Cell the structrural and functional unit of life

ICSE

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

7. 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.

8. Electron microscope 2,00,000 times magnification Uses beam of electrons which are bent by magnets.

9. Cell Theory Matthias Schleiden, German Botanist - 1838 Theodor Schwann, German Zoologist - 1839 Rudolf Virchow, German Pathologist - 1858

10. 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.

11. Types of organisms Unicellular Organisms Amoeba Paramecium Bacteria Chlamydomonas

12. Types of organisms Multicellular Organisms Volvox Rose plant Humans

13. Size of cells Smallest Cell( 6.2–8.2 µm)

14. Size of cells Largest Cell ( ? )

15. 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.

16. Shape of Cells Circular and bi-concave - RBC Amoeboid - WBC Long - Nerve Cell Bean shaped - Guard Cells

17. 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.

18. Structure of a cell There are three basic components of cell. They are Cell membrane Cytoplasm Nucleus

19. 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.

20. Functions Transport of substances Support Maintain shape Separates contents of cell from environment.

21. Cell Wall Made up of Cellulose Gives shape and rigidity to the cell. Freely permeable Non-living membrane

22. Functions Different functions will takes place by different organelles. All metabolic activities occur here. First step of respiration will takes place here.

23. Mitochondria It has its own ribosomes It synthesis respiratory enzymes.

24. Golgi apparaus In plants it is called by Dictyosomes . FUNCTIONS Helps in Synthesis and secretion of enzymes, hormones Formation of acrosome of Sperm.

25. Ribosomes

26. Lysosomes

27. Prokaryotic cell

28. Eukaryotic cell

29. Lysosomes The main Function is Intracellular Digestion It Digest Cartilages during formation of bones.

30. 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.

31. 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.

32. 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.

33. 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.

34. 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

35. Granules G lycogen 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.

36. 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 Cytoplasm Only a thin lining, mostly pushed to the periphery Fills the entire space

37. Every activity of a living organisms is the outcome of cellular activity All organisms grow due to the growth in size and increase in number of cells. Repair due to cell division. 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

38. 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.