Lecture 29: microbes & energy flow Flashcards
most organisms cannot be or have not been
isolated in pure cultures
identification of organisms can now be done using
genetic ‘fingerprints’
the uncultured microbial world is
far greater than the cultured world
individual microbial cells of a species proliferate to form a
population
populations interact/communicate to form
communities
microbial ecology is
the study of the interrelationship among microorganisms and their environment
microbiome is
all microorganisms, and their genes, within a particular environment
enrichment cultures provide
specific temperature and chemical conditions that encourage growth of specific groups of microbes
enrichment cultures are examples of
mesocosms
mesocosms are
an experimental system that stimulates real-life conditions as closely as possible
metabolism can be broken in to two aspects
- catabolism
- anabolism
harvesting building blocks can release
energy
reduction-oxidation in bacteria:
H2S is
oxidised to S
reduction-oxidation in bacteria:
following H2S oxidisation NADP+ is
reduced to NADPH2
reduction-oxidation in bacteria:
following NADP+ reduction NADPH2 is
oxidised to NADP+
reduction-oxidation in bacteria:
Following NADPH2 oxidation CO2 is
reduced/fixed to form a carbohydrate (CH2O)n
for every oxidation action in a cell
there is an equal and opposite reduction reaction
autotrophs are ….. of CO2
primary producers
autotrophs are able to
fix CO2
heterotrophs are ….. of CO2
decomposers
heterotrophs cannot use
CO2 directly, need fixed carbon
chemotrophs use
chemical energy
sources of chemical energy are
- organic
- inorganic
phototrophs use
solar energy
non-cyclic photophosphorylation generates
oxygen, ATP and NADPH
cyclic photophosphorylation generates
ATP but not oxygen
cyclic photosynthesis is
anoxygenic
non-cyclic photosynthesis is
oxygenic
both cyclic/non-cyclic photosynthesis use
light for energy
both cyclic/non-cyclic photosynthesis fix
carbon
non-cyclic photosynthesis splits water
to produce products
many microbes use ….. as an energy source
light
to avoid competition microbes absorb
different wavelengths of light
microbes absorb different wave lengths of light by
tuning their antenna to different wavelengths
oxygen dependent organisms can live in
anoxic environments
organisms can ….. their electrons from ….. into ….. zones so they can still breath
- shuttle
- anoxic
- oxic
organisms shuttle electrons using
self made cables