Microbial carbon cycle Flashcards
What is the largest carbon reservoir?
Trapped organic carbon, e.g. coal, natural gas, petroleum
Define an inorganic compound
Compounds that lack carbon-hydrogen bonds
Define an organic compound
Carbon-based compounds that are primarily made of carbon and hydrogen
What are the two types of reactions that microorganisms can use to gain energy?
Chemical and photochemical
Describe a phototroph
Using light as the energy source for metabolism
What are the two types of phototroph?
Anoxygenic and oxygenic
Give examples of anoxygenic phototrophs
Purple/green non-/sulphur bacteria, and cyanobacteria under certain conditions
What do oxygenic phototrophs do?
Give three examples
Produce oxygen
Higher plants, eukaryotic algae, and cyanobacteria
What is the difference between oxygenic and anoxygenic phototrophs?
Oxygenic phototrophs use light to generate reducing power (NADPH) from water, anoxygenic phototrophs generate reducing power (NADH) from reduced in/organic compounds
How do phototrophs fix CO2 in the dark?
ATP is used to reduce CO2 to organic compounds (CO2 fixation)
Most commonly uses the Calvin Cycle
Describe anoxygenic photosynthesis
Light-mediated ATP synthesis with e- transfer down potential gradient
(cyclic photophosphorylation)
What are the two separate light reactions in oxygenic photosynthesis?
Photosystem II and I
Forms the Z-scheme
Describe photosystem II in oxygenic photosynthesis
Involved in photolytic splitting of water (oxygen production)
Describe photosystem I in oxygenic photosynthesis
Equivalent to anoxygenic photosynthesis (cyclic photophosphorylation)
Generates ATP
What are the three major processes of carbon oxidation by heterotrophs?
Glycolysis, tricarboxylic acid cycle (TCA), e- transfer/oxidative phosphorylation
