Cell
- “Building block of life”
- “Fundamental unit of life”
- “Structural or functional basis of life”
Cell Study
- Cytology
- Cyto: Cell
- Logy: Study
Cell Discovery
- First discovered by Robert Hook in 1665
- Book: Micrographia
- Observed in Cork
- Cork is obtained from bark of tree
- Dead cell
- Cork Cell: Honeycomb Shape
- Cell word comes from Latin word “Cellula”, which means “Small Room”
Other Discovery
- Antonie Van Leeuwenhoek
- 1674: Free living cells in water
- Father of Modern Cytology
- Robert Brown
- 1831: Nucleus
- Purkinje
- 1839: Named protoplasm
Cell Theory
- “All the plants and animal are composed of cell”
- Basic unit of life
- Given by: Schleiden and Schwan, in 1838
- Rudolf Virchow later published his famous cell Theory “Omnis Cellula e Cellula” in 1855
- New cell are formed from the pre-existing cells.
Notes
- Largest cell: Ostrich’s egg
- Smallest cell: Mycoplasma(bacteria) or PPLO
- Smallest cell in Women: RBC
- Largest/Longest cell in Male: Neuron
- Can be 1m long
- Largest cell in human(female): Ovum
- Smallest cell in human(male): Smerm > RBC
Parts of cell
Cell Membrane/Plasma membrane
- Protects the cell: Bodyguard
- Thin, elastic, flexible
- Outer most covering
- Made up of: Protein(50%) and Lipid(Fat)(50%) or Lipoprotein or Phospholipid
- Selectively/Semi permeable(only allows some materials)
- Living
- Provides definite shape and holds
- Flexiblity enable the cell to engulf
- Engulf: Food and other material from external engvironment
Cell Wall
- Only present in plants/bacteria/fungus/algae cell
- Non-living
- Freely permeable
- Determines shape
- Provides strength and tugidity to cells
- Made up of:
- Plant cell: Cellulose
- It is Polymer of glucose
- Bacteria:Peptin/Peptidoglycan(murein)
- Fungus: Chitin
- Algae: Cellulose/Pectin
- Plant cell: Cellulose
| Feature | Cell Membrane | Cell Wall |
|---|---|---|
| Presence | All Cell | Plant, Fungi, bacteria, algae |
| Flexibility | Flexible | Rigid |
| Permeability | Selectively permeable | Permeable to small molecules |
Nucleus
- Nucleus is known as “Brain of the Cell”, it controls the activities of different cell organelles.
- Discovered by: Robert Brown
- Celluylar Componenct
- Contrally Located
- Large in size
- Largest cell structure
- Componenct of Nucleus
- Nuclear Envelope
- Composed of Membrane
- Cover Nucleus
- Separates nucleus from cytoplasm
- Permits material between nucleoplasm and cytoplasm
- Nucleoplasm
- Liquid ground substance of nuclear envelope
- Type:
- Nucleolus
- One/more in numbers
- Form protein forming centrs: Ribosome
- Chromatin material
- Entangles mass of Thread like structures
- During cell division they get organised in chromosome
- Nucleolus
- Nuclear Envelope
Chromosomes
- Thread like structure
- Visible during cell division
- Component:
- DNA
- Proteins(Histone)
| Feature | Animal Cell | Plant Cell |
|---|---|---|
| Cytoplasm | ✓ | ✓ |
| Nucelus | ✓ | ✓ |
| Cell Membrane | ✓ | ✓ |
| Mitochon | ✓ | ✓ |
| Cellwall | X | ✓ |
| Chloroplast | X | ✓ |
| Vacuole | X | ✓ |
| Centrosome and Centrioles | ✓ | X |
| Lysosomes | ✓ | X |
| Glycogen | Primary energy storage | Primary energy storage |
| Shape | Round or irregular | Rectangular or cube-shaped Export to Sheets |