Energy without Oxygen Flashcards
1
Q
E. Coli respiration donors
A
- NADH
- Lactate
- Hydrogen
- Formate
- Alpha-Gly-P
- Succinate
2
Q
E. Coli respiration acceptors
A
- O2 - best
- Nitrate
- Fe3+
- DMSO
- TMANO
- Fumarate
3
Q
Oxygen’s redox potential
A
+860 mV
4
Q
When using non-O2 acceptors
A
The cell always gets less energy
5
Q
The next best acceptor
A
- NO3
- 421 mV
6
Q
Common characteristics of electron transport chains
A
- all start with low Eo’ potential substrates
- end with higher Eo’ substrates
- all employ electron carriers
- all contribute to the proton motive force.
7
Q
All electrons will go through the ____ in the ETC
A
- quinone pool
- it’s not necessary to match up a donor and acceptor
8
Q
Paracoccus denitrificans
A
- uses normal respiratory chain
- but can grow anaerobically when O2 not available.
- only pumps 4 H+
- less ATP for anaerobic respiration
9
Q
when NO3- available
A
- the respiratory chain is shortened, because the redox difference between O2 and NO2- is large.
10
Q
Camplyobacter
A
- unable to utilize NADH as a respiratory donor
- H2 and formate are respiratory donors
- uses O2, NO3, NO2, DMSO, and possibly fumarate as acceptors.
11
Q
Why we know there is at least one more donor?
A
- mutant strains that cannot oxidize either H2 or formate and these bacteria are able to grow on complex media, although not as well as wild type strains.
12
Q
Geobacter and ferric iron
A
- Uses ferric iron to accept the electrons
13
Q
Wollinella succinogenes
A
- oxidizes formate to take e-
- 2 protons pumped but produces H+ outside to contribute to PMF
- reduces nitrate
14
Q
Pyrococcus furiosus
A
- use a respiratory chain and F0F1 ATPase to make ATP
- chain begins and ends on the extreme reducing side of the redox tower
- starts with a reduced ferredoxin and ends with protons being reduced to hydrogen (H2)
15
Q
General rule
A
- greater difference between the redox potential of donor and acceptor compounds = more protons pumped = greater potential for ATP synthesis.
