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Cell Biology_ Lec. (1).pdf cell biology introduction
- 1. CELL BIOLOGY Dr. JihadEl-Qassas (PhD)
- 2. Introduction of cellbiology ▪ Cell Biology: • Branch of biological science which deals with the study of structure, function, molecular organization, growth, reproduction and genetics of the cells. • Cell biology mainly concern with study of structure of cell and function of specialized cells.
- 3. Introduction of cellbiology ▪ History of cytology: • The term cell – Robert Hooke (1635-1703) the mid 17th century to describe the structure of cork. • Anton van Leeuwenhoek (1632-1723): 1st recorded observations of bacterial cells (termed “animalcules”) from pond water and tooth scrapings. • 1830s: the importance of cells realized. • 1838: German botanist Matthias Schleiden (1804-1881) observed that despite differences in tissue structure, all plants tissues were made of cells.
- 4. Introduction of cellbiology ▪ History of cytology: • The term cell – Robert Hooke (1635-1703) the mid 17th century to describe the structure of cork. Robert Hooke (the father of cytology)
- 5. Introduction of cellbiology ▪ History of cytology: • The term cell – Robert Hooke (1635-1703) the mid 17th century to describe the structure of cork. Robert Hooke (the father of cytology)
- 6. Introduction of cellbiology ▪ History of cytology: • The term cell – Robert Hooke (1635-1703) the mid 17th century to describe the structure of cork. • Anton van Leeuwenhoek (1632-1723): 1st recorded observations of bacterial cells (termed “animalcules”) from pond water and tooth scrapings. • 1830s: the importance of cells realized. • 1838: German botanist Matthias Schleiden (1804-1881) observed that despite differences in tissue structure, all plants tissues were made of cells.
- 7. Introduction of cellbiology ▪ History of cytology: • Anton van Leeuwenhoek (1632-1723): 1st recorded observations of bacterial cells (termed “animalcules”) from pond water and tooth scrapings. Anton van Leeuwenhoek and his hand lens
- 8. Introduction of cellbiology Anton van Leeuwenhoek and his hand lens • Microscopic observations by Anton van Leeuwenhoek
- 9. Introduction of cellbiology ▪ History of cytology: • The term cell – Robert Hooke (1635-1703) the mid 17th century to describe the structure of cork. • Anton van Leeuwenhoek (1632-1723): 1st recorded observations of bacterial cells (termed “animalcules”) from pond water and tooth scrapings. • 1830s: the importance of cells realized. • 1838: German botanist Matthias Schleiden (1804-1881) observed that despite differences in tissue structure, all plants tissues were made of cells.
- 10. Introduction of cellbiology ▪ History of cytology: • The term cell – Robert Hooke (1635-1703) the mid 17th century to describe the structure of cork. • Anton van Leeuwenhoek (1632-1723): 1st recorded observations of bacterial cells (termed “animalcules”) from pond water and tooth scrapings. • 1830s: the importance of cells realized. • 1838: German botanist Matthias Schleiden (1804-1881) observed that despite differences in tissue structure, all plants tissues were made of cells.
- 11. Introduction of cellbiology ▪ History of cytology: • 1838: German botanist Matthias Schleiden (1804-1881) observed that despite differences in tissue structure, all plants tissues were made of cells. Matthias Schleiden German botanist
- 12. Introduction of cellbiology ▪ History of cytology: • 1839 – German zoologist Theodor Schwann (1810-1882) realized animals were also composed of fundamental cellular units or cells. • Schwann proposed 1st 2 principles of cell theory: • All organisms consist of one or more cells. • The cell is the structure unit of life Theodor Schwann (1810-1882)
- 13. Introduction of cellbiology ▪ History of cytology: • Schleiden-Schwann realized could arise from non-cellular materials. • German physician Rudolf Virchow (1821-1902) demonstrated that living cells (biogenesis), and not from inanimate matter (abiogenesis). Rudolf Virchow (1821-1902)
- 14. Introduction of cellbiology What is the Cell Definition? ▪ The cell: is the smallest unit of life. ▪ The cell: is the basic structural, functional, and biological unit of all known organisms, except viruses.
- 15. Introduction of cellbiology ▪ What is the Cell? • The cells from latin cella, or cellula meaning “Small room”.
- 16. Introduction of cellbiology ▪ A.G. Loewry and P. Siekevitz (1963) have defined a cell as “a unit of biological activity delimited by a semi-permeable membrane and capable of self- reproduction in a medium free of other living systems”.
