Microbes & Energy Flow Flashcards
How many microbes are cultured and characterised?
tens of thousands
What has been identified by pure cultures?
Mostly pathogens or fast growing organisms
What does pure cultures ignore?
Complex interactions and the fact that most organisms live in communities
What many prokaryotes are on the planet?
9.2-31.7x10^29
What portion of the biomass do prokaryotes make up?
20-50%
Most organisms…
cannot or have not been isolated in pure culture
What is identification now done using?
Genetic fingerprints
What is currently available in databases?
Millions of unique 16S rRNA sequences (molecular barcode)
What are majority of the genes in the database?
From uncultivated bacteria (of unknown function)
what is the uncultured microbial world?
Far greater than the cultured world
How are populations formed?
When individual microbial cells of the same species proliferate (grow)
How are communities formed?
Populations of different species interacting and communicating
What is microbial ecology?
The study of the interrelationships among micro-organism and their environment
What gave rise to the term microbiome?
Molecular tools
What is microbiome?
All microorganisms, and their genes, within a particular environment
What does breaking a compound result in?
Harvesting of building blocks and energy
What would happen when building a compound?
energy would be needed to create a bond and a building block would also be needed to attach to the bond
What is the basis of energy transfer in cells?
Redox reactions
What is there for every action?
An equal and opposite reaction (example= for every oxidation there is a reduction)
What happens with energy from an oxidation?
It is shuttled through an intermediate (NADH/NADPH) and then used to make carbohydrates
What are autotrophs?
Primary producers which are self sufficient and do not require carbon
What do autotrophs do?
Fix CO2
What are heterotrophs?
Decomposers which are dependent on primary producers
What do heterotrophs do?
Need fixed carbon, cannot use CO2 directly
What process requires energy?
Carbon»>Macromolecules»>Cells
What do chemotrophs do?
Use energy from inorganic or organic compounds (electron donors)
What are organic compounds?
Carbon compounds
What are inorganic compounds?
Non-carbon compouns
What do phototrophs do?
Use solar energy from sunlight
What are the two types of photosynthesis (phosphorylation)?
Cyclic (anoxygenic) and non-cyclic (oxygenic)
What happens in non-cyclic phosphorylation?
Electrons flow from H2O»>Photosystem 1»>Photosystem 2»>NADP+
What is generated from non-cyclic phosphorylation?
Oxygen, ATP and NADPH
What happens in Cyclic Phosphorylation?
Photosystem 1 can work in the absence of Photosystem 2. There is no splitting of water or reducing of NADP+
What is generated from cyclic phosphorylation?
ATP but no oxygen
What is similar between cyclic and non-cyclic phosphorylation?
Both processes use light for energy and fix carbon
What is different between cyclic and non-cyclic phosphorylation?
Only one generates oxygen
How do many different microbes in the same environment avoid competition?
They specialise so that they are slightly different to each other
What is an example of microbes specialising?
So that all of the microbes get light, the photosynthetic pigments have different absorption spectra
What is a common resource?
Light
What is done to avoid competition of light?
Microbes tuning their antenna to different wavelengths
