Lecture 7: Mineral Nutrition Flashcards
organic materials come from
C, H, Os
atmosphere and water
inorganic materials come from
soil and water
Types of transport processes
- Bulk flow
- Diffusion
- Osmosis
- Facilitated transport
Bulk flow
- driven by pressure difference between two ends
Diffusion
- due to inherent thermal energy of molecules
- it involves no applied force
- concentration gradient provides direction
Osmosis
special case of diffusion
- diffusion across selectively permeable membrane (allows solvent but not solute to go through)
Facilitated transport
by carrier proteins, membrane channels and energy requiring pumps
symporter
two molecules move across membrane together
antiporter
two molecules move separately across the membrane
Routes of travel
- Transmembrane route: via water channels
- Apoplastic route: within porous cell walls (Caspian strip blocks this route)
- Symplastic route: via plasmodesmata
source tissue
leafs/stem
sink tissue
flower, young leaves and roots
moving photosynthesis products
- uploaded in phloem of source tissue, transported in phloem and then unloaded in sink tissue
What makes an element ESSENTIAL?
- if you take the element out of the solution, the plant wont grow or complete its life cycle
- the element cannot be replaced by a similar element
- its lack/absence must produce a specific deficiency symptom
soil particles
negatively charged therefore will bind with cations
biological nitrogen fixation
root nodule develops in response to nitrogen fixing bacteria
- these bacteria are attracted by particular signalling compounds secreted by plant roots in to the surrounding soil
parasitic plants
attach to host plant and use up nutrients by parasitizing other plants
