Presentation on the mitosis in cell cycle

Presentation on the topic of mitosis

1. EISHA HEJAB 1607-BS-Z-21 Semester 5 Department of zoology Government college university lahore Mitochondria with reference to its role in cellular respiration and its significance as semi- autonomous organelle

2. Table of content: Mitochondria History Structure Power house of cell Role in cellular respiration Steps Semi- autonomous organelle Replication Importance Conclusion

3. mitochondria Mitochondria is a double membranous cytoplasmic organelle which plasma membrane contain enzyme for metabolism. It is present in aerobic cell (for aerobic cellular respiration to produce energy molecules )of higher living bodies It is also present in microorganism like protozoa, algae and fungi but absent in bacteria.

4. History: This granular organelle was first discover by Albert von Kölliker in 1850 from striated muscles. At first it was called as “fila” named by flemming in 1882. Richard Altman named this organelle as “bioblast”. In 1897Carl benda gave Current name to this organelle “mitochondria”. Location: Mitochondria is present randomly in cytoplasm of cell which shows uniform pattern of distribution but in some cells its arrangement and distribution is restricted. The number totally depend on the function of cell.

5. Morphology: Normally mitochondria is seen in the size of 0.5 to 2.0 micrometer. Mitochondria is consist of two specialized membrane of 6 nm in thickness like other membranes it also shows fluid mosaic in ultra- structure. The outer membrane contains a multiples of transport protein called porin . Transport protein makes aqueous channels throw the lipid bi layer. This give permeable property to mitochondrial outer membrane .it allows molecule of 10 thousand or less Daltons which also include small protein . The inner membrane is highly convoluted ,impermeable ,and rough in structure It has series of inners foldings which make a structure called cristae. Inner membrane separate mitochondrial space and the region between outer membrane and inner membrane is inter membrane space .

6. Double membrane :

7. Composition: It contain lipid, proteins, circular DNA molecule that makes it a self-replicating organelle. It also has 55 S ribosome(mammalian) and prominent granules. The inner membrane has two faces .C face which is towards mitochondrial space and M face towards matrics. Small particles are repeated on M face of inner membrane .these particle are F0-F1 particles .they play an important in phosphorylation and act as a ATP synthesis .these particles are distributed on the distance of 10 nm on inner surface

8. Power house of the cell: Our body is made up of trillions of cells. They require energy to perform normal function . this energy packets are created within cell(in mitochondria). Almost all aerobic cell carry out cellular respiration during this process organisms breakdown food(glucose) in order to produce energy (ATP). Majority of the reaction of cellular respiration occur in mitochondria of the cell .ATP is generated(all reaction carried out)at the inner membrane of mitochondria by “oxysomes”(elementary particles) through the mechanism called OXIDATIVE phosphorylation with the help of membrane proteins. in the inner membrane embedded part of oxysome is F0 while, from the inner membrane foldings, its head(F1) face toward the matrix is basically act as ATP synthase (ADP+Pi).

9. Steps of cellular respiration: Glycolysis citric acid cycle electron transport chain Glycolysis The first is step glycolysis occur in cytoplasm outside of the mitochondrial body . one glucose molecule into 2 pyruvate molecule .During this process we have net gain of 2 ATP and NADH molecule release which will be in use future in later step of cellular respiration .

10. Glycolysis:

11. Inside mitochondria: the product of glycolysis , pyruvate molecule enter in the mitochondrial matrix and converted into acetyl CoA during this conversion process more NADH is produce and carbon dioxide is produce by the waste product . Krebs cycle ( citric acid cycle) Third step is citric acid cycle here the remaining carbons from initials glucose is oxidize and realize carbon dioxide . This is eight step process involving specific(8) enzymes. The enzymes essential for krebs cycle in mitochondria are present in“mitochondrial matrix”. While succinate dehydrogenase is located in inner membrane .

12. Citric acid cycle:

13. Electron transport chain: The final stage of this respiration is electron transport chain where the major ATP production occur. In this stage NADH,FADH2from the previous cycle give up electron to the chain energy is release and capture as the electron move from a higher energy to a lower energy stage using a series of protein embedded in the inner membrane of mitochondria which are known as protein complexes 1to 4 . From one molecule of glucose 36-38 ATP molecule is a net gain in cellular respiration.

14. ETC:

15. Semi-autonomous organelle: There are some organelle who has their own genetic material(nucleic acid) and ribosome. Its mean they are independent and can produce their own mRNA that undergoes translation of that particular sequence to produce protein. They can control their own working. but consider as semi because they are not capable to produce their outer membrane and mitochondrial protein. So they rely on cell’s nucleus for maintenance and some other function .

16. Replication: Nucleic acid of mitochondria is similar to the bacteria , double stranded circular DNA not surrounded by any membrane. Mt DNA is quite small ,simple in structure.

17. Significance: Due to these properties it can perform all step transcription , translation, dna replication which is essential of gene expression . Mitochondria can also synthesis its own protein for instance; molecule essential in ETC cytochrome b, c1 complex, subunits of ATPsynthase. So mitochondria can regulate its function and can also act as “self replicating organelle”that can divide by binary fission just like of bacteria. It is approval of “endo-symbiont hypothesis”

18. Conclusion: Cell having large number of mitochondria which is possible by binary fission , can cause higher production of energy currency ATP. The energy that is the limiting factor of all the cell. It may suppress the function , whole working of cell by its malfunction or affected ATP production.