Biomaterial Database

Dual action of ionophore A23187 on intact chloroplasts. 1978

A Telfer, and J Barber

1. Ionophore A23187 induces uncoupling of potassium ferricyanide-dependent O2 evolution by envelope-free chloroplasts and oxaloacetate-dependent O2 evolution by intact chloroplasts. The half maximal concentration (C1/2) for stimulation of oxygen evolution in both cases is approximately 4 micrometer . 100 microgram chlorophyll . ml-1. 2. Ionophore A23187 also induces inhibition of CO2 and 3-phosphoglycerate-dependent O2 evolution by intact chloroplasts in the presence of 3 mM MgCl2. The half maximal concentrations (C1/2) for inhibition of O2 evolution are 3 micrometer and 5 micrometer respectively . 100 microgram-1 chlorophyll . ml-1. 3. A very high concentration of ionophore A23187 (10 microgram . 20 microgram-1 chlorophyll . ml-1) plus 0.1 mM EDTA lowers the fluorescence yield of intact chloroplasts suspended in a cation-free medium in the presence of 3-(3,4-dichlorophenyl)-1,1-dimethylurea, indicating loss of divalent cation from the diffuse double layers of the thylakoid membranes. 4. These results are discussed in relation to ionophore A23187-induced divalent cation/proton exchange at both the thylakoid and the envelope membranes of intact chloroplasts.

UI	MeSH Term	Description	Entries
D008027	Light	That portion of the electromagnetic spectrum in the visible, ultraviolet, and infrared range.	Light, Visible,Photoradiation,Radiation, Visible,Visible Radiation,Photoradiations,Radiations, Visible,Visible Light,Visible Radiations
D008274	Magnesium	A metallic element that has the atomic symbol Mg, atomic number 12, and atomic weight 24.31. It is important for the activity of many enzymes, especially those involved in OXIDATIVE PHOSPHORYLATION.
D010071	Oxaloacetates	Derivatives of OXALOACETIC ACID. Included under this heading are a broad variety of acid forms, salts, esters, and amides that include a 2-keto-1,4-carboxy aliphatic structure.	Ketosuccinates,Oxosuccinates,Oxaloacetic Acids
D010100	Oxygen	An element with atomic symbol O, atomic number 8, and atomic weight [15.99903; 15.99977]. It is the most abundant element on earth and essential for respiration.	Dioxygen,Oxygen-16,Oxygen 16
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
D002245	Carbon Dioxide	A colorless, odorless gas that can be formed by the body and is necessary for the respiration cycle of plants and animals.	Carbonic Anhydride,Anhydride, Carbonic,Dioxide, Carbon
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
D004237	Diuron	A pre-emergent herbicide.	DCMU,3-(3,4-Dichlorophenyl)-1,1-dimethylurea
D004492	Edetic Acid	A chelating agent that sequesters a variety of polyvalent cations such as CALCIUM. It is used in pharmaceutical manufacturing and as a food additive.	EDTA,Edathamil,Edetates,Ethylenediaminetetraacetic Acid,Tetracemate,Calcium Disodium Edetate,Calcium Disodium Versenate,Calcium Tetacine,Chelaton 3,Chromium EDTA,Copper EDTA,Coprin,Dicobalt EDTA,Disodium Calcitetracemate,Disodium EDTA,Disodium Ethylene Dinitrilotetraacetate,Distannous EDTA,Edetate Disodium Calcium,Edetic Acid, Calcium Salt,Edetic Acid, Calcium, Sodium Salt,Edetic Acid, Chromium Salt,Edetic Acid, Dipotassium Salt,Edetic Acid, Disodium Salt,Edetic Acid, Disodium Salt, Dihydrate,Edetic Acid, Disodium, Magnesium Salt,Edetic Acid, Disodium, Monopotassium Salt,Edetic Acid, Magnesium Salt,Edetic Acid, Monopotassium Salt,Edetic Acid, Monosodium Salt,Edetic Acid, Potassium Salt,Edetic Acid, Sodium Salt,Ethylene Dinitrilotetraacetate,Ethylenedinitrilotetraacetic Acid,Gallium EDTA,Magnesium Disodium EDTA,N,N'-1,2-Ethanediylbis(N-(carboxymethyl)glycine),Potassium EDTA,Stannous EDTA,Versenate,Versene,Acid, Edetic,Acid, Ethylenediaminetetraacetic,Acid, Ethylenedinitrilotetraacetic,Calcitetracemate, Disodium,Dinitrilotetraacetate, Disodium Ethylene,Dinitrilotetraacetate, Ethylene,Disodium Versenate, Calcium,EDTA, Chromium,EDTA, Copper,EDTA, Dicobalt,EDTA, Disodium,EDTA, Distannous,EDTA, Gallium,EDTA, Magnesium Disodium,EDTA, Potassium,EDTA, Stannous,Edetate, Calcium Disodium,Ethylene Dinitrilotetraacetate, Disodium,Tetacine, Calcium,Versenate, Calcium Disodium
D005994	Glycerophosphates	Any salt or ester of glycerophosphoric acid.	Glycerolphosphate,Glycerophosphate,Calcium Glycerophosphate,Glycerolphosphates,Glycerophosphate, Calcium