Lecture on Eukaryotic and Prokaryotic Cells

Introduction

• All living things are made of cells.
• Humans and all multicellular organisms are made of eukaryotic cells.
• Eukaryotic cells are distinct from prokaryotic cells.

Key Differences Between Eukaryotic and Prokaryotic Cells

• Size: Eukaryotic cells are generally larger.
• Organism Type: Eukaryotic cells are found in multicellular organisms, but there are single-celled eukaryotes like certain protists.
• Compartmentalization: Key feature of eukaryotic cells.
  • Eukaryotic cells have compartments or "rooms" with specific functions.
  • Prokaryotic cells are like a one-room house; everything happens in one space.

Eukaryotic Cells Characteristics

• Organelles:
  • Function like organs in a body, each with specific roles.
  • Separated by membranes.
• Nucleus:
  • The defining organelle of eukaryotic cells.
  • Contains genetic material (chromosomes).
  • Name "eukaryotic" derived from "eu" (well) and "karyote" (kernel).
• Division:
  • Eukaryotic cells divide by mitosis.
  • More complex division process compared to binary fission in prokaryotes.

Important Organelles in Eukaryotic Cells

Nucleus

• Control center of the cell.
• Location of DNA.
• Site of transcription to mRNA.

Mitochondria

• Acts as the cell's power plant.
• Site of cellular respiration.
• Converts glucose into ATP for energy.

Endoplasmic Reticulum (ER)

• Surrounds the nucleus.
• Complex folded membranes.
• Site of protein synthesis (translation of mRNA).
• Factory of the cell.

Golgi Apparatus

• The cell's mail room.
• Receives proteins from ER.
• Sorts and sends proteins to their destinations inside or outside the cell.

Lysosome

• Recycling center.
• Breaks down non-functional cellular components.

Peroxisome

• Similar structure to lysosomes.
• Site for reducing reactive oxygen species to non-toxic forms.

Summary

• Eukaryotic cells are defined by compartmentalization into membrane-bound organelles.
• Each organelle has a specific function crucial for cell operations.
• Understanding organelles and their functions helps in understanding cell biology.