ORGANISM ADAPTATIONS: MOISTURE
adventitious root
- root which arises in positions where roots normally would not grow - replace the function of the original roots where oxygen is available - Plant response to too much water
give the starting reaction of photorespiration
- rubisco acts on oxygen instead of carbon dioxide. - oxygen fixing reaction
succulency
- store water in cells structure - vacuoles
define photolysis and explain when and where it occurs in the process of photosynthesis
- the splitting or decomposition of a chemical compound by means of light energy or photons - split water molecule
describe the urine of a well hydrated ostrich vs a dehydrated ostrich
- thick paste - goblet cell produce mucus - non permanent/ non fatal
explain the relationship between turgor pressure and water potential
- total water potential (Ψtotal) is lower outside the cells than inside, water moves out of the cells and the plant wilts. When - total water potential is higher outside the plant cells than inside, water moves into the cells, resulting in turgor pressure (Ψp), keeping the plant erec
explain how dormancy helps plants maintain the proper water balance
- underground storage (rhizome/bulb/tubular) - rain lily - not actively growing - perennials/non herbaceous
metabolic water
- water created inside a living organism through their metabolism, by oxidizing energy-containing substances in their food - water produced as an end product of the oxidation of energy-containing molecules such as carbohydrates, fats and proteins
explain how tenebrionid beetles obtain water on sand dunes by standing on their head
- water drops from sand - moisture collects on abdomen - tilt abdomen upward to collect H2O
how much water is typically lost by a dehydrated ostrich daily?
0.5 kg
give the optimum temperature for growth for C3 plants
18C-24C
how much water is typically lost by a well hydrated ostrich daily?
2.5 kg
what is the typical rate of photorespiration in C3 plants?
25-50%
what percentage of terrestrial plants are C4 plants?
3%
give the optimum temperature for growth for C4 plants
30-50C
over a seven-day period of water deprivation the ostrich urine osmolarity changes by what percentage?
380%
over a seven-day period of water deprivation the ostrich blood plasma osmolarity changes by what percentage?
61%
write the equation for photosynthesis
6CO2 + 6H2O + light energy --> C6H12O6 + 6O2 - converting light energy to chemical energy and storing it in the bonds of sugar
what percentage of water is saved by an ostrich that concentrates its urine?
80%
solute
A substance that is dissolved in a solution.
list the energy sources of the Calvin cycle
Adenosine triphosphate (ATP) Nicotinamide adenine dinucleotide phosphate hydrogen (NADPH)
which adaptation of plants to too much water is analogous to a snorkel?
Aerenchyma - interconnected gas filled chambers throughout the plant
how do higher temperatures affect photorespiration?
As leaf temperatures increase, photorespiration rates rise faster than do photosynthetic rates
photosynthesis
Biochemical process of converting light energy to chemical energy and storing it in the bonds of sugar 6CO2 + 6H2O (+ light energy) -> C6H12O6 + 6O2 Two part process: - Light reactions - light dependent - Dark reactions - light independent
what do GAP, PGAL, and G3P stand for?
Glyceraldehyde 3-phosphate the product of the Calvin cycle 3-carbon sugar that is the starting point for the synthesis of other carbohydrates
what enzyme is used for photosynthesis and photorespiration
RuBisCO
name the enzyme(s) involved in carbon fixation in C3 plants
Rubisco Ribulose-1,5-bisphosphate carboxylase-oxygenase responsible for carbon fixation by the Calvin cycle.
define carbon fixation
The capture of CO2 into an organic molecule (Rubisco = enzyme that is critical for carbon fixation in plants) makes inorganic carbon into organic carbon (sugar)
write the water balance equation for plants and define each variable
Water regulation in plants Wip = Wr + Wa - Wt - Ws Wip = internal water of a plant Wr = water taken from soil by roots Wa = water absorbed from the air Wt = water lost by transpiration Ws = water lost by secretions and reproductive structures, including nectar, fruit, seeds
list the variables in the animal water balance equation that are means of water acquisition
Wd = water taken by drinking Wf = water taken in with food Wa = water absorbed from the air
list the variables in the animal water balance equation that are means of water loss
We = water lost by evaporation Ws = water lost by secretions and excretions
list examples of C3 plantslist examples of C3 plants
Wheat, oats, rye, orchardgrass, legumes
list the variables in the plant water balance equation that are means of water acquisition
Wr = water taken from soil by roots Wa = water absorbed from the air
list the variables in the plant water balance equation that are means of water loss
Wt = water lost by transpiration Ws = water lost by secretions and reproductive structures, including nectar, fruit, seeds
explain the activity of ATP synthase
a mitochondrial enzyme localized in the inner membrane, where it catalyzes the synthesis of ATP from ADP and phosphate
what do ATP and NADPH stand for?