- 17. Introduction of cellbiology 1. Highly complex and organized. 2. Possess a genetic program and the means to use it. ▪ Properties of a Cell:
- 18. Introduction of cellbiology 3. Capable of producing more of themselves. 4. Capable of self-regulation. ▪ Properties of a Cell:
- 19. Introduction of cellbiology 5. Acquire and utilize energy. 6. Carry out a variety of chemical reactions. ▪ Properties of a Cell:
- 20. Introduction of cellbiology 7. Engage in mechanical activities. 8. Able to respond to stimuli. ▪ Properties of a Cell:
- 21. Introduction of cellbiology ▪ The cell is of two types: 1- Eukaryotic which are contain a nucleus. e.g. Plant & animal. 2- Prokaryotic which do not. e.g. Bacteria Cells Eukaryotic Plant Animal Prokaryotic Bacteria
- 22. Introduction of cellbiology ▪ The cell is of two types:
- 23. Introduction of cellbiology Prokaryotic Eukaryotic Size Small (1-10µm), unicellular. Large (10-100µm), multicellular. Cell membrane Single membrane and cell wall. Membrane bilayer. Nucleus No nucleus. Nucleus. DNA Circular DNA. Linear DNA. Histone No histones. Histones. Cell organelles No cell organelles. Membrane bond organelles. Ribosomes Free in cytoplasm. 50S +30S (70S). On surface of ER. 60S +40S (80S). Cell division Fission. By Mitosis. Cytoskeleton Absent, has flagella. Present. Examples Bacteria. Plants & Animals.
- 24. Introduction of cellbiology
- 25. Introduction of cellbiology ▪ The organisms can be classified as a unicellular (consisting of a single cell such as bacteria), or multicellular (including plants and animals) Amoeba sp
- 26. Introduction of cellbiology
- 27. Introduction of cellbiology
- 28. Introduction of cellbiology ▪ The organisms can be classified as a unicellular (consisting of a single cell such as bacteria), or multicellular (including plants and animals) Human
- 29. Introduction of cellbiology ▪ Cell consists mainly of two components (Protoplasm): 1. Centric nucleus. 2. Cytoplasm enclosed within a cell-membrane.
- 30. Introduction of cellbiology ▪ The protoplasm surrounded the nucleus is known as “Cytoplasm”, While that of the nucleus is known as “Karyoplasm”.
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- 32. Cell membrane ▪ Thinmembrane that surrounds every living cell, delimiting the cell from the environment around it. ▪ Cell membrane (also known as the plasma membrane). ▪ A phospholipid bilayer with proteins, Protein = 40% and lipid = 60%. ❖ Composition:
- 33. Cell membrane 1. Separatesthe interior of the cell from the outside environment. 2. It also provides a fixed environment inside the cell, and that membrane has several different functions. 3. Provides protection for a cell. 4. Also provides some structural support for a cell. ❖ Function:
- 34. Cell membrane 5. Thecell membrane regulates the transport of materials entering and exiting the cell. 6. One is to transport nutrients into the cell and also to transport toxic substances out of the cell. ❖ Function:
- 35. Cytoplasm ▪ Everything ina cell except the nucleus is cytoplasm. ▪ Clear, gelatin-like, watery substance surrounding the organelles. • Water = 90% • Organic and inorganic compounds = 10% ❖ Composition:
- 36. Cytoplasm 1. Maintains theshape and consistency of the cell. 2. Allows for chemical reactions necessary in metabolism. 3. Site for many metabolic pathway. Ex: glycolysis, protein synthesis, fatty acid synthesis, purine synthesis. ❖ Function:
- 37. Nucleus ▪ Nucleus, inbiology, a specialized structure occurring in most cells (except bacteria and blue-green algae). ▪ It separated from the rest of the cell by a double layer, the nuclear membrane. This membrane seems to be continuous with the endoplasmic reticulum (a membranous network) of the cell and has pores, which are probably permit the entrance of large molecules.
