Lecture Notes: Exploring Cells with Amoeba Sisters

Introduction

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• Recollection of exciting science classroom experiences
  • Earthworm dissection, owl pellet dissection, osmosis eggs, genetic experiments with fruit flies
  • Notable experience: observing an amoeba in pond water
    • Sparked a lifelong interest in science

Modern Cell Theory

• Cells are the smallest living unit in organisms
• All living things are made of one or more cells
  • Unicellular (e.g., amoeba) vs. Multicellular (e.g., humans)
• All cells come from pre-existing cells
• Cells contain genetic information, can divide, and have specialized functions

Types of Cells

• Two major groups: Prokaryotes and Eukaryotes

Prokaryotes

• Include bacteria and archaea
• Characteristics:
  • No nucleus or membrane-bound organelles
  • Have genetic material, cytoplasm, ribosomes, and cell membranes

Eukaryotes

• Include plants, animals, fungi, and protists
• Characteristics:
  • Have nucleus and membrane-bound organelles

Exploring Eukaryotic Cells

Cell Membrane

• Also known as the plasma membrane
• Selectively permeable, maintains homeostasis

Cytoplasm

• Jelly-like material inside the cell
• Contains organelles and cytoskeleton for support and movement

Organelles

• Ribosomes:
  • Not membrane-bound, present in all cells
  • Responsible for protein synthesis
• Nucleus:
  • Contains DNA, controls cell activities
  • Includes nucleolus, where ribosomes are produced
• Endoplasmic Reticulum (ER):
  • Rough ER:
    • Has ribosomes, involved in protein production and transport
  • Smooth ER:
    • Involved in detoxification and lipid production
• Golgi Apparatus:
  • Packaging center, modifies and sorts molecules
  • Determines molecule destination, including secretion
• Mitochondria:
  • Powerhouse, produces ATP via cellular respiration
• Chloroplasts (Plant Cells):
  • Conduct photosynthesis, contain green pigment
• Vacuoles:
  • Storage functions
  • Plant cells have a central vacuole, animal cells have multiple small vacuoles
• Cell Wall (Plant Cells):
  • Provides additional protection and shape

Eukaryotic Cell Process

• DNA in nucleus provides instructions for protein synthesis
• Ribosomes synthesize proteins, can be on Rough ER
• Proteins transported via vesicles to Golgi apparatus for sorting
• Secretion occurs through vesicles from Golgi to membrane

Conclusion

• Encouragement to explore further organelles and stay curious
• Additional resources suggested for further exploration