Lecture Notes

Introduction

• Topic overview: Discussion on the structure and function of cells.
• Importance of understanding cells in biology.

Cell Theory

• All living organisms are composed of cells.
• The cell is the basic unit of life.
• All cells arise from pre-existing cells.

Types of Cells

Prokaryotic Cells

• Lack a nucleus.
• Smaller and simpler than eukaryotic cells.
• Examples: Bacteria and Archaea.

Eukaryotic Cells

• Have a nucleus and membrane-bound organelles.
• Larger and more complex.
• Examples: Plant cells, animal cells, fungi, and protists.

Cell Structure

Key Organelles

• Nucleus: Contains genetic material (DNA).
• Mitochondria: Powerhouse of the cell, produces energy (ATP).
• Ribosomes: Site of protein synthesis.
• Endoplasmic Reticulum (ER):
  • Rough ER: Studded with ribosomes, synthesizes proteins.
  • Smooth ER: Synthesizes lipids and detoxifies drugs.
• Golgi Apparatus: Modifies, sorts, and packages proteins and lipids for secretion.
• Cell Membrane: Semi-permeable barrier, regulates what enters and leaves the cell.

Cell Functions

• Metabolism: All chemical processes within a cell.
• Homeostasis: Maintaining a stable internal environment.
• Reproduction: Cells divide to produce new cells.

Conclusion

• Recap of the importance of cells in biological systems.
• Encouragement to study cell biology further for a deeper understanding.