LCCC Biology 1010 Lecture on the Cell

Introduction to Cells

• Cells: Basic unit of living organisms.
• Comparison: Cells vs non-living entities like rocks or water.
• Discovery: First cells observed in 1665, named by Robert Hook as "cellulae".

Cell Theory

• Three components of Cell Theory:
  1. All organisms are composed of cells.
  2. Cells are the smallest living things.
  3. Cells arise from pre-existing cells.
• Significance: All cells today are descendants of the first living cells.

Scale and Observation of Cells

• Virus size: ~100 nanometers.
• Smallest bacterial cells: ~1 micrometer.
• Microscopy: Essential for observing cells.
  • Light microscopy for general structures.
  • Electron microscopy (scanning and transmission) for detailed structures.

Types of Cells

• Prokaryotic Cells:
  • Simple structure, no compartments, DNA not in nucleus.
  • Example: Bacteria.
• Eukaryotic Cells:
  • Complex structure with organelles like nucleus, mitochondria.
  • Examples: Animal, plant, fungal cells.

Eukaryotic Cell Structure

• Extracellular Matrix: Supports and signals between cells.
• Cell Wall: (plants, fungi, some protists) Offers support and protection.
• Cell Membrane: Phospholipid bilayer present in all cell types.
• Cytoplasm & Cytoskeleton:
  • Cytoplasm: Includes cytosol and organelles.
  • Cytoskeleton: Structure and transport within the cell.
    • Microfilaments: Movement.
    • Microtubules: Support.
    • Intermediate filaments: Stability and shape.

Organelles and Endomembrane System

• Nucleus:
  • Double membrane structure.
  • Contains DNA; site of mRNA synthesis.
• Endoplasmic Reticulum (ER):
  • Rough ER: Protein synthesis with ribosomes.
  • Smooth ER: Lipid synthesis.
• Golgi Apparatus: Modifies and packages proteins.
• Mitochondria: Powerhouse, generates ATP.
• Chloroplasts: Found in plants, site of photosynthesis.
• Central Vacuole (Plants): Water storage, rigidity.

Comparison of Cell Types

• Animal Cells:
  • Nucleus, mitochondria, no cell wall, no chloroplasts.
• Plant Cells:
  • Nucleus, mitochondria, cell wall, chloroplasts, central vacuole.
• Fungal Cells:
  • Similar to plant cells but lack chloroplasts.

Additional Resources

• Encouragement to review and watch videos for a deeper understanding of cellular components and functions.
• Videos highlighted the dynamic nature of cells and the interactions of cellular components.

Conclusion

• Recap of major cell structures and functions.
• Encouragement to further explore through engaging media such as videos.