microchap14

A protein complex that harvests light from a chlorophyll, splits an electron from a small molecule such as H2S or H2O, and stores energy in the form of NADPH.

A protein complex that splits an electron from bacteriochlorophyll and stores energy in the form of a proton potential.

The use of a molecule other than oxygen as the final electron acceptor of an electron transport chain.

The anaerobic oxidation of ammonium to nitrogen gas (using nitrate as electron acceptor); yields energy.

A complex of chlorophylls and accessory pigments in the photosynthetic membrane that collects photons and funnels them to a reaction center.

The chlorophylls of anaerobic phototrophs; they absorb photons most strongly in the far red end of the light spectrum.

An archaeal membrane-embedded protein that contains retinal and acts as a light-driven proton pump; homologous to the bacterial proteorhodopsin.

Accessory photosynthetic pigments that absorb photons in the green end of the spectrum.

A magnesium-containing pigment that captures light energy at the start of photosynthesis.

A light-absorbing redox cofactor.

A photosynthetic process in which chlorophyll serves as both the initial electron donor and the final electron acceptor. ATP is produced via the proton potential from an electron transport system, but no NADPH is generated.

A membrane protein that donates and receives electrons.

The reduction of halogenated organic molecules by H2.

Metabolic reduction of nitrate or nitrite to yield energy; anaerobic respiration of nitrate or nitrite.

A type of anaerobic respiration that uses metal cations as terminal electron acceptors.

An oxidized molecule (e.g., NAD+) that can accept electrons.

A reduced molecule (e.g., NADH) that can donate electrons.

A collection of membrane proteins that converts the energy of redox reactions into a proton potential.

An iron- and sulfur-containing protein that transfers electrons in electron transport systems.

An organic molecule containing a ring of conjugated double bonds surrounding an iron atom. It is involved in redox reactions and oxygen binding.

The use of molecular hydrogen (H2) as an electron donor for a variety of electron acceptors.

The process of metal dissolution from ores.

Energy-yielding metabolism that uses an inorganic electron donor; usually includes fixation of CO2 into biomass.

The interior of an intracellular membrane-bound compartment.

An organism that uses hydrogen to reduce CO2 and other single-carbon compounds to methane, yielding energy.

An energy-yielding metabolic process that produces methane. It is unique to archaea.

The metabolic oxidation of methane to yield energy.

An organism that converts reduced nitrogen compounds to nitrite or nitrate.

An electron transport system protein that accepts electrons from one molecule (oxidizing that molecule), and donates electrons to a second molecule, thereby reducing the second molecule.

An ATP-producing photosynthetic pathway consisting of photosystems I and II. Water serves as the initial electron donor (generating O2) and NADP+ is the final electron acceptor, generating NADPH.

The production of energy by the photolysis of organic compounds.

The first energy-yielding phase of photosynthesis, the light-driven separation of an electron from a molecule coupled to an electron transport system.

The metabolic ability to absorb and convert solar energy into chemical energy for biosynthesis; a precise definition includes CO2 fixation.

Obtaining energy from chemical reactions triggered by the absorption of light.

A bacterial membrane protein that contains retinal and acts as a light-driven proton pump; homologous to the archaeal protein bacteriorhodopsin.

The potential energy of the concentration gradient of protons (hydrogen ions, H+) plus the charge difference across a membrane.

A reduced electron carrier that can diffuse laterally within membranes.

An oxidized electron carrier that can diffuse laterally within membranes.

The oxidized quinones and reduced quinols that diffuse freely within the phospholipid membrane and are able to transfer electrons between many different redox enzymes.

The chlorophyll molecule that donates its excited electron to an electron transport system.

The oxidized and reduced states of a compound. For example, NAD+ and NADH form a redox couple.

The oxidation of reduced electron donors through a series of membrane-embedded electron carriers to a final electron acceptor. The energy derived from the redox reactions is stored as an electrochemical gradient across the membrane, which may be harnessed to produce ATP.

A vitamin A related cofactor in opsin proteins; it undergoes a conformational change in response to photon absorption.

A standard value of E, at standard temperature and pressure and assuming initial 1 M concentrations of all reactants and products.

The compartment contained by the inner chloroplast membrane where the light-independent reactions of photosynthesis occur (CO2 fixation).

A chlorophyll-containing membrane folded within a phototrophic bacterium or a chloroplast.

A molecule that makes a membrane permeable to protons, dissipating the proton motive force and uncoupling electron transport from ATP synthesis.

A molecule that makes a membrane permeable to protons, dissipating the proton motive force and uncoupling electron transport from ATP synthesis.