Anoxygenic Photosynthesis Flashcards
pigments and early phototrophs
microbes may have developed pigments to use UV wavelengths to seek out heat and move itself toward the nutrients available in those warmer waters
anoxygenic photosynthesis
photosynthesis that does not PRODUCE oxygen
process of anoxygenic photosynthesis
pigment collects photons (particle of light), energizing the pigment and becoming a reductant (reduces the electomagnetic potential of the pigment)
Dark reactions: what they do? What they use?
role: carbon fixation - turning inorganic carbon to organic carbon
why is it called a dark reaction
it doesn’t use the light, it just uses the products of the light reactions
light reactions
role: light energy is directly used through conversion to/generation of chemical energy
classifications of anoxygenic photosynthesizers
green and purple sulfurs
green and purple non-sulfurs
5 Characteristics of green sulfer
- bottom of microbial mat - need anoxic environment
- greyish green
- sulfide-rich (H2S)
- H2S, (S2O3)^2-, Fe^2+ as PED
- can internally store S
waste products of glucose and sulfate
autotrophic (uses inorganic carbon to fix carbon for use)
4 Characteristics of Green Non-sulfur in anaerobic environments
looks dark green
photolithoautotrophic
lower in mat
using sulfide and H2 as PED
Characteristics of Green Non-sulfur in aerobic environments
yellow or orange when not using light
chemoorganoheterotrophic
higher in mat, using organic carbon wastes of other microbes
Purple Sulfur characteristics
pinkish/light puple
aborb shorter wavelengths, go deeper into deeper waters
anoxic, sulfide-rich environs
syntrophic with Sulfur reduction bacteria
able to store sulfer internally
can use Fe2+ and H2
photolithoautotrophic?
Purple non-sulfur characteristics
Dark purple to red
not found with purple sulfur, don’t like sulfide-rich
inorganic PEDs like Sulfide, Iron, hydrogen gas (photoauto)
small organics like acetate) acting as photolithoheterotrophs
syntrophic relationship with fermenters
