Microbes & Energy Flow-29 Flashcards
Population
formed when Individual microbial cells of a species proliferate
Communities
formed when Populations interact/communicate
Microbial Ecology:
the study of the
interrelationships among microorganisms and their environment
MICROBIOME
all microorganisms, and their genes, within a
particular environment
Draw redox in bacteria
The basis for energy transfer in cells
H2S ox to S
NADP+ red to NADPH2
NADPH2 ox to NADP+
CO2 red to (CH2O)n
NADP+
nicotinamide adenine dinucleotide phosphate
Energy from an oxidation is shuttled through an intermediate
(NADH/NADPH)
Carbon source
- Auto
- Hetero
- Carbon Dioxide (Inorganic)
- Organic
Energy Source
- Photo
- Chemo
- Light
- Chemical Compunds
AUTOtrophs
= Primary Producers
= Fix CO2
Self sufficient, do not require carbon
HETEROtrophs
= Decomposers
= Need fixed carbon, cannot use CO2 directly
Dependent on primary producers
CHEMOtrophs energy
= use chemical energy from either
C compounds = organic (Glucose)
Non C compounds = inorganic (H2S)
PHOTOtrophs energy
= use SOLAR energy
Photoautotrophs
Plants, Algae, Cyanobacteria use H2O as an electron source to reduce CO2, produce O2 as by product.
Green and Purple sulfur bacteria use H2S as an electron source, Not make O2.
Chemoautotrophs
Hydrogen, Sulfur, and Nitrifying bacteria, some archaea.
Photoheterotrophs
Green and Purple nonsulfur bacteria, some archaea.
Chemoheterotrophs
Aerobic respiration: most animals, Fungi, Protozoa, many bacteria.
Anaerobic respiration: Some animals, Protozoa, Bacteria, and Archaea.
Fermentation: some bacteria, yeasts, and Archaea.
Non-cyclic photophosphorylation
Oxygenic Photosynthesis
Electrons flow from H2O –> PSII –> PSI –> NADP+
Generate O2, ATP and NADPH
Cyclic photophosphorylation
Anoygenic Photosynthesis
Photosystem l (PSI) can work in absence of PSII Generates ATP but no O2 (anoxygenic)
Draw Light common resource
arrow down
Microbial mat in a marsh.
Layers of different coloured microbes
Cyanobacteria and algae Chlorophyll a (chloroplasts) = 500-550nm
Purple bacteria*= >800nm
Green bacteria*= 550-850nm
*Bacteriochlorophyll (membranes)
Outline how microbes exploit different environments
Light = common resource
Avoid competition by tuning their antenna to different wavelength.
Photosynthetic pigments have complementary absorption spectra
Metabolism: two linked but different processes
Energy (electrons) Building blocks (carbon as example)
Light profile dictates
photo vs chemotrophs
Carbon fixation dictates-
auto vs heterotrophs
Anoxygenic and oxygenic photosynthesis
(H2S)
H2O
Redox reactions
control the flow of energy, and the breakdown / buildup of molecules
Linked to different microbes in different ecosystems
