Question

Which is correct for bacteria?

• A. They have both cyclic and non-cyclic photo phosphorylation
• B. They absorb light > 900 nm of wavelength
• C. They release ${\text{O}}_{\text{2}}$ during photosynthesis
• D. They use ${\text{H}}_{\text{2}}\text{O}$ during photosynthesis

Answer 1

Answer: (B)

Photosynthetic bacteria contain bacterial chlorophyll as a light trapping pigment molecule that absorbs light between 800 to 925 nm, depending on the species of bacteria. Bacterial photosynthesis occurs without evolution of ${\text{O}}_2$ (it is anoxygenic process) as water $(H_{2}O)$ is not used as hydrogen donor. Instead of ${\text{H}}_{\text{2}}\text{,}{\text{H}}_{\text{2}}\text{S}$ and other similar compounds are employed as the electron donor. Bacteria have only one pigment system similar to that of $\text{PS}-\text{I}$ thus, only cyclic photophosphorylation occurs in hotosynthetic bacteria.