Phototrophy – Flashcards

The metabolic diversity of photosynthetic bacteria stems from different

Whether an organism is classified as a photoheterotroph or a photoautotroph depends on its

In photosynthesis, NADH and NADPH are produced from NAD+ and NADP+ by

Bacteriochlorophyll and chlorophyll contain ________ as a cofactor.

The conversion of light into chemical energy is called photoautotrophy.

Reaction centers ONLY indirectly receive photon energy via light-harvesting molecules.

Chlorosomes are present in purple bacteria but absent in green sulfur and nonsulfur bacteria.

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

Which of the following types of organisms uses hydrogen sulfide for reducing power?

In which organism would you likely find a chlorosome?

Which of the following is a bacterium that performs oxygenic photosynthesis?

What is the key difference between photoheterotrophs and photoautotrophs?

Which of the following is a trait unique to photosynthetic eukaryotes?

Proteomic analysis of a microbial community indicated an abundance of phycobiliproteins. Which phototrophic group is likely active and abundant in this community?

At some of the lowest light concentrations, ________ can still grow well due to their ________, which effectively harvest photons for energy.

Each chlorophyll and bacteriochlorophyll type is distinguished by its absorption spectrum.

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

"Special pair" is the name given to the ________ in the photochemical complex of the purple bacteria.

The process by which electrons from the quinone pool are forced against the thermodynamic gradient to reduce NAD+ to NADH is called reverse

Phototrophic purple bacteria such as Rhodobacter species grow ONLY by photosynthesis, using bacteriochlorophylls to harvest light.

Two separate photosystems involved in electron flow is a hallmark of

What will happen to a cyanobacterium that has its photosystem II (PSII) blocked?

The path of electron flow in oxygenic phototrophs is referred to as the ________ scheme.

Plastocyanin is a

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

What is the role of water in cyclic photophosphorylation?

Where do the electrons from photosystem I ultimately go after they are passed through the electron transport proteins?

According to the animation, where would you find the lowest pH?

What drives the production of ATP in cyclic photophosphorylation?

Where does the energy to excite the electrons in photosystem I come from?

Noncyclic photophosphorylation employs which photosystem(s)?

What is the fate of electrons in noncyclic photophosphorylation?

What is the fate of the NADPH molecules created during noncyclic photophosphorylation?

What form of photosynthesis evolved first on Earth?

Phototrophic bacteria all share some common features. These shared features include __________.

The only group of oxygenic phototrophic bacteria are the

The Cyanobacteria are united by their ________, but their ________ is very diverse.

Differentiation in a cell that allows for nitrogen fixation during photosynthesis is termed __________.

Although Cyanobacteria contribute more than 35% of all photosynthesis on Earth, they are not visible in the natural environment.

Unicellular cyanobacteria are the most abundant phototrophs in the ocean and perform 80% of marine photosynthesis.

Purple sulfur bacteria are

Green sulfur bacteria are often found at the greatest depths of all phototrophic cells in lakes, oceans, and microbial mats. This is because green sulfur bacteria

The ecological diversity of phototrophic bacteria is illustrated by the different ________ that allow them to perform photosynthesis in low light environments such as deep in the ocean, in various sediments, and in thick layered mats.

All phototrophic bacteria use a monophyletic photosystem in photosynthesis, thus there is intense competition for light between different phototrophic bacteria.

Anoxygenic phototrophs

Aside from using light as a source of energy, another important part of the functional diversity of some bacterial phototrophs is their ability to

You are looking at a sample from the top green layer of a colorful bacterial mat. Using phase contrast and fluorescence microscopy, you see evenly spaced cells in the middle of a filament that are slightly smaller than the others. The smaller cells are not fluorescent, indicating they lack photosystem II, but the rest of the filament is fluorescent. What type of filamentous bacteria are you most likely looking at?

Anoxygenic phototrophs may or may not be autotrophs.