Exam 13: Phototrophy, Chemolithotrophy, and Major Biosyntheses

In photosynthesis, light energy is conserved as chemical energy.

Photooxidation reactions can lead to the production of toxic forms of oxygen and the destruction of the photosynthetic apparatus.

Light- mediated ATP synthesis in phototrophic organisms involves electron transport through a sequence of electron carriers.

Some hydrogen bacteria have a soluble (cytoplasmic) as well as a membrane- integrated hydrogenase that each serves different functions.

Photosystem I is responsible for splitting a water molecule in the first step of oxygenic electron flow.

RubisCO converts ribulose bisphosphate and CO₂ into two molecules of 3- phosphoglyceric acid (PGA).

In which microorganisms are phycobilins present?

Electron donors for chemolithotrophs may be geological, biological, or anthropogenic.

What is a quinine pool?

Illustrate the reaction center of a purple bacterium with the following features highlighted: antenna pigments, the special pair, protein H, protein L, protein M, and quinones. Also explain the importance of proximity for these components within a reaction center.

The only organisms that perform photosynthesis are ones that produce some form of

Most iron- oxidizing bacteria are obligate acidophiles.

Light energy is used to oxidize CO2 to form organic compounds.

The hydroxypropionate pathway may have been nature's first attempt at autotrophy in anoxygenic phototrophs.

In what types of organisms are carboxysomes found and what advantage do they provide for a cell?

Organisms grown with CO2 as its sole carbon source must have energy in the form of ATP as well as reducing power.

The system that oxidizes reduced sulfur compounds directly to sulfate without the intermediate formation of sulfite is known as _________.

The FeS electron acceptor proteins of the green bacteria and the heliobacteria have a much more electronegative E0' than NADH.

When elemental sulfur is provided externally as an electron donor, the organism must attach itself to the sulfur particle because of the extreme insolubility of elemental sulfur.

Oxygenic phototrophs use light to generate