Lecture Notes: Eukaryotic Cells

Introduction to Cell Types

• All living things are made of cells.
• Types of cells: Eukaryotic cells (found in humans and multicellular organisms) and prokaryotic cells.

Characteristics of Eukaryotic Cells

• Size: Generally larger than prokaryotic cells.
• Found in multicellular organisms, but also in single-celled organisms like certain protists.
• Compartmentalization:
  • Cells are divided into different compartments called organelles.
  • Analogy: Like rooms in a house, each organelle has a different function.

Organelles in Eukaryotic Cells

• Organelles: Membrane-bound compartments within cells, each with specific functions.

The Nucleus

• Central organelle
• Function: Contains genetic material (DNA).
• Role: Control center of the cell, where DNA is transcribed into mRNA.

Mitochondria

• Function: Site of cellular respiration, converting glucose into ATP.
• Role: Known as the power plant of the cell, providing energy.

Endoplasmic Reticulum (ER)

• Structure: Folded membranes enclosing a continuous compartment.
• Function: Site of protein synthesis.
• Analogy: Factory of the cell.

Golgi Apparatus

• Structure: Folded membranes, but not a continuous compartment.
• Function: Modifies, sorts, and ships proteins from the ER.
• Analogy: Mail room of the cell.

Lysosome

• Structure: Spherical, single plasma membrane.
• Function: Breaks down non-functional cellular components into basic components for reuse.
• Analogy: Recycling center of the cell.

Peroxisome

• Structure: Similar to lysosome.
• Function: Reduces reactive oxygen species into non-toxic forms.

Differences Between Eukaryotic and Prokaryotic Cells

• Eukaryotic Cells:
  • Have membrane-bound organelles.
  • Genetic material contained within a nucleus.
  • Divide by mitosis.
• Prokaryotic Cells:
  • Lack membrane-bound organelles.
  • Genetic material floats freely.
  • Divide by binary fission.

Conclusion

• Defining aspects of eukaryotic cells: Compartmentalization into organelles, presence of a nucleus, and complex cell division process (mitosis).