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, 13th 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, 13th 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, 13th 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, 13th Edition by Gerard J. Tortora & Bryan Derrickson

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

8. Components of Cell
• three (3) principal
components:
1. Cell Membrane
2. Nucleus
3. Cytoplasm
Images Courtesy: Principles of Anatomy & Physiology, 13th 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, 13th 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
i. Intrinsic
ii. Extrinsic
iii. Trans-membrane
Images Courtesy: Principles of Anatomy & Physiology, 13th Edition by Gerard J. Tortora & Bryan Derrickson

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

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

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