adenosine triphosphate (ATP) nicotinamide adenine dinucleotide phosphate (NADPH)
list the following in order from more negative to less negative water potential: air, leaf, root, soil, stem
air, leaf, stem, roots, soil
explain how deep roots can aid in water acquisition, give an example
ash juniper tap into water table and saturated soils
explain how dense pubescence helps plants maintain the proper water balance
block sun from transpiration
where does RuBisCo operate in C4 plants?
bundle sheath cell
the production of sugar occurs in ___ cells in C4 plants
bundle-sheath cells
where is sugar produced in C4 plants?
bundle-sheath cells
list the three phases of the Calvin cycle
carbon fixation, reduction, regeneration
explain why clayey soils and sandy soils have different water potentials
clay - water uptake difficult sand - water uptake easy
list examples of C4 plants
corn, sugar, millet, sorghum, & shrubs
how does PEP carboxylase operate/what does it do?
creates malic acid
explain how the root:shoot ratio changes with average annual precipitation
decreased rain/ increase root:shoot ratio increased rain/ decrease root:shoot ratio
explain the impact of decreasing soil water potential on plant water potential over a several days period
decreasing soil water potential decrease rate of water uptake/movement
give an example of an animal that seals its burrow
desert tortoise
explain how being drought/winter deciduous helps plants maintain the proper water balance
drop leaves to reduce rate of transpiration
explain the difference in the root system between plants of the same species that live in moist vs dry habitats
dry - long roots wet - shallow roots
light dependent reactions (light reactions)
energy source - EM (visible 380-760) - chlorophyll A/B same in all plants thylakoid membrane split H2O/photolysis - O2 released as by product products - ATP - NADPH - short term
light independent reactions (dark reactions)
energy source - chemical - ATP/NADPH stroma carbon fixation - CO2 into sugar 3 pathways - C3 - C4 - CAM
give the percentage of water kangaroo rats lose from evaporation and waste
evaporation - 70% waste - 30%
what does C4 stand for?
first product of carbon fixation is a 4-carbon compound
osmolarity
freshwater vs. saltwater - relationship of an aquatic organism to its environment
give the percentage of water kangaroo rats gain from free water in food and from metabolic water
gain from free water in food 10% from metabolic water 90%
photorespiration rates are ___ in C3 plants
high
the water use efficiency is ___ in C3 plants
high
the water use efficiency is ___ in C4 plants
high
water flows from ___ to ___ concentration
high to low
water moves from where it is in ____ concentration to where it is in ____ concentration
high to low
hypoosmotic
higher internal concentration of water and lower internal concentration of salt compared to the environment
what time of day is typically the hottest? coldest?
hot 3pm cold 6am
compare the sources of water gain and loss for humans and kangaroo rats
humans - gained from drinking/eating - loss from urine kangaroo rats - gained from meta water - loss from evaporation
compare the sugar production/yield of C3 to C4 plants
increase in C4
how do higher temperatures affect sugar production in C3 plants?
increase temp / decrease sugar production
what time of day is the transpiration typically the greatest?
increase temp increase transportation
give the relationship between vpd and evaporative water loss
increase vpd/ increase water loss evaporation
isosmotic
internal concentration of water and salts are equal to the concentration in the environment
a high vapor pressure deficit occurs with a ___ difference between the actual vapor pressure and the saturation vapor pressure
large
high water potential is ___ negative
less
the Calvin cycle operates in which light independent pathway(s) ___________
light-independent
explain how shallow roots can aid in water acquisition, give an example
long roots along top surface of soil cactus
photorespiration rates are ___ in C4 plants
low
low vpd results in ___ evaporative water loss high vpd results in ___ evaporative water loss
low vpd/ decrease loss water high vpd/ increase loss water
hyperosmotic
lower internal concentration of water and higher internal concentration of salt compared to the environment
what compound acts as a spatial intermediate between the mesophyll cells and the bundle sheath cells in the C4 pathway?
