Cell structure and function

Cell is the structural and functional basic unit of life. One who wishes to understand a living organism, should start with its building blocks, aka, cell.

This presentation gives you a general overview in concise manner.

1. Cell By: Ms Usra Hasan Images Courtesy: Principles of Anatomy & Physiology, 13 th Edition by Gerard J. Tortora & Bryan Derrickson

2. Content Learning Outcomes Introduction Components of Cell Cell Membrane Nucleus and its Chromosomes Cytoplasm and its Organelles Key Concepts References Images Courtesy: Principles of Anatomy & Physiology, 13 th Edition by Gerard J. Tortora & Bryan Derrickson

3. Learning Outcomes Student will be able to describe the structure and function of the cell membrane Student will understand the significance of the various cytoplasmic organelles in proper functioning of cells Student will be able to describe the functions of various cytoplasmic organelles. Images Courtesy: Principles of Anatomy & Physiology, 13 th Edition by Gerard J. Tortora & Bryan Derrickson

4. Introduction coined by Robert Hooke (1665) – while microscopic observing dead cork tissue based on the resemblance of small sub-divisions in cork to rooms, called cells About 10 years later, Antonie van Leeuwenhoek observed living and moving cells under a microscope Later, a theory was proposed- cells represented the basic unit of life Images Courtesy: Principles of Anatomy & Physiology, 13 th Edition by Gerard J. Tortora & Bryan Derrickson

5. nasal sinus cells onion cells 10 μ m 50 μ m Images Courtesy: Principles of Anatomy & Physiology, 13 th Edition by Gerard J. Tortora & Bryan Derrickson

6. smallest independently functioning unit of a living organism basic structural and functional unit of life most cells in human beings: 10 – 20 μm Normal Range: 2 – 120 μm What is Cell? Images Courtesy: Principles of Anatomy & Physiology, 13 th Edition by Gerard J. Tortora & Bryan Derrickson

7. Cell History Timeline Year Name of Scientist Work 1665 Robert Hooke discovered cells in cork 1670s Anton Von Leeuwenhoek discovered living cells 1833 Robert Brown described nucleus 1838-1839 Matthias Schleiden & Theodor Schwann proposed cell theory Images Courtesy: Principles of Anatomy & Physiology, 13 th Edition by Gerard J. Tortora & Bryan Derrickson

8. Components of Cell three (3) principal components: Cell Membrane Nucleus Cytoplasm Images Courtesy: Principles of Anatomy & Physiology, 13 th Edition by Gerard J. Tortora & Bryan Derrickson

9. Cell Membrane outer limiting membrane ultra thin, elastic, living membrane thickness: 7 – 10 nm dynamic and selective transport barrier Singer and Nicholson (1972) proposed a fluid mosaic model for the plasma membrane Images Courtesy: Principles of Anatomy & Physiology, 13 th Edition by Gerard J. Tortora & Bryan Derrickson

10. Fluid Mosaic Model phospho -lipid bi-layer head (hydrophilic) ends – outside tail (hydrophobic) ends – inside fixed proteins on membrane Intrinsic Extrinsic Trans-membrane Images Courtesy: Principles of Anatomy & Physiology, 13 th Edition by Gerard J. Tortora & Bryan Derrickson

11. Functions : protective digestive selective permeability links adjacent cells framework Images Courtesy: Principles of Anatomy & Physiology, 13 th Edition by Gerard J. Tortora & Bryan Derrickson

12. Nucleus spherical structure surrounded by nuclear envelope made up of chromosomes (genes present) made up of deoxy-ribo nucleic acid (DNA) and proteins contains nucleolus (densest nuclear material) Images Courtesy: Principles of Anatomy & Physiology, 13 th Edition by Gerard J. Tortora & Bryan Derrickson

13. Functions : synthesize RNA contains hereditary material cellular reproduction and multiplication Images Courtesy: Principles of Anatomy & Physiology, 13 th Edition by Gerard J. Tortora & Bryan Derrickson

14. Cytoplasm consists of cell elements between cell membrane and nucleus contains water dissolved solutes and cell organelles site of many chemical reactions Images Courtesy: Principles of Anatomy & Physiology, 13 th Edition by Gerard J. Tortora & Bryan Derrickson

15. Golgi Apparatus collection of membranous tubules and vesicles found around nucleus Functions : wrapping and packaging produce secretion granules Images Courtesy: Principles of Anatomy & Physiology, 13 th Edition by Gerard J. Tortora & Bryan Derrickson

16. Endoplasmic Reticulum complex series of tubules made up of unit membrane delivers substances Types: Agranular or Smooth ER site of steroid synthesis or detoxification important role in cardiac and smooth muscle – as sarcoplasmic reticulum Granular or Rough ER contains ribosomes site of protein or hormone synthesis Images Courtesy: Principles of Anatomy & Physiology, 13 th Edition by Gerard J. Tortora & Bryan Derrickson

17. filamentous or globular dual membrane structure inner membrane from cisternae (shelves) contains numerous enzymes Functions : contains DNA synthesize protein powerhouse of cell Mitochondria Images Courtesy: Principles of Anatomy & Physiology, 13 th Edition by Gerard J. Tortora & Bryan Derrickson

18. Lysosomes large irregular unit membrane lysozymes present Functions : digestive system eat damaged components & exogenous substances suicidal bags Images Courtesy: Principles of Anatomy & Physiology, 13 th Edition by Gerard J. Tortora & Bryan Derrickson

19. Centrioles two short cylinders visible during cell division near nucleus right angle to each other Functions : movement of chromosomes during cell division centrioles Images Courtesy: Principles of Anatomy & Physiology, 13 th Edition by Gerard J. Tortora & Bryan Derrickson

20. Micro-Tubules Micro-Filaments MICRO-TUBULES long – hollow allows movement of chromosomes, mitochondria and secretion granules MICRO-FILAMENTS solid fibers contain contractile protein – actin Functions : movement of: chromosomes, cell, secretion granules, proteins (within cell membrane) Images Courtesy: Principles of Anatomy & Physiology, 13 th Edition by Gerard J. Tortora & Bryan Derrickson

21. Secretion Granules membrane enclosed complexes Functions: store hormones and enzymes packages proteins Images Courtesy: Principles of Anatomy & Physiology, 13 th Edition by Gerard J. Tortora & Bryan Derrickson

22. Key Concepts All living organisms are made up of cell. It is the basic unit of life. All living organisms arise from pre-existing cells, followed by cell division. It comprises of – cell membrane, nucleus and cytoplasm. Cell Membrane – BARRIER Nucleus – BRAIN Cytoplasm – compartment between former two, CONTAIN VARIOUS ORGANELLES

23. Golgi Apparatus – packaging/transport proteins Endoplasmic Reticulum – synthesis of lipids and proteins Mitochondria – powerhouse/makes energy Lysosomes – suicide bags/break-down of molecules Centrioles – move chrs . during cell division Microtubules & Microfilaments - movement Secretory Granules – stores materials

24. REFERENCEs Principles of Anatomy & Physiology, 13 th Edition by Gerard J. Tortora & Bryan Derrickson https://openstax.org/books/concepts-biology/pages/3-4-the-cell-membrane https://openstax.org/books/anatomy-and-physiology/pages/3-2-the-cytoplasm-and-cellular-organelles Images Courtesy: Principles of Anatomy & Physiology, 13 th Edition by Gerard J. Tortora & Bryan Derrickson

25. END Images Courtesy: Principles of Anatomy & Physiology, 13 th Edition by Gerard J. Tortora & Bryan Derrickson