Photosynthetic bacteria

Question 1

2 types of photosynthesis in bacteria

Answer 1

Oxygenic photosynthesis

Anoxygenic photosynthesis

Question 2

What happens in oxygenic photosynthesis

Answer 2

Have photosystems I and II
Electron donor = water
Produce O2

Question 3

What happens in Anoxygenic photosynthesis

Answer 3

Only 1 photosystem
Only perform cyclic photophosphorylation
Electron donor = reduced molecules (not H2O)
Do not produce O2

Question 4

Photosynthetic pigments in bacteria

Answer 4

Bacteriochlorophylls
chlorophylls
Accessory pigments

Question 5

chlorophylls

Answer 5

Narrow absorption spectra

Peaks at: 450-475 nm and 650-675 nm

Question 6

Bacteriochlorophylls

Answer 6

Broader absorption spectra:
Peaks between 350 and 550 nm
Peaks >750 nm (far-red spectrum)
Allow growth at greater depths

Question 7

Accessory pigments in bacteria

Answer 7

Phycobiliproteins

Carotenoids

Question 8

Unique structures of photosynthetic bacteria

Answer 8

Intracytoplasmic membrane

Chlorosomes (not chromosome)

Question 9

Intracytoplasmic membrane of photosynthetic bacteria

Answer 9

In-folding of cytoplasmic membrane to increase surface area

Location of pigments, reaction center, ETC (i.e., photosynthetic apparatus)

Question 10

Chlorosomes (not chromosomes) of photosynthetic bacteria

Answer 10

• Vesicles of photosynthetic pigments attached to inner surface of cytoplasmic membrane by protein baseplate
• Found in some photosynthetic bacteria

Question 11

Electron flow in photosynthetic bacteria

Oxygenic photosynthesis

Answer 11

As seen in chloroplasts and cyanobacteria

Photosystems I and II

Question 12

Electron flow in photosynthetic  bacteria
Anoxygenic photosynthesis (phototrophy)

Answer 12

1 photosystem (cyclic photophosphorylation)
Do not oxidize H2O
Ways to generate reducing power

Question 13

Ways Anoxygenic photosynthesis (phototrophy) generates reducing power

Answer 13

-H2 donates electrons to NADP+ producing NADPH (requires hydrogenases)
-Reverse electron flow PMF “pushes” e- to NAD(P)+
-Electrons spontaneously flow from ETC to NAD+
e- replaced by environmental electron donors

Question 14

Photosynthetic electron transport in cyanobacteria takes place \_\_\_\_\_\_\_\_.
A) on the plasma membrane
B) in the chloroplast
C) in the cytoplasm
D) on the thylakoid membranes

Answer 14

D) on the thylakoid membranes

Question 15

All prokaryotic photosynthesizers are anoxygenic.

Answer 15

False

Question 16

Which of the following described roles attributed to accessory pigments such as carotenes and phycobiliproteins? (Check all that apply.)
A) These pigments absorb light in ranges not absorbed by chlorophylls and transfer the energy to chlorophylls.
B) These pigments extend the spectrum of wavelengths that will drive photosynthesis.
C) The accessory pigments are involved in maintaining the Calvin cycle.
D) Accessory pigments protect organisms from potentially damaging intense sunlight.

Answer 16

A) These pigments absorb light in ranges not absorbed by chlorophylls and transfer the energy to chlorophylls.
B) These pigments extend the spectrum of wavelengths that will drive photosynthesis.
D) Accessory pigments protect organisms from potentially damaging intense sunlight.