malic acid
explain the activity of cytochrome b6-f complex during the electron transport chain
mediate the transfer of electrons and of energy between the two photosynthetic reaction center complexes, Photosystem II and Photosystem I
name the cell(s) involved in photosynthesis in C4 plants
mesophyll bundle sheath cell (BSC)
where does PEP carboxylase operate in C4 plants?
mesophyll cell
the initial fixation of carbon dioxide occurs in ___ cells in C4 plants
mesophyll cells
low water potential is ___ negative
more
which plants operate the light dependent reactions?
most plants
water moves _____ its concentration gradient
move down concentration gradients
in terrestrial habitats there is a tendency for water to flow ____ organisms to the atmosphere
move down concentration gradients and the magnitude of those gradients from an organism to its environment is determined by whether an organism tends to lose or gain water from its environment and how quickly - Tendency for water to flow from organisms to the atmosphere
explain how migration helps animals maintain the proper water balance
move with seasonal weather changes to provide efficient water
explain how paraheliotropism helps plants maintain the proper water balance
parallel to sun to reduce transpiration
list two species that migrate in response to lack of water
phainopepla wildebeest
give three examples of extreme water acquisition discussed in class
phainopepla wildebeest couch's spadefoot toad - Trench digging - Fog basking - Metabolic water - water produced with the metabolism of carbohydrates, proteins, & fats
what does PEP stand for?
phosphoenolpyruvate (PEP) carboxylase
rank C3 and C4 plants by their photorespiration rates, their water use efficiency, and their yield/sugar production
photorespiration rates - C3 water use efficiency - C4 yield/sugar production - C4
compare and contrast photosynthesis and photorespiration
photosynthesis, carbon dioxide fixation takes place by the RuBisCO, photorespiration RuBisCO reacts with oxygen and it competes with the Calvin cycle
turgor pressure (ψp)
pressure exerted by water in a plant cell
explain how a thick cuticle helps plants maintain the proper water balance
prevent from transpiration
list the products and by-products of the light dependent reactions
products ATP/NADPH by products oxygen
the highest water potential is ___
pure water water potential = 0
explain the circumstances that would cause leaf water potential to increase midday
radiation/ temp changes - maintenance of high LWP is found to be associated with dehydration avoidance mechanisms
what is the energy source for photorespiration?
rubisco acts on oxygen instead of carbon dioxide - Rubisco reacts with oxygen, requiring 3.5 ATP and two NADPH
a low vapor pressure deficit occurs with a ___ difference between the actual vapor pressure and the saturation vapor pressure
small
list the following in order from highest to lowest water potential: air, leaf, root, soil, stem
soil, roots, stem, leaf, air (guard cells/mesophyll)
pneumatophore
specialized growth on the root system that helps with gas exchange; "knees"
matric forces (ψm)
tendency of water to adhere to a surface
vapor pressure deficit
the difference between the actual water vapour pressure and the saturation water vapour pressure at a particular temperature
cuticle
thick increase water lost beetle thin dry climates cuticle - plants - invertebrate/insects - reptiles
water-stressed plants would have a ___ water potential compared to well-watered plants
water potential decreases during water stress
estivation
when animals are dormant because weather conditions are very hot and dry. Their breathing rate, heart rate and metabolic rate decrease to conserve energy under these harsh conditions
list nine reason given why water is important to living organisms
- 75-95% water in cell cytoplasm - Solvent for chemical reactions - Metabolite in many cellular reactions: reactant → product ← - Thermoregulation - Nutrient transport - Waste elimination - Required for gas exchange in animals - Means of support in plants and some invertebrates - Living environment
list stresses that plants may experience due to too much water
- Limited gas exchange in submerged tissues - Accumulation of toxic substances in soil due to anaerobic conditions
water balance
- Maintaining the proper balance of water between an organism and its environment - Part of an organism's homeostasis
xerophyte
- Majority are succulent - plant species adapted for survival in arid environments
list three factors that impact plant water potential
- Solutes (ψs ) - Matric forces (ψm) - Pressure (ψp )
give an example of water as a reactant in cellular metabolism, give an example of water as a product of cellular metabolism
- Water is a by-product of cellular respiration when oxygen is coupled with hydrogen ions at the end of the electron transport chain - Cellular respiration is the process whereby animal cells take in food such as glucose and break it down through many mechanisms in order to produce energy the cell can do to fuel its growth and surviva
