Lecture Notes: Exploring Cells and Organelles

Introduction

• Follow Amoeba Sisters on Twitter (@AmoebaSisters) and Facebook.
• Reflection on exciting science classroom days:
  • Earthworm dissection
  • Owl pellet dissection
  • Osmosis eggs
  • Genetics experiments with fruit flies
  • Discovery of an amoeba under a microscope, sparking interest in science.

Modern Cell Theory

• Cells are the smallest living units in organisms.
• All living things are made of one or more cells.
• All cells come from pre-existing cells.

Types of Cells

• Prokaryotes vs. Eukaryotes
  • Prokaryotes: Bacteria and Archaea
  • Eukaryotes: Plants, animals, fungi, protists
• Common features:
  • Genetic material
  • Cytoplasm
  • Ribosomes
  • Cell membrane
• Differences:
  • Prokaryotes: No nucleus, no membrane-bound organelles.
  • Eukaryotes: Have nucleus and membrane-bound organelles.

Cell Structures and Organelles

Cell Membrane

• Also called the plasma membrane.
• Selectively permeable: regulates entry and exit of materials.
• Maintains homeostasis.

Cytoplasm

• Jelly-like substance in cells.
• Found in both prokaryotes and eukaryotes.

Cytoskeleton

• Collection of fibers providing support and enabling movement.

Ribosomes

• Not membrane-bound.
• Found in both prokaryotes and eukaryotes.
• Responsible for protein synthesis.

Eukaryotic Organelles

Nucleus

• Contains genetic material (DNA).
• Controls cell activities.
• Contains nucleolus for ribosome production.

Endoplasmic Reticulum (ER)

• Processes and transports molecules.
• Rough ER: Has ribosomes, involved in protein production and transport.
• Smooth ER: Involved in detoxification and lipid synthesis.

Golgi Apparatus

• Packaging center for cell.
• Modifies, sorts, and ships molecules.

Mitochondria

• Powerhouse of the cell, produces ATP energy through cellular respiration.

Plant vs. Animal Cells

• Plant Cells:
  • Chloroplasts: Conduct photosynthesis, contain green pigment.
  • Central Vacuole: Large storage space.
  • Cell Wall: Provides protection and structure.
• Animal Cells:
  • Several smaller vacuoles.

Conclusion

• Differences between plant and animal cells.
• Encouragement to explore more organelles through additional research.
• Reminder to "stay curious."