M5 LESSON 2 Flashcards
- function of vascular tissues
- mechanisms involved are either diffusion or osmosis
PLANT TRANSPORT PROCESS
transports WATER AND MINERALS
Process: TRANSPIRATION STREAM
XYLEM
transports SUCROSES AND AMINO ACIDS
Process: TRANSLOCATION
PHLOEM
MOVEMENT OF MOLECULES OR IONS from a region of HIGH concentration to
a region of LOW concentration
DIFFUSION
Diffusion Gradient of movement from HIGH to LOW
MOVING ALONG THE DIFFUSION GRADIENT
DOES NOT INVOLVE the use of energy
PASSIVE TRANSPORT
Diffusion Gradient of
movement from LOW to HIGH
MOVE AGAINST THE DIFFUSION GRADIENT
diffusion with a HELPER PROTEIN
SIMPLE DIFFUSION
utilizes helper proteins, e.g. channel and CARRIER PROTEINS
FACILITATED DIFFUSION
Rate of Diffusion is affected by
TEMPERATURE OF THE ENVIRONMENT
DENSITY OF DIFFUSING MOLECULE
MEDIUM OF DIFFUSION
CONCENTRATION GRADIENT
DIFFUSION OF WATER across a semi-permeable membrane
OSMOSIS
water moves from an area where water is HIGHLY CONCENTRATED to an
area where water is LOW CONCENTRATED
OSMOSIS
measure of the potential of water to move from one cell to another as influenced by solute concentration
OSMOTIC POTENTIAL
CONCENTRATION OF SOLUTES on either side of the membrane
TONICITY
TURGID CELL (normal), water concentration is LOWER in the
cell; OUT TO IN
HYPOTONIC
FLACCID, water moves in and out
ISOTONIC
PLASMOLYSED (shrinked), concentration of water is higher outside the cell; waters MOVES OUTSIDE
HYPERTONIC
EXERTED PRESSURE by the cell’s fluid content against the cell wall
TURGOR PRESSURE
- SWELLING OF TISSUES often to several times their original volume
- INITIAL STEP in the germination of seeds
IMBIBITION
- UPTAKE OF MINERALS or ions into the ROOT HAIR CELLS, an example of active
transport - movement of molecules AGAINST THE CONCENTRATION GRADIENT
ACTIVE TRANSPORT
plant transport water through xylem
WATER MOVEMENT
water moves through plants by a combinations of two factors:
adhesive and cohesive properties of water
transpiration
attraction between water molecules due to their HYDROGEN BONDS
COHESION
attraction between water and other substances
ADHESION
- movement of water through the plant depending upon the rate of
transpiration - PULLS THE WATER UP through the plant
TRANSPIRATION
Factors Affecting Transpiration Rate
HUMIDITY
WIND
TEMPERATURE
LIGHT
causes transpiration to be DECREASED
HUMIDITY
INCREASES EVAPORATION and thus transpiration; wind removes
water vapor around leaves, increasing transpiration
WIND
generally causes an INCREASE IN THE RATE OF TRANSPIRATION;
STIMULATES THE OPENING OF THE STOMATA
LIGHT
INCREASES EVAPORATION and thus transpiration
TEMPERATURE
plants transport food through their
PHLOEM
the ultimate “source” of sugars for plants is the ______, as they store
sugars and are greatly utilized during the growing season
ROOT
- explains the movement of sugars through a plant
phloem-loading - H+ ions activity transported out of phloem cell; High H+ ion conc.
builds up outside the cell - H+ ions flows back into the cell, energy is released to facilitate entry
of sucrose
PRESSURE-FLOW HYPOTHESIS