describe the migration of the wildebeest - direction, driving factor
- annual migration northwest, at the end of the rainy season (usually in May or June) - seasonal rains and the search for green grass
describe the estivation of the couch's spadefoot toad - timing, means of survival, means of arousal
- can last 2 yrs - sound/vibrations from rain underground - 5% meta rate - underground has increased relative humidity/ helps water balance
photorespiration
- competitive reaction with photosynthesis; oxygen (O2) attached to RuBP instead of CO2 - High photorespiration rate
explain how sealing the burrow helps animals maintain the proper water balance
- decrease temperature in hot periods - stable absolute humidity - increase relative humidity
describe the migration of the phainopepla - direction, timing
- from southern California to the desert Southwest to breed in the spring before flying to California coastal woodlands to do so again in summer - fall migration time of year - roots can penetrate and siphon food and water from the mesquite
explain how estivation helps animals maintain the proper water balance
- inactivity and metabolic reduction in response to a lack of water or high temperature - metabolism, respiration, and heart rate fall to low levels
aerenchyma
- interconnected gas filled chambers throughout the plant - Plant response to too much water
desiccation
- lose 89-90% moisture - no meta/no respiration - retain structure - fern spikemoss
explain how desiccation tolerance helps plants maintain the proper water balance
- loss 80% moisture - no metabolism - no photosynthesis - no respiration - fern/spikemoss
water-use efficiency
- ratio of the rate of CO2 fixation to water loss by transpiration - Lower water-use efficiency
describe the impact of a dramatic change in the ostrich blood plasma osmolarity
- red blood cells damage - increase velocity thick blood - fatal
explain how the cuticle thickness of an animal helps it maintain the proper water balance, give an example
Cicindela oregona/ tiger beetle increase cuticle thicks increase water retention
what does CAM stand for?
Crassulacean acid metabolism
name the cell(s) involved in photosynthesis in C3 plants
Mesophyll cells
how do aquatic organisms actively uptake water? salt?
Osmosis is movement of water down its concentration gradient across a semipermeable membrane
name the enzyme(s) involved in carbon fixation in C4 plants
PEP carboxylase
winter annual
Plants that germinate in the fall and complete their life cycle within one year Bluebonnet fall - germinate winter - overwinter basal spring - active growth, produce/ disperse seeds
which adaptation of plants to too much water is also referred to as knees?
Pneumatophores - specialized growth on the root system that helps with gas exchange; "knees"
if C3 and C4 plants produced the same amount of sugar which would lose more water?
C3
which light independent photosynthetic pathway is the most common?
C3
list the three pathways of the light independent reactions (dark)
C3 C4 CAM
describe the latitudinal gradient in the percentage of C3 to C4 plants describe the altitudinal gradient in the percentage of C3 to C4 plants
C3 requires cool and wet environments. C4 requires tropical and dry environments. 95% of the green plants are C3 plants.
if C3 and C4 plants lost the same amount of water which would produce more sugar?
C4
which habitats provide a competitive advantage for C4 plants over C3 plants?
C4 advantages - in warmer drier climates
how many times is carbon fixed in C3 plants? C4 plants?
C4 carbon fixed twice
how many extra ATP (over the C3 pathway) are used to operate the C4 pathway?
C4 pathway, it takes 5 ATPs 3 ATPs in the C3 pathway
where does the Calvin cycle operate in C4 plants?
C4 plants, the Calvin cycle occurs in the bundle-sheath cells (in C3 plants this occurs in the mesophyll cells).
water potential
Capacity of flowing water to do work (ψ) Factors affecting water potential - Solutes (ψs) - Matric forces (ψm) - tendency of water to adhere to a surface - Turgor Pressure (ψp) - pressure exerted by water in a plant cell Water potential gradient pure water, soil water, plant - root, leaves, dry air
what determines whether photosynthesis or photorespiration occurs?
Light intensity, carbon dioxide concentration, and temperature
list the two parts of the photosynthesis process
Light reactions - light dependent Dark reactions - light independent
give two units of water potential
MPa Bar - capacity of flowing water to do work
explain how the roots of an individual plant can respond to drought conditions
Water loss can be limited by stomatal closure and over the longer term by restricting shoot growth, leading to an increased root-to-shoot ratio
give the factors that determine whether an organism gains or loses water to its environment and how quickly
Water regulation in animals Wia = Wd + Wf + Wa - We - Ws Wia = internal water of an animal Wd = water taken by drinking Wf = water taken in with food Wa = water absorbed from the air We = water lost by evaporation Ws = water lost by secretions and excretions
