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One of the main functions of the chloroplast is its role in photosynthesis, the process by which light is transformed into chemical energy, to subsequently produce food in the form of sugars. Water (H 2 O) and carbon dioxide (CO 2) are used in photosynthesis, and sugar and oxygen (O 2) are made, using light energy.
Like mitochondria, chloroplasts have a double-membrane envelope, called the chloroplast envelope, but unlike mitochondria, chloroplasts also have internal membrane structures called thylakoids. Furthermore, one or two additional membranes may enclose chloroplasts in organisms that underwent secondary endosymbiosis , such as the euglenids and ...
The reaction center will drive photosynthesis by taking light and turning it into chemical energy [3] that can then be used by the chloroplast. [2] Two families of reaction centers in photosystems can be distinguished: type I reaction centers (such as photosystem I in chloroplasts and in green-sulfur bacteria) and type II reaction centers (such ...
The structure and function of cytochrome b 6 f (in chloroplasts) is very similar to cytochrome bc 1 (Complex III in mitochondria). Both are transmembrane structures that remove electrons from a mobile, lipid-soluble electron carrier (plastoquinone in chloroplasts; ubiquinone in mitochondria) and transfer them to a mobile, water-soluble electron ...
These include the amount of light available, the amount of leaf area a plant has to capture light (shading by other plants is a major limitation of photosynthesis), the rate at which carbon dioxide can be supplied to the chloroplasts to support photosynthesis, the availability of water, and the availability of suitable temperatures for carrying ...
Plastids function to store different components including starches, fats, and proteins. [9] All plastids are derived from proplastids, which are present in the meristematic regions of the plant. Proplastids and young chloroplasts typically divide by binary fission, but more mature chloroplasts also have this capacity.
Each photosystem II contains at least 99 cofactors: 35 chlorophyll a, 12 beta-carotene, two pheophytin, two plastoquinone, two heme, one bicarbonate, 20 lipids, the Mn 4 CaO 5 cluster (including two chloride ions), one non heme Fe 2+ and two putative Ca 2+ ions per monomer. [4] There are several crystal structures of photosystem II. [5]
Not only do all members inside each class share common ancestry, but the two classes also, by means of common structure, appear related. [2] [3] Cyanobacteria, the precursor to chloroplasts found in green plants, have both photosystems with both types of reaction centers. Combining the two systems allows for producing oxygen. [3]