Transport Process Flashcards
Plant Basic Types of Transport
- Short-distance transport
- Long-distance transport
- transfer basic nutrient, cells that have them to cells that need them
- it is necessary to survival of internal plants.
short-distance transport
- transport between nonadjacent cell
- absolutely not essential in construction of large plants
- it is adaptive especially for land plants
long-distance transport
- makes selectively advantageous for shoot to grow upward
- mechanism by which nutrients are channeled to specific sites.
vascular tissue
this is related to transport processes that inhibit movement of substances
isolation mechanism
Three (3) types of membrane
- Free permeable membrane
- Completely permeable membrane
- Differentially/ Selective permeable membrane
Allows all solutes to diffuse through and have little biological significance
free permeable membrane
does not allow anything to pass through and occur as isolation barrier
completely impermeable membrane
allow only certain substance to pass through
differentially/ selective permeable membrane
all __ __ cell membranes are differentially permeable
lipid/protein
- Simplest Method movement of particles in solution
- High concentration to Low concentration
diffusion
- Diffusion of water through membrane.
osmosis
allows the water molecule movement to rapidly move
aquaporins
uses membrane bound molecule called MOLECULAR PUMPS that use energy of ATP to force molecule across the membrane
active transport
what is used in active transport
molecular pumps
is a free energy, has capacity to do work
water
capacity to do works for chemicals
chemical potential
When water adheres to substance, water molecules form __ __ to the material and are not as free to diffuse; capacity to work is __
- hydrogen bonds
- decreased
is the water’s chemical potential
water potential
water potential can be increased by;
- heat
- pressure
- elevation
three components of water potential
- osmotic potential
- pressure potential
- matric potential
ψπ
osmotic potential
ψp
pressure potential
ψm
matric potential
ψ
water potential
effect that pressure has on water potential
pressure potential
effect that solutes have on water potential
osmotic potential
water’s adhesion to non-dissolved structures such as cell walls, membranes, and soil particles
matric potential
ψ = ?
(formula)
ψπ + ψp + ψm
ψπ:
__ for pure water, __ for all solutions
- 0.0
- negative
ψp:
can be either __ or __
- positive
- negative
ψm:
always __ and usually insignificant except for relatively __ materials
- negative
- dry
ψ:
for living cells, always __ or __
- 0.0
- negative
movement of water is related to __ __
water potential
water moves from regions where water potential is relatively __ to regions where water potential is relatively more __
from positive to negative
Water moves whenever there is a __ in water potential within the mass of water
difference
If the water potentials of two regions are equal, the regions are in __
equilibrium
Water potentials must always be considered in __ _ __
pair or groups
water can move between regions in the plant if the water potentials of the regions are __ __
not equal
Knowing one single water potential __ __ __ us to predict whether water will move
does not allow
To transport various materials such as water, sugars, minerals, and hormones, most plant cells communicate with their __ __
neighboring cells
short-distance intercellular transport cells
- guard cells
- motor cells
- transfer cells
fine cytoplasmic channel that pass through primary cell walls which interconnects living cells
Plasmodesmata
One continuous mass of all the protoplasm of one plant
symplast
other ways of material transport across the plasma membrane
- osmosis
- molecular pumps between plasma membrane
- fusion between transport vesicle and plasma membrane
- refers to both the wall and intercellular spaces wherein most molecules can move through easily
- large, mostly intercellular space where molecules usually move towards the surface of the glands
- mostly cell walls among the nonglandular regions.
