiration

Answer 64

flow of water from leaf to air

Question 65

what is the major mechanism for long distance

Answer 65

transpiration

Question 66

elements to water flow in leaves

Answer 66

veins -> mesophyll -> stomata -> air

Question 67

what is the driving force for transpiration

Answer 67

differences in concentration of water vapor between leaf air spaces and the atmospheere

Question 68

what factors impact transpiration

Answer 68

stomata, cuticle, mesophyll, boundary layer, temperature, vapor pressure gradient, environmental factors (transpiration)

Question 69

what is the most important leaf specific factor that impacts transpiration

Answer 69

stomatal resistance (whether they're open or closed)

Question 70

mesophyll resistance

Answer 70

the less compact the mesophyll is in a lead, the less a chance the water has to get to the guard cell

Question 71

what is the mesophyll

Answer 71

inner cells of a plant

Question 72

cuticle resistance to water

Answer 72

epidermal cells are surrounded with a cuticle to prevent water loss

Question 73

boundary layer

Answer 73

area outside of epidermal cells the calm air that surrounds the exterior of the leaf

Question 74

the boundary layer impacts how quickly the plant absorbs ___ and exports ___-

Answer 74

CO2 and O2

Question 75

a thick boundary layer increases or decreases water vapor exititng

Answer 75

decreases because the relative humidity around a plant leaf is increased

Question 76

does a thick boundary layer increase water loss

Answer 76

no it decreases it

Question 77

does a thick boundary layer increase a plants ability to cool itself

Answer 77

no , it decreases it bc less transpiration

Question 78

does a thick boundary layer decrease the amt of nutrients

Answer 78

yes

Question 79

what impacts the boundary layer

Answer 79

leaf hairs wind leaf shape

Question 80

environmental factors that affect transpiration

Answer 80

temperature relative humidity wind solar radiation water availability

Question 81

how does temp impact transpiration

Answer 81

increases transpiration and kinetic energy of molecules

Question 82

how does relative humidity affect transpiration

Answer 82

lowers transpiration rate and moves free water outside to increase the vapor pressure gradient

Question 83

when is low humidity good in plants

Answer 83

flowering - less chance for diseases

Question 84

what is high humidity good for

Answer 84

germination, grafting, and early propagation cuttings

Question 85

how does wind affect the boundary layer

Answer 85

dissolves it