Electron-transporting organelles

Tsukita, S. and Ishikawa, H. The movement of membranous organelles in axons. Electron microscopic identification of anterogradely and retrogradely transported organelles. /. Cell Biol. 84 513-530,1980. 

Mitochondria, which are cytoplasmic organelles involved in cellular respiration, have their own chromosome, which contains 16,569 DNA base pairs (bp) arranged in a drcalar molecule. This DNA encodes 13 proteins that are subunits of complexes in the electron transport and oxidative phosphorylation processes (see Section 1, Chapter 13). In addition, mitochondrial DNA encodes 22 transfer RNAs and two ribosomal RNAs. 

The metabolic machinery responsible for the heterotrophic respiration reactions is contained in specialized organelles called mitochondria. These reactions occur in three stages (1) glycolysis, (2) the Krebs or tricarboxylic acid cycle, and (3) the process of oxidative phosphorylation also known as the electron transport chain. As illustrated in... 

Mitochondria are subcellular organelles that are energy-generating machines. The electron transport chain is key to ATP generation in mitochondria. 

How complex can the proteome of hydrogenosomes in T. vaginalis be expected to be Trichomonad hydrogenosomes have lost many standard metabolic capacities of mitochondria like—and consequently most of the proteins involved in—the tricarboxylic cycle, membrane-bound electron transport and ATP-production (Muller 1993), or fatty acid synthesis (Beach et al. 1990). Because of the absence of a genome (Clemens and Johnson 2000) the complex machineries of DNA replication and repair, gene transcription and protein synthesis are also absent from these organelles. On the other hand, experimental evidence exists for only a small number of metabolic... 

Nasirudeen AM, Tan KS (2004) Isolation and characterization of the mitochondrion-like organelle from Blastocystis hominis.J Microbiol Methods 58 101-109 Painter HJ, Morrisey JM, Mather MW, Vaidya AB (2007) Specific role of mitochondrial electron transport in blood-stage Plasmodium falciparum. Nature 446 88-91 Perkins GA, Song JY, Tarsa L, Deerinck TJ, Ellisman MH, Frey TG (1998) Electron tomography of mitochondria from brown adipocytes reveals crista junctions. J Bioeneerg Biomembr 30 431-432... 

Photosynthesis occurs in the plant cell organelle called the chloroplast. During the process of photosynthesis, electrons are transferred from H20 to NADP+ via an electron carrier system. The energy released by electron transport is converted into the form of a proton gradient and coupled to ADP phosphorylation. In this experiment a method is introduced to demonstrate the formation of the proton gradient across the chloroplast membranes. 

Many of the biochemical processes that generate chemical energy for the cell take place in the mitochondria. These organelles contain the biochemical equipment necessary for fatty acid oxidation, di- and tricarboxylic acid oxidation, amino acid oxidation, electron transport, and ATP generation. In this experiment, a mitochondrial fraction will be isolated from beef heart muscle. The mitochondria will be analyzed for protein content and fractionated into submitochondrial particles. Each fraction will be analyzed for malate dehydrogenase and monoamine oxidase activities. 

CORR applies equally to mitochondria and chloroplasts, and accounts for the fact that both of these organelles possess membrane-intrinsic electron transport systems along with discrete, extranuclear genetic systems. CORR rests on ten assumptions, or principles, as follows ... 

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