Biomaterial Database

Pteridines and the function of the photosynthetic reaction center. 1969

R C Fuller, and N A Nugent

The photoreduction and interaction with the photosynthetic "reaction center" of 2-amino,4-hydroxy-6-substituted pteridine indicates that these low-potential ( approximately -0.7 v), naturally occurring compounds play a primary role in photosynthetic electron transport. These unconjugated pteridines, which occur in association with the photosynthetic apparatus of green plants and photosynthetic bacteria, can be reduced by light in the presence of a bacterial chromatophore fraction from the dihydro form to the tetrahydro form. 6,7-Dimethyl-tetrahydropteridine readily reduces spinach ferredoxin. This compound also specifically interacts with reaction-center chlorophyll and bacteriochlorophyll and produces spectral shifts similar to those produced by light. It is proposed that the electron produced by excited-state chlorophyll is captured and separated by a pteridine at -0.67 v at the photosynthetic reaction center.

UI	MeSH Term	Description	Entries
D010788	Photosynthesis	The synthesis by organisms of organic chemical compounds, especially carbohydrates, from carbon dioxide using energy obtained from light rather than from the oxidation of chemical compounds. Photosynthesis comprises two separate processes: the light reactions and the dark reactions. In higher plants; GREEN ALGAE; and CYANOBACTERIA; NADPH and ATP formed by the light reactions drive the dark reactions which result in the fixation of carbon dioxide. (from Oxford Dictionary of Biochemistry and Molecular Biology, 2001)	Calvin Cycle,Calvin-Benson Cycle,Calvin-Benson-Bassham Cycle,Carbon Fixation, Photosynthetic,Reductive Pentose Phosphate Cycle,Dark Reactions of Photosynthesis,Calvin Benson Bassham Cycle,Calvin Benson Cycle,Cycle, Calvin,Cycle, Calvin-Benson,Cycle, Calvin-Benson-Bassham,Photosynthesis Dark Reaction,Photosynthesis Dark Reactions,Photosynthetic Carbon Fixation
D010945	Plants, Edible	An organism of the vegetable kingdom suitable by nature for use as a food, especially by human beings. Not all parts of any given plant are edible but all parts of edible plants have been known to figure as raw or cooked food: leaves, roots, tubers, stems, seeds, buds, fruits, and flowers. The most commonly edible parts of plants are FRUIT, usually sweet, fleshy, and succulent. Most edible plants are commonly cultivated for their nutritional value and are referred to as VEGETABLES.	Food Plants,Edible Plant,Edible Plants,Food Plant,Plant, Edible,Plant, Food,Plants, Food
D011621	Pteridines	Compounds based on pyrazino[2,3-d]pyrimidine which is a pyrimidine fused to a pyrazine, containing four NITROGEN atoms.	1,3,5,8-Tetraazanaphthalene,Pteridine,Pteridinone,Pyrazino(2,3-d)pyrimidine,Pyrazinopyrimidine,Pyrazinopyrimidines,Pyrimido(4,5-b)pyrazine,Pteridinones
D002736	Chloroplasts	Plant cell inclusion bodies that contain the photosynthetic pigment CHLOROPHYLL, which is associated with the membrane of THYLAKOIDS. Chloroplasts occur in cells of leaves and young stems of plants. They are also found in some forms of PHYTOPLANKTON such as HAPTOPHYTA; DINOFLAGELLATES; DIATOMS; and CRYPTOPHYTA.	Chloroplast,Etioplasts,Etioplast
D004579	Electron Transport	The process by which ELECTRONS are transported from a reduced substrate to molecular OXYGEN. (From Bennington, Saunders Dictionary and Encyclopedia of Laboratory Medicine and Technology, 1984, p270)	Respiratory Chain,Chain, Respiratory,Chains, Respiratory,Respiratory Chains,Transport, Electron
D005055	Euglena	A genus of EUKARYOTES, in the phylum EUGLENIDA, found mostly in stagnant water. Characteristics include a pellicle usually marked by spiral or longitudinal striations.	Euglenas