Bac metabolism Lec 4. 1 Flashcards
anabolism
process by which a cell is built from simple nutrients
catabolism
process by which a cell breaks down complex nutrients
Chemotrophic organisms
utilize energy rich compounds for catabolism and anabolism
Chemoorganotrophs
obtain their energy from the oxidation of organic compounds
Chemolithotrophs
obtain their energy from the oxidation of inorganic compounds
phototrophs
obtain their energy from light
Nicotinamide adenine dinucleotide (NAD) and Nicotinamide adenine dinucleotide phosphate (NADP) are carriers of
electrons/hydrogen
NAD/NADP function as a?
coenzyme with many different metabolic enzymes
NAD Coenzyme of coupled redox
reactions allows for?
electron transfer to occur between chemically dissimilar molecules, with the coenzyme acting as an intermediary by binding to different enzymes
NAD+/NADH–are freely_______, transferring electrons from one place to another in the cell
diffusible
NAD+ can be viewed as an?
energy sensor of a cell
The energy from redox reactions is conserved in the formation of certain
compounds that contain ______ _____ bonds. Example?
enery-rich phosphate bands
*ATP
fermentation and/or respiration are both examples of?
enery conservation
fermentaion means?
that ATP generation depends on substrate level phosphorylation within a single metabolic pathway involved in catabolism of organic molecules (such as glucose)
one good example of fermentation is?
glycolysis
glycolysis is?
an anoxic (not requiring oxygen) process and is divided into 3 major stages, each involving a series of individually catalyzed enzymatic reactions
during glycolysis, Streptococcus mutans produces? why?
lactic acid as a fermentation product in the oral cavity b/c of the enzyme Lactate dehydrogenase
what is the terminal enzyme in fermemtation pathways?
Lactate dehydrogenase
without Lactate dehydrogenase, S. mutans cannot produce ____ and cause ____?
produce lactic acid and cause caries
Respiration means? example?
that ATP generation depends on transferring electrons out of one catabolic pathway via an intermediary
*NADH into an electron transfer system followed by oxidative phosphorylation
In fermentation or respiration, the terminal electron acceptor can be supples what 3 ways?
1) externally supplied (repiration)
2) part of another anzymatic pathway
3) internally supplied (fermentation) as part of original pathway
what is the terminal acceptor type for respiration? Meaning ATP is produced via?
externally supplied
*ATP produced via oxidative phosphorylation
Aerobic respiration electron acceptor?
oxygen
Anaerobic respiration electron acceptor?
molecule other than oxygen (nitrate, sulfate, nitrite)
What forms the proton motive force in bacterial energetics?
When electrons are transported through an electron transport chain, protons are extruded to the outside of the membrane, forming the proton motive force.
3 things proton motive force provides energy to?
- used for ATP generation- ATP synthase utilizes PMF for generation of ATP
- used for the transport of nutrients -symporter and antiporter systems
- used for locomotion of the cell eg. flagellar motion
oxygen can be toxic why?
generation of reactive oxygen products
give examples of intermediary reactive oxygen byproducts from aerobic respirtation
hydrogen peroxide and superoxide
aerobic bacteria are protected from oxygen byproducts by what enzymes?
catalase
peroxidase
superoxide dismutase
why are anaerobic bacteria unprotected from oxygen?
they lack enzymes that remove or break down oxygen for them
common anaerobic bacteria in dental field?
Porphyromonas gingivalis
how is H+ returned to cytoplasm after e- transport systems?
H+ are returned, via membrane bound ATPase (ATP synthase), to the cytoplasm with the formation of ATP from ADP and PO4
