Mitochondrial structure

talk about shape size and mitochondrial structure

1. Mitochondrial structure Prepared by : Nada Ibrahim

2. Introduction Occur in all Eukaryotic cells. Involved in energy production. contain enzymes for citric-acid cycle Oxidative phosphoryation . Production of ATP from ADP.

3. Shape, distribution & numbers Very small organelles( 0.5 *1-2 µm) . Rod shape with hemispheroidal ends, Some are cup or filamentous shape. Vary from globular to threadlike or branched Long filaments , not spatial in arrangement. shape Higher plants Animals

4. Shape, distribution & numbers Cells with active processes , Near wall ingrowths or chloroplast . Free in the cytoplasm. Packed in rigid structures , such among the myofibrils of cardiac muscle tissue . Distribution

5. Shape, distribution & numbers Depends on what the cell needs to do. Flagellated protozoa or sperm , they are found around the base of the flagellum. Cardiac muscle , they surround the contractile parts. Hummingbird flight muscle is the richest sources of mitochondria. When energy is not enough , more mitochondria are created ,they grow, move , and combine with other mitochondria. Numbers Examples Surviving

6. structure Double membrane organelle. The double-membrane described as a large wrinkled bag packed inside of a smaller, unwrinkled bag. The two membranes create 3 compartments within the organelle differ in structure and function . The space between two membranes is called inter-membrane space . Compartments

7. structure The matrix which fills the space of inner mitochondrial membrane. The cristae space (formed by infoldings of the inner membrane) . Outer membrane Is a smooth simple phospholipid bilayer membrane. Ions, nutrient molecules, ATP , etc pass through outer membrane with ease.

8. Forming channels allow molecules of about 10 kilodaltons or less to freely diffuse. The amount of phospholipids is higher than integral proteins called porins . The mitochondrial outer membrane can associate with the (ER) membrane. The ER-mitochondria calcium signaling and the transfer of lipids between the ER and mitochondria. Outer membrane

9. The inner membrane has infoldings called the cristae . The cristae greatly increase the total surface area of the inner membrane for the complexes and proteins. Is freely permeable only to O 2 ,CO 2 ,H 2 O . Regulating transfer of metabolites across the membrane. It is made up of a large number of proteins than phospholipids that control producing ATP. Inner membrane

10. Inner membrane Highly complex structure, including the electron transport system , the ATP synthetase complex , and transport proteins . NADH dehydrogenase which accept protons carried by NADH from tricarboxylic acid cycle. Transmembrane proton channels important in ATP synthesis .

11. Mitochondrial Matrix Contains dissolved o 2 , h 2 o, co 2 , the recyclable intermediates that serve as energy shuttles. Diffusion is very slow due to folds cristae . Citric acid cycle reactions occurrence.

12. Mitochondrial Matrix Contain enzymes for the synthesis of ATP , ribosomes , tRNAs and the mitochondrial DNA . Matrix components can diffuse to inner membrane complexes and transport proteins within short time .

13. Mitochondrial development Human mitochondrial DNA sequence revealed 16,569  base pairs encoding 37 total genes: 22  tRNA, 2 rRNA, and 13  peptide genes. Has its own independent DNA which is similar to bacterial DNA . Posses the machinery to manufacture their own RNAs and proteins . Reproduce by fission like bacteria do. due to their independence from the nuclear DNA and similarities with bacteria.