Introduction to Molecular Cell Biology Unit of Life

1. Introduction to Molecular Cell BiologyUnit of Life Dr. Fridoon Jawad Ahmad HEC Foreign Professor King Edward Medical University Visiting Professor LUMS-SSE

2. Overview

3. Life Life is not a random collection of some macromoleulces. Life is a collection of macromoleulces that can perform unique functions because the are enclosed in structural acompartment that provides consistency (homeostasis). All organisms are composed of cells the basic unit of life and all cells come from preexisting cells

4. Cells are Small Cells are small to maintain large surface area to volume ratio. Larger volume requires a grater exchange of materials from out side which is a function of surface area.

5. Prokaryotic Cells No membrane enclosed internal compartments. The plasma membrane regulates traffic is a barrier. Nucleoid region contains DNA, most have cell wall. Support & Cell shape Protection From Phagocytes

6. Special Prokaryotic Cells Cyanobacteria Chlorophyll containing have folds of plasma membrane, other have mesosomes (energy). Some have actin like filaments and other have Flagella made-up of Flagellin.

7. Eukaryotic Animal Cell

8. Eukaryotic Plant Cell

9. How the Function of Organelles was determined

10. The Nucleus

11. Chromatin and Chromosome

12. Ribosomes Free or attached to ER involved in protein synthesis. Present in Mitochondria & Chloroplasts. Contain protein and RNA.

13. RER Segregates newly synthesized Proteins. Chemically modifies proteins (Glycosylation adress)

14. SER Glycogen hydrolysis. Secreting and detoxifying cells have abundant SER Cis, Medial & Tarns

15. Golgi Apparatus The Golgi apparatus receives materials from the rough ER and modifies them. Concentrates sorts and packages proteins and sends them to other destinations. Manufactures poly-saccharides for the plant wall.

16. Lysosomes Lysosomes contain many digestive enzymes. Lysosomes fuse with the phagosomes produced by phagocytosis (autophagy) to form secondary lysosomes, where engulfed materials are digested. Undigested materials are secreted from the cell when the secondary lysosome fuses with the plasma membrane..

17. Mitochondria Breakdown fuel molecules to make ATP. Some protists have one, liver more than a thousan and egg a few hundred thousand MT. Mitochondria and chloroplasts contain their own DNA and ribosomes for making some of their own proteins.

18. Endosymbiosis The endosymbiosis theory of the evolutionary origin of mitochondria and chloroplasts states that these organelles originated when larger prokaryotes engulfed, but did not digest, smaller prokaryotes. Mutual benefits permitted this symbiotic relationship to be maintained, allowing the smaller cells to evolve into the eukaryotic organelles observed today. Photosynthesis Detoxification of O2

19. Peroxisomes and Glyoxysomes Peroxisomes collect and degrade toxic Peroxide H2 O2 byproducts of chemical reactions Glyoxysomes convert stored lipids into carbohydrates.

20. Cytoskeleton

21. Cytoskeleton Actin (cortical) Stabilizes cell shape. Generates movement local general. Constriction ring in cell divission (Cytokinesis). Movement of cytoplasam (cytoplasmic strreaming). IF stabilize cell structure (hold organelles). Stabilize and maintain tissue rigidity (desmosomes). Lamins in nucleus. Resist tention.

22. IF in Desmosomes

23. Microfilaments for Support

24. Celia are Made of Microtubules

25. movements The movements of cilia and flagella result from the binding of the motor protein dynein to the microtubules. Dynein and another motor protein, kinesin, also bind to microtubules to move organelles through the cell.

26. ECM in Animals Bone