apoplast
are pairs of epidermal cells that control gas diffusion by regulating the opening and closure of stomatal pores
guard cells
At night: Guard Cells are __ and have __ __ __. Guard cells and adjacent cells are in __ __
- shrunken
- little internal pressure
- hydraulic equilibrium
At sunrise: __ is pumped into guard cells, raising __ __
- potassium
- solute concentration
At morning: Osmotic potential and water potential become __ __, and water flows in, causing guard cells to __ _ __ the pore
- more negative
- swell and open
At morning : As pressure builds, pressure potential __, counteracting the falling __ __
- rises
- osmotic potential
- Bulliform cells
- large colorless cells that are present close to the mid-rib in the upper surface of many monocot leaves
motor cells
motor cell are also known as
Bulliform cells
- assist in the rolling of leaves to avoid water loss through transpiration
- govern the process of transpiration
- unfold the leaves when the conditions are right
bulliform cells or motor cells
move slowly and reorient themselves
sensitive plant (Mimosa pudica)
leaf can close rapidly, in less than a second
venus flytrap (Dionaea muscipula)
sensitive plant
Mimosa pudica
venus flytrap
Dioinaea muscipula
Motor cells are similar to guard cells because they accumulate or expel __ and adjust their water __ and __
- potassium
- potential and turgidity
- involved in delivery of nutrients between generations and in the development of reproductive organs
- facilitate the exchange of nutrients that characterize symbiotic associations
- occur across all taxonomic groups in higher plants and also in algae and fungi.
Transfer cells
The rate at which the materials can be transported depends on the __ __ present
molecular pumps
The __ the membrane, the __ molecular pumps it can hold
- larger
- more
Specialized transfer cells:
WALLS
- __ on the outer surface
- __ and __ on the inner surface
- smooth on outer
- finger-like and ridge-like on inner
Specialized transfer cells:
PLASMA MEMBRANE
- __ __ against all of the convolutions; has a larger surface area if the walls are __
- pressed firmly
- flat
transfer cells with cell wall ingrowths
companion cells
Transfer cells are found in:
- where rapid short distance occur
- glands secreting salts
- areas that pass nutrients to embryos
- where sugar is loaded in or out of phloem
long distance transport
- phloem
- xylem
locations from which nutrients and water are transported
Sources
example of main sources
leaves
diverse locations where phloem sap is transported
Sinks
area of the plant where the substrate can be kept is referred to as the __
sink
actual volume of sugars and other nutrients that phloem transports per hour, excluding water
mass transfer
Mass transfer divided by the phloem’s cross-sectional area to get the
specific mass transfer
__ __ __ of phloem, which are living cells, are used for long-distance transport
sieve tube cells
used to load phloem because conducting-cell plasma membranes are permeable to monosaccharides and not to polysaccharides, but to disaccharides
polymer trap mechanism
phloem sap is under pressure, there is a risk of __
bleeding
Two mechanisms that seal broken sieve elements
- P-protein
- Callose
congeals into a tangled mess in the direction of the break
p-protein
formed when p-protein is congealed
p-protein plug
serves as a temporary cell wall in response to stress or damage
callose
type of tissue in vascular plants that transports water and some nutrients from the roots to the leaves
Xylem
long cells that help transport xylem sap and also provide structural support
Tracheids
shorter than tracheids, but also help conduct water
Vessel Element
connects each vessel element to form one continuous vessel
Perforation plate
a tissue that makes up most of the soft parts of the plans, and long fibers that helps support the pant.
Parenchyma Cell
Water is an essential nutrient for plants and comprises up to __ of plant’s tissue
95%
Properties of water
- adhesive
- cohesive
water molecules stick to other substances
adhesive
water molecules strongly bind to each other
cohesive
- The most widely accepted model of how water is transported through xylem
- essentially combines the process of capillary action with transpiration, or the evaporation of water from the plant stomata
cohesion-tension hypothesis
Three stages of cohesion-tension model
- transpiration
- tension
- cohesion
- occurs because stomata are open to allow gas exchange for photosynthesis
- deepens the meniscus of the water in the leaf, creating negative pressure (tension or action)
transpiration (evaporation)
- created by the transpiration “pulls” water in the plant xylem
- drawing water upward in much the same way you draw water upward when you suck on a straw
tension
water sticking to each other, causes more water molecules to fill the gap in the xylem as the top most water is pulled through stomata.
cohesion
For every __ of height, leaf water potential must be at least __ __ __ than water potential.
- 10 meters
- 0.1MPa more negative
plants where gravity assist water movement
pendent epiphytes
loss of water vapors through stomata surrounded by specialized guard cells. 90% of total water loss from plants through transpiration process
stomatal transpiration
Mechanism of stomatal transpiration
- osmotic diffusion
- opening and closing of stomata
- simple diffusion of water vapor
primarily caused by a water deficit, such as a drought or high soil salinity
Water stress
release of abscisic acid
leaves dehydration
