Cristae membrane

Figure 9.1 Simple diagram of a mitochondrion showing inner and outer membranes, cristae and matrix.

The mitochondrial inner membrane, cristae, and matrix are the sites of most reactions involving the oxidation of pyruvate and fatty acids to CO2 and H2O and the coupled synthesis of ATP from ADP and Pj. These processes Involve many steps but can be subdivided into three groups of reactions, each of which occurs in a discrete membrane or space in the mitochondrion (Figure 8-7) ... 

Figure 12-1. Structure of the mitochondrial membranes. Note that the inner membrane contains many folds, or cristae.

This process occurs in the mitochondria, organelles present in the cells of all multicellular organisms (see Figs 6.8 and 6.26). Mitochondria have two membranes. The invaginations of the internal membrane into the inner space of the organelle (matrix space) are termed crests (from the Latin, cristae). 

Here we must introduce a complication in the structures of cellular compartments. We have treated the small bacterial cells as one aqueous phase, the cytoplasm, within one containing membrane. Now there are many examples of the membrane inside the wall as a very convoluted structure with cristae reaching far... 

Mitochondria are the centers for oxidative phosphorylation and the respiratory centers of all cells. While usually aerobic, some mitochondria (e.g. in some bacteria), are known that function anaerobically. These organelles occur ubiquitously in the neuron and its processes (Figs 1-4, 1-6). Their overall shape may change from one type of neuron to another but their basic morphology is identical to that in other cell types. Mitochondria consist morphologically of double-membraned sacs surrounded by protuberances, or cristae, extending from the inner membrane into the matrix space [7]. 

Mitochondria (45-56) are organelles possessing a double membrane, the inner of which is invaginated as cristae. An intermembrane space exists between the inner and outer membranes. The inner membrane consists of an unusually high amount of protein and possesses spherically shaped particles approx 9 nm in diameter. These particles appear to be equivalent to F0, Fb and adenosine triphosphatase. In contrast to the inner membrane, the outer membrane is smooth and appears to be connected to the smooth er. This membrane is permeable to all molecules of 10,000 Dalton or less. A mitochondrial matrix is enclosed by the inner membrane and consists of a ground substance of particles, nucleoids, ribosomes, and electron-transparent regions containing DNA. 

Mitochondria are distinct organelles with two membranes. The outer membrane limits the organelle and the inner membrane is thrown into folds or shelves that project inward and are called cristae mitochondriales. The uptake of most mitochondrion-selective dyes is dependent on the mitochondrial membrane potential. Conventional fluorescent stains for mitochondria, such as rhodamine and tetramethylrosamine, are readily sequestered by functioning mitochondria. They are, however, subsequently washed out of the cells once the mitochondrion s membrane potential is lost. This characteristic limits their use in experiments in which cells must be treated with aldehyde-based fixatives or other agents that affect the energetic state of the mitochondria. To overcome this limitation, the research... 

Figure 1.6 Nyctotherus ovalis (an anaerobic heterotrichous ciliate from the hindgut of an American Cockroach) hydrogenosome with mitochondrial-type cristae (white arrows) r putative ribosomes m membrane me methanogenic endosymbiont (methanogenic bacterium) (J.H.P. Hackstein, Catholic University of Nijmegen,The Netherlands).

All mitochondria have an outer membrane, which is permeable to small molecules, and an inner membrane, which is much less permeable and extensively folded to form cristae that extend into the matrix (Figure 1.3). 

Mitochondria are bacteria-sized organelles (about 1 X 2 im in size), which are found in large numbers in almost all eukaryotic cells. Typically, there are about 2000 mitochondria per cell, representing around 25% of the cell volume. Mitochondria are enclosed by two membranes—a smooth outer membrane and a markedly folded or tubular inner mitochondrial membrane, which has a large surface and encloses the matrix space. The folds of the inner membrane are known as cristae, and tube-like protrusions are called tubules. The intermembrane space is located between the inner and the outer membranes. 

In tomographic reconstructions of fixed sporozoites, a single, highly folded inner membrane (Fig. 2), or multiple internal subcompartments (see Figs. 12-15, Keithly et al. 2005), were visualized within the organelle. As mentioned before, the infoldings of the IM appeared to lack tubular crista... 

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