Bacteria Mitochondria

A well-known example of active transport is the sodium-potassium pump that maintains the imbalance of Na and ions across cytoplasmic membranes. Flere, the movement of ions is coupled to the hydrolysis of ATP to ADP and phosphate by the ATPase enzyme, liberating three Na+ out of the cell and pumping in two K [21-23]. Bacteria, mitochondria, and chloroplasts have a similar ion-driven uptake mechanism, but it works in reverse. Instead of ATP hydrolysis driving ion transport, H gradients across the membranes generate the synthesis of ATP from ADP and phosphate [24-27]. 

We shall see that the photosynthesis becomes isolated in plant chemotypes using derivatives of photosynthesising bacteria, chloroplasts, while degradation will be found in plants (no light), fungi and animals using derivatives of non-photosynthesising bacteria, mitochondria. These are cases of symbiosis. 

Volume 125. Biomembranes (Part M Transport in Bacteria, Mitochondria, and Chloroplasts General Approaches and Transport Systems)... 

Cytochromes b, a, and o. Protoheme-containing cytochromes b are widely distributed.127,128 There are at least five of them in E. coli. Whether in bacteria, mitochondria, or chloroplasts, the cytochromes b function within electron transport chains, often gathering electrons from dehydrogenases and passing them on to c-type cytochromes or to iron-sulfur proteins. Most cytochromes b are bound to or embedded within membranes of bacteria, mitochondria, chloroplasts, or endoplasmic reticulum (ER). For example, cyto-... 

An H+ electrochemical gradient (ApH+) provides the energy required for active transport of all classical neurotransmitters into synaptic vesicles. The Mg2+-dependent vacuolar-type H+-ATPase (V-ATPase) that produces this gradient resides on internal membranes of the secretory pathway, in particular endosomes and lysosomes (vacuole in yeast) as well as secretory vesicles (Figure 3). In terms of both structure and function, this pump resembles the F-type ATPases of bacteria, mitochondria and chloroplasts, and differs from the P-type ATPases expressed at the plasma membrane of mammalian cells (e.g., the Na+/K+-, gastric H+/K+-and muscle Ca2+-ATPases) (Forgac, 1989 Nelson, 1992). The vacuolar and F0F1... 

A FIGURE 8-2 Membrane orientation and the direction of proton movement during chemiosmotically coupled ATP synthesis in bacteria, mitochondria, and chloroplasts. The... 

A second very important eukaryotic organelle is the mitochondrion, which, like the nucleus, has a double membrane (Figure 1.13). The outer membrane has a fairly smooth surface, but the inner membrane exhibits many folds called cristae. The space within the inner membrane is called the matrix. Oxidation processes that occur in mitochondria yield energy for the cell. Most of the enzymes responsible for these important reactions are associated with the inner mitochondrial membrane. Other enzymes needed for oxidation reactions, as well as DNA that differs from that found in the nucleus, are found in the internal mitochondrial matrix. Mitochondria also contain ribosomes similar to those found in bacteria. Mitochondria are approximately the size of many bacteria, typically about 1 pm in diameter and 2 to 8 pm in length. In theory, they may have arisen from the absorption of aerobic bacteria by larger host cells. 

Mitochondria, the energy generators-and-storers of the living cell, are present in all cells except bacteria. Mitochondria, which are the site of all oxidative phosphorylation, form rods or nearly spherical cylinders, from 0.2 to 3.0 im in diameter. Often as many as a thousand mitochondria are present in a cell. 

The chaperonins are defined as a group of sequence-related molecular chaperones found in all bacteria, mitochondria and plastids (4). Table 2 lists some of the properties of the chaperonins. They are all abundant constitutive proteins that increase in amount after heat shock. In the case of E.coli and S.cerevisiae they are essential for cell viability at all temperatures. The bacterial chaperonins are major immunogens in human bacterial diseases because of their accumulation during the stress of infection. 

Class I Bacteria, mitochondria NAD(P)H EdR Fdx - P450 Pseudomonas putida CYPlOl (P450cam) [162, 163] Mammalian CYPllAl (P450ssc) [164]... 

In his chemiosmotic theory [52,53] Mitchell proposes that energy derived from respiratory activity, or from substrate level oxidation ( anaerobic metabolism) produces an electrochemical potential ( protonmotive force ) across the cell membrane of bacteria, mitochondria, and chloroplasts. The total protonmotive force is made up from two components an electrical potential gradient and a chemical gradient of protons (i.e. a pH gradient) across the membrane. The protonmotive force provides the energy for the active transport of sugars and amino... 

Mitochondria have membranes but no cell nucleus. Their size is that of small bacteria. Mitochondria generate most of the supply of ATP (Figure 11.2). There may be hundreds of mitochondria in a cell. Each mitochondrion is a subcell within the cell and contains two membranes. The inner membrane is wrinkled to increase its surface area. The inner compartment of the mitochondria is called the matrix and contains a concentrated aqueous solution of enzymes and other molecules. The inner membrane contains trapped membrane proteins (Figure 11.1) where cell respiration and photosynthesis take place. Here, ET and PT reactions and photosynthetic reactions take place. 

ATP synthase Membrane protein in bacteria, mitochondria, and plasmids that uses protons to make ATP for energy also called Complex V. 

Fq-Fj ATP-synthase of bacteria, mitochondria and chloroplasts, as discussed by the following arguments. 

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