The Discovery of Cells

Robert Hooke first discovered cells in 1665 using a primitive microscope. Today, we know the cell is the fundamental organisational unit of life. While some organisms like Amoeba are unicellular, complex life forms are multicellular.

Cell Structure

A typical cell is enclosed by a plasma membrane made of lipids and proteins. This selectively permeable membrane regulates the movement of materials. Plant cells also have a rigid cell wall composed of cellulose. Inside, the nucleus acts as the control center, containing DNA, while the cytoplasm houses various organelles.

Essential Cell Organelles

Organelles perform specialized functions:

  • Endoplasmic Reticulum (ER): Intracellular transport and manufacturing surface.
  • Golgi Apparatus: Modifies, packages, and stores products.
  • Lysosomes: The cell's waste disposal system (suicide bags).
  • Mitochondria: The powerhouse of the cell, generating ATP.
  • Plastids: Found in plants (e.g., chloroplasts for photosynthesis).