- 38. Nucleus 1. The nucleuscontrols and regulates the activities of the cell (e.g., growth and metabolism). 2. Carries the genes, structures that contain the hereditary information. 3. It primarily serves as the information center of the cell. ❖ Function:
- 39. Centrioles ▪ “Centriole isan organelle, cylindrical in shape, that is composed of a protein called tubulin.” ▪ They are usually present near the nucleus but are not visible when the cell is not dividing. ❖ Centriole Definition
- 40. Centrioles 1. In spiteof being devoid of DNA, the centrioles are capable of forming new centrioles. 2. They can be transformed into basal bodies, and the basal bodies give rise to flagella and cilia. 3. They help in cell division by forming microtubule organizing centers. 4. Out of the two centrioles, the distal centriole forms the tail or axial filament. ❖ Function:
- 41. Mitochondria ▪ Mitochondrion, membrane-boundorganelle found in the cytoplasm of almost all eukaryotic cells (cells with clearly defined nuclei). ▪ Mitochondria are typically round to oval in shape and range in size from 0.5 to 10 μm. ▪ Mitochondria are unlike other cellular organelles in that they have two distinct membranes and a unique genome. ▪ It reproduce by binary fission; these features indicate that mitochondria share an evolutionary past with prokaryotes (single-celled organisms).
- 42. Centrioles 1. The primaryfunction of which is to generate large quantities of energy in the form of adenosine triphosphate (ATP). 2. In addition to producing energy, mitochondria store calcium for cell signaling activities, generate heat, and mediate cell growth and death. ❖ Function:
- 43. Golgi apparatus ▪ Golgiapparatus, membrane-bound organelle of eukaryotic cells (cells with clearly defined nuclei) that is made up of a series of flattened, stacked pouches called cisternae. ▪ It is located in the cytoplasm next to the endoplasmic reticulum and near the cell nucleus.
- 44. Golgi apparatus ▪ Ingeneral, the Golgi apparatus is made up of approximately four to eight cisternae, although in some single-celled organisms it may consist of as many as 60 cisternae. ▪ The cisternae are held together by matrix proteins, and the whole of the Golgi apparatus is supported by cytoplasmic microtubules.
- 45. Golgi apparatus ▪ Thethree primary compartments of the apparatus are known generally as “cis” (cisternae nearest the endoplasmic reticulum), “medial” (central layers of cisternae), and “trans” (cisternae farthest from the endoplasmic reticulum). ▪ Two networks, the cis Golgi network and the trans Golgi network, which are made up of the outermost cisternae at the cis and trans faces, are responsible for the essential task of sorting proteins and lipids that are received (at the cis face) or released (at the trans face) by the organelle.
- 46. Golgi apparatus 1. Packagingand secretion of proteins. 2. It receives proteins from Endoplasmic Reticulum. It packages it into membrane-bound vesicles, which are then transported to various destinations, such as lysosomes, plasma membrane or secretion. 3. They also take part in the transport of lipids and the formation of lysosomes. 4. Post-translational modification and enzymatic processing occur near the membrane surface in Golgi bodies, e.g. phosphorylation, glycosylation, etc. 5. Golgi apparatus is the site for the synthesis of various glycolipids, sphingomyelin, etc. ❖ Function:
- 47. Endoplasmic Reticulum (ER) ▪Endoplasmic reticulum (ER), in biology, a continuous membrane system that forms a series of flattened sacs within the cytoplasm of eukaryotic cells. ▪ It serves particularly in the synthesis, folding, modification, and transport of proteins. ▪ Differences in certain physical and functional characteristics distinguish the two types of ER, known as rough ER and smooth ER.
- 48. Endoplasmic Reticulum (ER) RoughEndoplasmic Reticulum (RER) Smooth Endoplasmic Reticulum (SER)
- 49. Endoplasmic Reticulum (ER) RoughEndoplasmic Reticulum (RER) Smooth Endoplasmic Reticulum (SER)
- 50. Endoplasmic Reticulum (ER) RoughEndoplasmic Reticulum (RER) ▪ Rough ER is named for its rough appearance, which is due to the ribosomes attached to its outer (cytoplasmic) surface. ▪ Rough ER lies immediately adjacent to the cell nucleus, and its membrane is continuous with the outer membrane of the nuclear envelope. ▪ The ribosomes on rough ER specialize in the synthesis of proteins that possess a signal sequence that directs them specifically to the ER for processing.
- 51. Endoplasmic Reticulum (ER) SmoothEndoplasmic Reticulum (SER) ▪ The smooth ER is involved in the synthesis of lipids, including cholesterol and phospholipids, which are used in the production of new cellular membrane. ▪ In certain cell types, smooth ER plays an important role in the synthesis of steroid hormones from cholesterol. ▪ In cells of the liver, it contributes to the detoxification of drugs and harmful chemicals. ▪ The sarcoplasmic reticulum is a specialized type of smooth ER that regulates the calcium ion concentration in the cytoplasm of striated muscle cells.
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