Fermentation
an anaerobic metabolic process whereby microorganisms, such as bacteria and yeast, break down carbohydrates (like glucose) to produce energy (ATP) without oxygen
Alcoholic fermentation
a type of anaerobic metabolism in which certain organisms break down glucose (or other sugars) to produce ethanol and carbon dioxide as end products.
Homolactic fermentation
a type of anaerobic fermentation in which organisms convert glucose almost entirely into lactic acid (lactate)
Heterolactic fermentation
another type of anaerobic fermentation, but unlike homolactic fermentation, it produces multiple end products instead of just lactic acid.
- Lactic acid (lactate), Ethanol, Carbon dioxide (CO₂)
Mixed acid fermentation
a type of anaerobic fermentation in which bacteria break down glucose into a mixture of different acids and other products.
- lactate, acetate, succinate, formate, ethanol, H2, CO2
Aerobic respiration
the process by which cells use oxygen (O₂) to completely break down organic molecules (like glucose) to produce ATP.
- most efficient process
Anaerobic respiration
a type of respiration where cells:
🔹 Use an electron transport chain (ETC)
🔹 But use a final electron acceptor other than oxygen
Electrically conductive pili
specialized protein filaments on certain bacteria that can transfer electrons outside the cell.
oxygenic phototrophy
a type of photosynthesis where organisms:
- Use light energy
- Use water (H₂O) as the electron donor
- Produce oxygen (O₂) as a byproduct
anoxygenic phototrophy
a type of photosynthesis where organisms:
- Use light energy
- Do NOT use water as the electron donor
- Do NOT produce oxygen
bacteriochlorophyll
a photosynthetic pigment found in certain bacteria that allows them to capture light energy for photosynthesis.
cartenoids
accessory pigments found in photosynthetic organisms that:
- Absorb additional wavelengths of light
- Protect cells from light damage
bacteriorhodopsin
a membrane protein in archaea which functions as a light driven proton pump
- generates PMF
- no ETC
- purple is retinal
what is the electron carrier in anabolism?
NADPH
what is anabolism?
cells breaking down material and resynthesizing new ones; this requires a lot of energy
NADPH
an electron carrier that holds high-energy electrons used mainly for biosynthesis (anabolism).
how do autotrophs fix CO2?
- Calvin cycle and reductive TCA cycle
- sometimes Hydroxypropionate bi-cycle, reductive acetyl CoA pathway, and 3-hydroxypropionate/4-hydroxybutyrate pathway
What is the Calvin cycle?
a series of reactions that:
- Fix carbon dioxide (CO₂)
- Use ATP and NADPH
- Build organic molecules (like sugars)
- aka reductive pentose phosphate pathway
RuBP
ribulose-1,5-bisphosphate: it is the CO2 acceptor in the calvin cycle and requires ATP to be regenerated
- breaks down into G3P
RuBisCO
the enzyme that:
- Catalyzes the first step of the Calvin cycle
- Fixes CO₂ onto RuBP
where does the Calvin cycle occur?
in the carboxysome for some bacteria
- in the stroma of chloroplasts in some euk
what are the three phases of the Calvin cycle?
- carboxylation phase
- reduction phase
- regeneration phase
what is the reductive TCA cycle?
a carbon fixation pathway that runs the citric acid cycle in reverse.
- Instead of breaking down acetyl-CoA to CO₂ (like the normal TCA cycle), it:
- Uses CO₂
- Uses reducing power
- Builds organic molecules
Assimilation
incorporation of inorganic molecules into organic ones
