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Flashcards in Metabolic Diversity Deck (45)
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1

What are the types of oxygen requirements?

- aerobes: require O2 for growth
- anaerobes: O2 not required for growth
- facultative aerobe: O2 is not required but it does enhance growth

2

What are the options for energy sources?

chemicals or light

3

What are the options for e- sources?

organic or inorganic compounds

4

What are the options for carbon sources?

organic or inorganic

5

Where do phototrophs get their energy from?

light

6

Where do chemoorganotrophs get their energy from?

organic chemicals

7

Where do chemolithotrophs get their energy from?

inorganic chemicals

8

Where do heterotrophs get their carbon from?

organic compounds

9

Where do autotrophs get their carbon from?

CO2 (inorganic)

10

What is the formula for sulphur respiration and who uses it?

HS- to S0
facultative aerobes and obligate anaerobes

11

What is the formula for sulphate respiration/reduction and who uses it?

HS- to (SO3)2-
obligate anaerobes

12

What is the formula for nitrate respiration and who uses it?

NO2- to NO3-
facultative aerobes

13

What is the formula for denitrification and who uses it?

N2 to NO3-
facultative aerobes

14

Denitrifying bacteria use ___ sources of energy/C/e-

organic

15

Denitrifying bacteria: N compounds are common ___ (anaerobic), N2/NO/N2O are gasses that are commonly ___ (this is ___ for agriculture and ___ for sewage treatment)

final e- acceptor/lost/bad/good

16

What are the two steps of denitrifying?

1. nitrate reduction (NO3-->NO2) ex. E. coli using nitrate reductase
2. denitrifying: NO3-->NO2 (nitrate reductase) --> NO --> N2O --> N2

17

What is the energy/C/e- source for sulphate and sulphur reduction?

organic compounds

18

Bacteria can use ___ or ___ as e- acceptors and can use either organic or inorganic compounds for ___, it uses ___ as the terminal e- acceptor and ___ as the e- donor

(SO4)2/(SO3)2/e- donor/S0/acetate or ethanol or organic compounds

19

What is responsible for the rotten egg smell and is the end product of sulphur reduction?

H2S

20

True or false: in phototrophs the light sensitive pigments have diverse absorption spectrums

true

21

Define the reaction centre

the small fraction of pigments in the photo complexes formed by bacteriophyll/chlorophyll and PRO that participate directly in photosynthesis

22

pigments surrounding the reaction centre act as ___ to ___ and ___ to the reaction centre

antennae/harvest light/funnel energy

23

Describe carotenoids:

hydrophobic, light-sensitive pigments embedded in the photosynthetic membrane, their primary role is to protect from light damage

24

What are phycobilins?

they form complexes with PRO that are the main light harvesting system in cyanobacteria and harvest light from different wavelengths than chlorophyll

25

Where does photosynthesis happen in eukaryotes?

A pmf is generated across the thylakoid membrane (in the chloroplast)

26

The stroma is ___ and the thylakoid space is ___

alkaline and negative/acid and positive

27

Where does photosynthesis happen in bacteria?

the pigments are integrated int the internal membranes (heliobacteria=cytoplasmic membrane, purple bacteria=intracytoplasmic membrane, cyanobacteria/prochlorophytes=thylakoid membrane)

28

What are chlorosomes?

Present in green sulphur and non-sulphur bacteria, they are large antennae networks of bacteriophylls (c, d, and e) that transfer energy to the reaction centre ( bacteriophyll a)

29

What is the best system to capture light in low light environments?

Chlorosome

30

Describe anoxygenic photosynthesis in purple bacteria

- H+ accumulates in the periplasm/vesicles/intracytoplasmic membrane
- cytoplasm is -
- light enters LH II and LH I and transports the electrons through the system
- NADH is made by reverse e- flow (e- go from C2 to C1 to reduce NAD)
- very low yield

31

Describe an oxygenic photosynthesis in green bacteria

- cyclic phosphorylation: no need for e- donor because e the e- cycle and create a pmf
- reducing power=needs an e- donor for NAD->NADH (ferredoxin), oxidation of reduced S compounds is an e- source
- two parallel systems: pmf->ATP and NAD->NADH

32

Describe oxygenic phosphorylation

H2O->O2+2H+2e-, e- ->e- chain->NADPH (creates pmf->ATP)
- noncyclic phosphorylation: pair of e- is used to produce pmf and NADPH
- when reducing power is enough for cell needs e- return to cyt bf because there is no need for additional e- source (cyclic)

33

In some cyanobacteria, H2S ___ PSII so ___ H2S becomes the main source of ___ which makes the e- chain become ___.
e- from ___ -> e- chain that creates ___
e- from ___ -> e- chain->NADPH

inhibits/oxidized/e-/anoxygenic
P700
H2S

34

What are chemoautotrophs?

- primary producers
- inorganic energy/e-/C source

35

What classification do nitrifying bacteria and sulphur bacteria fall under?

Chemoautotrophs

36

Nitrifying bacteria use ___ as e- donor

inorganic N compounds

37

What do the two groups of nitrifying bacteria do and what is the total result?

1. HN3->NO3 (ox)
2. NO2->NO3 (ox)
=NH3->NO3 (nitrification)

38

Is nitrification aerobic or anaerobic?

aerobic

39

For nitrosomonas: ___ is the final e- acceptor, 2e- are supplied by ___ which allows AMO to ___ NH3. NADH is produced by ___ (pmf energy source).

O2/Q/oxidize/reverse e- flow

40

For nitrobacter: ___ is the final e- acceptor, NXR=___, NADH produced by ___ with pmf energy source

O2/nitrite reductase/reverse e- flow

41

What do sulphur bacteria do?

- oxidize S compounds
- O2 is final e- acceptor
- produces SO4 and protons

42

What do methanogens do? What is the formula?

produce CH4 anaerobic
4H + CO2 -> CH4 + 2H2O + energy/ CH3COOH->CH4+CO2+energy

43

What do methanotrophs do? What is the formula?

use CH4 as an energy source aerobically
CH4->CH3OH->CH2O->HCOO->CO2

44

Where is CO2/Calvin cycle?

photoautotrophs (algae, cyanobacteria, purple sulphur bacteria, green sulphur bacteria), chemoautotrophs (nitrifying bacteria, sulphur bacteria, some methanogens), eukaryotes (in stroma), prokaryotes (in chloroplasts)

45

What is the net reaction for the Calvin cycle?

6CO2 + 12NADPH + 18ATP -> C6H12O6(PO3H2) + 12NADP + 18ADP + 17Pi