13 - Transport in Plants Flashcards
Understanding Translocation & Transpiration
What is passive transport?
moves mol.s short distances/across membranes
wX added energy
What are the types of passive transport?
- Simple Diffusion
- Facilitated Diffusion
- Osmosis
What’s diffusion?
net movement of a molecule population down its
concentration gradient wX energy
Simple diffusion
molecules crossing the phospholipid bilayer on the concentration gradient [high -> low] wX energy
Facilitated diffusion
crossing of a membrane through a transport protein
Osmosis
H2O net diffusion from [high -> low water] concentration of water (against solute concentration gradient) until equilibrium
What processes are short distance transport & what are long distance transports?
Short - diffusion (can easily cross one cell layer)
Long - crossing various layers of cells or crossing distances (like roads, trees, etc)
Across a membrane, molecules move via:
- Simple Diffusion
- Facilitated Diffusion
Molecule: Simple diffusion
Small & non-polar
Molecules: Facilitated
Large & charged/polar molecules
Tonicity
ability of a surrounding solution to cause a cell to gain or lose water
(solute molecules are non-penetrating -> ,’, water is the only thing that can move
across the membrane)
Concentration gradient
process by which mols move down high to low
Diffusion Factor: Concentration gradient
greater difference in concentration will increase diffusion rate
Diffusion Factor: (B1 - TEMPERATURE)
Higher temp -> ↑ mol dancing & ↑ diff. rate
Diffusion Factor: molecular mass
Bigger mols < smaller mols in speed
