Lecture 9

April 28, 208

Nutrients

1. Requirement for nutrients

Redfield ratio

• elemental composition
• stoichiometry of typical molecules

 

2. Inorganic nutrients in water

form and relative abundance

• C
  • CO2, H2CO3, HCO3-, CO3--
  • organics
• N
  • NO3- and NO2-
  • NH3/NH4+
  • urea
  • organics as N source (amino acids)
  • N2
• P
  • all forms of H3PO4, H2PO4-, HPO4--, PO4---
  • org-PO4
  • colloids
• Si
  • Si(OH)4
• S
  • SO4
  • DMS - haze forming
• Fe
  • Fe3+ and Fe2+
  • chelated, complexed forms
  • siderophores
• Cu, Ni,
  • Cu2+ bound and free
  • ion activity, not amount
    
  • links to assimilation of other nutrients

3. Organic nutrients

• vitamins
  • B12
• amino acids
  • H2O2 link

4. Transport and assimilation

• 3 steps
  • across boundary layer
    relates to hydrodynamics
  • transmembrane transport
    
    • porter site - active or facilitated transport
    • diffusion -
  • assimilation
    • synthesis and storage pathways
      

5. Kinetics of uptake from medium

nutrient uptake through saturable porter

derivation of MM kinetics