Cell the structrural and functional unit of life
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Cell is the basic structural and functional unit of life. All organisms start as a single cell that cannot be seen with the naked eye. The invention of microscopes allowed scientists to discover that cells are the smallest unit of structure and function, as stated in the Cell Theory. Cells come in various shapes and sizes depending on their function, and contain organelles that allow different metabolic processes to occur. All activities of living organisms result from cellular activities like growth, movement, feeding, and reproduction.
Cell the structrural and functional unit of life
- 1. Cell- The Structural and functional unit of life Magic of life Jegatheeswari karthik
- 2. Basic concepts • Definition • Cell Theory • Size and shape of cells • Cell types- Unicellular and Multicellular Prokaryotic and Eukaryotic • Structure of Cell
- 3. Cell • Structural and functional unit of life • Smallest part of the body having individual existence and can perform essential functions of life. • Each Cell has its own life.
- 4. Cell • All Cells are basically alike in chemical composition and metabolic processes. • All organisms including ourselves started our life journey as a single cell. • Cannot be seen by our naked eyes.
- 5. Cell- Definition •A cell is the smallest unit of life which has definite structure and perform specific functions.
- 6. Invention of microscope • Simple microscope • Antony Van Leeuwenhoek - Dutch Scientist- (1632-1723) • Magnifying power - 200 times • Uses simple biconvex lens
- 8. Compound microscope • Robert Hooke (1635-1703), English Scientist • Two lenses are used • 1. Magnifies the image. 2000 times (ocular lenses) • 2. Gather light which is bent by glass lenses to magnify the images.
- 11. Electron microscope • 2,00,000 times magnification • Uses beam of electrons which are bent by magnets.
- 13. Cell Theory • Matthias Schleiden, German Botanist - 1838 • Theodor Schwann, German Zoologist - 1839 • Rudolf Virchow, German Pathologist - 1858
- 14. Cell Theory - Major points • Cell is the smallest unit of Structure of all living things. • The cell is the unit of function of all living things. • All cells arise from pre-existing cells.
- 15. Types of organisms • Unicellular Organisms • Amoeba Paramecium Bacteria Chlamydomonas
- 16. Types of organisms • Multicellular Organisms • Volvox Rose plant Humans
- 17. Size of cells Smallest Cell( 6.2–8.2 µm)
- 18. Size of cells • Largest Cell ( ? )
- 20. Why cells are small? • Different regions of a cell can communicate with each other to function effectively. • Cells have large surface area to volume ratio for greater diffusion of substances in and out of the cell.
- 21. Shape of Cells • Circular and bi-concave - RBC • Amoeboid - WBC • Long - Nerve Cell • Bean shaped - Guard Cells
- 22. Shape of cells • Each cell type has its own role to play in helping our bodies to work properly, and their shapes help them carry out these roles effectively. The following cell types all have unusual shapes that are important for their function. • RBC are circular and biconcave for easy passage through blood capillaries.
- 25. Structure of a cell There are three basic components of cell. They are • Cell membrane • Cytoplasm • Nucleus
- 26. Structure of cell • Outer membrane In animals only cell membrane or plasma membrane is present. In plants, in addition to that cell wall is also present. Cell wall is present in few prokaryotic bacteria and Fungi.
- 27. Functions • Transport of substances • Support • Maintain shape • Separates contents of cell from environment.
- 29. Cell Wall • Made up of Cellulose • Gives shape and rigidity to the cell. • Freely permeable • Non-living membrane
- 31. Functions • Different functions will takes place by different organelles. • All metabolic activities occur here. • First step of respiration will takes place here.
- 35. Mitochondria • It has its own ribosomes • It synthesis respiratory enzymes.
- 39. Golgi apparaus • In plants it is called by Dictyosomes. FUNCTIONS • Helps in Synthesis and secretion of enzymes, hormones • Formation of acrosome of Sperm.
- 40. Ribosomes
- 41. Lysosomes
- 42. Prokaryotic cell
- 43. Eukaryotic cell
- 44. Lysosomes • The main Function is Intracellular Digestion • It Digest Cartilages during formation of bones.
- 50. Protoplasm ● It is the living matter ● It is the total substance of a living cell (Cytoplasm and Nucleus) ● It is a translucent fluid which may be colourless, graying or brownish based on the cell. ● Protoplasm of every cell contains the common chemical composition of Carbon, Hydrogen, Oxygen, Nitrogen, Sulphur and Iron. ● These elements are in the form of specific compounds such as water, proteins, carbohydrates, fats and mineral salts.
- 51. Protoplast ● Protoplasts are cells of plants, bacteria, and fungi with removed cell walls. ● Protoplast is a naked cell in which the cell wall is removed through enzymatic degradation while the protoplasm is the collective term that is used to refer to both cytoplasm and the nucleus. This is the key difference between protoplast and protoplasm.
- 52. Cell inclusions Cytoplasmic inclusions are diverse intracellular non-living substances that are not bound by membranes. Inclusions are stored nutrients, secretory products, and pigment granules.
- 53. Difference between cell organelles and cell inclusions The main difference between cell organelles and cell inclusions is that the cell organelles are membrane-bound compartments that perform a particular function in the cell whereas the cell inclusions are non-living materials in the cytoplasm. Vacuoles are granules are examples of cell inclusions.
- 54. Vacuoles ● Clear spaces in the Cytoplasm ● Filled with water and various substances in solution ● In plants the vacuoles are very large and are called cell sap ● In animals the vacuoles are small and are fewer in number
- 55. Granules Glycogen granules in the liver and muscle cells, lipid droplets in fat cells, pigment granules in certain cells of skin and hair, and crystals of various types.. These structures were first observed by O. F. Müller in 1786.
- 56. Difference between plant and animal cell Feature Plant Cell Animal Cell Cell Wall Is made of cellulose. Absent Centromere Absent Present Vacuoles Large and prominent If any are small and temporary Plastids Present Absent Size Large with distinct outlines Smaller with less distinct boundaries Cytoplasm Not so dense Denser with more granules Arrangement of Only a thin lining, mostly pushed to the Fills the entire space
- 57. Every activity of a living organisms is the outcome of cellular activity 1. All organisms grow due to the growth in size and increase in number of cells. 2. Repair due to cell division. 3. Movement of the body is due to the contractility of the cells or the cellular parts. ● Eg. moving a hand, walking ● Flight of birds ● Touch me not plant ● Bending of plant parts ● Opening and closing of stomata
- 58. Every activity of a living organisms is the outcome of cellular activity 4. Feeding and nutrition 5. Circulation of Blood 6. Respiratory gases transport 7. The body protection 8. Sensation 9. Thermoregulation 10. Reproduction 11. Absorption of Water 12. Photosynthesis 13. Flowers attract insects 14. Inheritance of characters.