第十四回中州一剑应无恙海.48.ppt

* * * CHAPTER 6 MITOCHONDRION AND CHLOROPLAST I. Mitochondrion Structure and distribution: Usually, mitochondrion is like a particle or rod and others composed of proteins (65-70%) and lipids (25-30%) at 0.5~1μm diameter and 1.5~3.0μm length. The mitochondria in the cells of pancreas can be 10~20μm at length called huge mitochondrion. The number of mitochondrion in a cell can be hundreds to thousands, and less in plant cell than in animal cell because of chloroplast. Some unicellular organism contains 500,000 mitochondria inside, but mammalian erythrocytes contain no any mitochondrion inside. Mitochondrion can migrate in cell along micro tube, and motorprotein supplies energy for that. 1. Outer membrane Outer membrane contains lipids (40%) and proteins (60%). There are the hydrophilic tunnels composed of porin that allows the molecules lighter than 5KD passed through. 2. Inner membrane Inner membrane contains more than 100 types of polypeptide with a low permeability. The electron transmission chain of oxidative phosphorylation is located in inner membrane. Cytochrome C reductase is the marker enzyme for inner membrane. Inner membrane can be pleated into inside to form cristae. The cristaes enlarge the area of inner membrane to 5 – 10 folds. Cristae can be two types of shape: lamella or tube. Elementary particles are located on cristae, and composed of head part (F1 conjugate factor) and elemantary part (F0 conjugate factor). F0 inserts into inner membrane. 3. Intermembrane space It is between inner membrane and outer membrane with 6-8nm width. Adenylate kinase is the marker enzyme for intermembrane space. Photo of mitochondrion Lamella critae Inner membrane Outer membrane Intermembrane space A model structure of mitochondrion Matrix 4. Matrix The area surrounded by cristae, intermembrane space and inner membrane. Excepting glycolysis (in plasma), other bio-oxidation reactions are carried out in mit