Different cycles Flashcards
what are the steps of the carbon cycle
- Photosynthesis
- Decomposition
- Respiration
- Combustion.
where does carbon cycle from
carbon cycles from the atmosphere into plants and living things
what is fossil carbon not used in
is not used by biological systems. Burning it contributes to the green house effect
how can microbes transfer organic and inorganic carbon
Microbes can transfer organic and inorganic carbon through autotrophic (fixation) and heterotrophic (decomposition) metabolism
what does organic matter mineralisation depend on
environmental factors
What are recalcitrant and xenobiotic compounds?
Recalcitrant xenobiotic compounds are able to penetrate into the soil pores, adsorb onto soil particles, allowing both vertical and horizontal movement via capillary and gravitational forces
what are the 4 major nutritional types
photoautotroph, chemoautroph, photoheterotroph and chemoheterotroph
when is nitrogen converted into multiple chemical forms
as it circulates among atmosphere, terrestrial, and marine ecosystems. The conversion of nitrogen can be carried out through both biological and physical processes
in local shortages what is nitrogen
a limiting factor most of the time
what do microbes decompose
proteins from dead cells and release amino acids
how’s ammonia liberated
by microbial ammonificaiton of amino acids
why is ammonia oxidised
to produce nitrates for energy by nitrifying bacteria
what is the productivity of many ecosystems limited by
fixed N
how it nitrogen fixed
fixed chemically by fertilisers
what are the 4 main components in the N cycle
- N-fixation (Azotobacter, Cyanobacteria ).
- Ammonification (Decomposers).
- Nitrification (Nitrosomonas & Nitrobacter).
- Denitrification (Pseudomonas & Bacillus).
what are Nitrogen-fixing microbes
-They live symbiotically with legume roots
-They provide the plant and surrounding soil with usable nitrogen
-E.g Rhizobium
what is involved in the sulphur cycle
-Recycles sulphate molecules
-Microbes break down proteins and amino acids to yield compounds like hydrogen sulfide
-Several bacterial genera transform hydrogen sulfide to sulfate Plants use the sulfate in amino acids
what are the 4 different forms of sulphur
-Organic sulphur compounds
-Sulphide
-Sulphur
-Sulphate
what is involved in the phosphorus cycle
-Inorganic phosphorus is solubilized by microbial acids
-Made available to plants and other microbes
-Is soluble in water
-Combines with calcium in calcium phosphate deposits of ancient seas.
