plant transportation and nutrients Flashcards
what is the simplest form of passive transport?
simple diffusion is simplest form of passive transport
- no metabolic energy
- moves down concentration gradient
what is active transportation?
requires metabolic energy (ATP)
based in H+ pumps
H+ gradient maintained through ATP
H+ diffusion into cell powers uptake of solutes
what is symport active transportation?
material transported in same direction as movement of H+ and solute, organic uptake
energy released brings molecule through with it
what is antiport active transport?
mineral transported in opposite direction to movement of H+ and solute, Na+ export
energy released expels a proton
what is diffusion?
the spontaneous movement of molecules or particles along a concentration gradient
what is osmosis?
special case of diffusion
water molecules diffuse across selectively permeable membrane from area of high concentration to a low concentration using aquaporins
what is a hypertonic solution?
higher concentration outside of the cell
water moves out of cell
what is an isotonic solution?
equal concentration of solutes inside and outside of cell
no net movement of water
what is a hypotonic solution?
higher concentration of water inside of cell
water moves into the cell
what happens of plant cells in a hypertonic solution?
cells becomes plasmolyzed
what happens to plant cells in a hypotonic solution?
cells become turgid
how do cells not burst in a hypotonic solution?
the tonoplast and water will go into a vacuole and create pressure against the cell wall. the cell wall will push against and will stop the cell from expanding
what are the properties of water molecules?
cohesion
adhesion
H-bonding
what is H-bonding in water?
can form 4 weak H-bonds with adjacent molecules
what is the cohesion property of water?
water molecules sticking to itself
good for plant vascular system
what is the adhesion property of water?
pulls up the sides of a glass tube
what characteristics of water does the xylem use?
cohesion and adhesion
what is transpiration?
evaporation of water out of plants
greater than water used in growth and metabolism
what are cohesion-tension mechanism of water transport?
evaporation from mesophyll walls
replacement by cohesion (H-bonds) water in xylem
tension, negative pressure gradient, adhesion of water to xylem walls adds to tension
what is the stoma?
transpiration losses of water must be regulated to prevent rapid desiccation
guard cells help control internal environment
how does the stomata open?
when potassium is mostly in the guard cells
how does the stomata close?
when potassium is mostly in the epidermal cells
what is the physiology of a stomata?
must balance water loss and carbon dioxide uptake
opens to increase photosynthesis
closes under water stress
what is an arid adaptation?
xerophytes have adaptations to hot, dry environments
- thickened cuticle, sunken stomata, water storage in stems,
modified leaves
seen in CAM plants
organic compounds in plants
macromolecules broken down into constituents for transport across cell membrane
what is translocation of macromolecule constituents?
long distance transport of substances via phloem
flow though sieve tubes whose ends calls studded with pores
what are companion cells?
connected to phloem through plasmodesmata
loads and unloads molecules in the phloem
active unloading and loading into the phloem
what is a source?
any region of plant where organic substances are loaded into phloem
what is the sink?
any region of plant where organic substances are unloaded from phloem
what is the pressure slow mechanism that mover substances in the phloem?
bulk flow under pressure from sources to sinks
- based in water potential gradient
where do most of plant nutrients comes from?
photosynthesis
how many essential elements do plants need?
17
if absent, can affect the growth and survival of plant
what does the soil determine?
where and how well plants will grow
what are symptoms of nutrient deficiencies in plants?
stunted growth, leaf colour, dead spots, abnormal stems, chlorosis
macronutrients are essential in what amount?
large amounts
micronutrients are essential in what amounts?
trace amounts
root systems
extensive root systems are adaptations to limited mineral nutrients
roots have mechanisms to increase uptake
what are mycorrhizae?
symbiotic associations between fungus and roots of plants
gives plant phosphorous in return for sugars
what are the three pathways of water into roots?
apoplastic pathway
symplastic pathway
transmembrane pathway
what is the apoplastic pathway?
water doesn’t cross cell membrane, diffuses through nonliving regions including cell walls and air spaces
what is symplastic pathway?
water crosses membrane, often uses plasmodesmata, diffuses through cytoplasm
what is transmembrane pathway?
water crosses plasma membranes and perhaps tonoplasts
what is the casparian strip?
root endodermis forces apoplastic water to symplast
to protect from dangerous substances in soil
allows plant to decide what to take in
where is there active transport in the root system?
minerals into symplast
at casparian strip across membrane
soil
complicated mixture
soil minerals particles, compounds, ions, decomposing organics, water, air, organisms
amount of soil particles determines soil properties
what are the 4 horizons of soil?
0 horizon
A horizon (topsoil)
B horizon (subsoil)
C horizon (parent material)
what is 0 horizon?
surface material
find organic mater
what is topsoil?
has most biological activity and usually most fertile, most roots
what is subsoil?
accumulates nutrients/ minerals, woody roots
what is parent material?
no organic material, partially weathered fragments and grains of rocks
what are nitrogen’s limitations?
abundant element in are, most limiting to plant
triple bond requires specific enzyme, so plants rely on bacteria to change nitrogen into ammonia
what is nitrogen cycling?
bacterial ammonification breaks organic N compounds into ammonia
bacteria nitrification oxidizes ammonia to nitrate
plant converts nitrate to ammonia to assimilate nitrogen into organic compounds
what is nitrogen fixation?
most nitrogen is fixed by plant symbioses with bacteria
legumes form root nodules with rhizobium or bradyrhizbium
