Chapter 6

Chapter 6: A Tour of the Cell

• Overview of Cell Biology: Cells are the basic unit of structure and function, categorized into prokaryotic and eukaryotic types.

• Microscopy: Cells are often too small to see without magnification. Light Microscopy (LM) can magnify up to 1,000 times, focusing on image clarity and contrast. Electron Microscopes (EM) include SEMs for surface imaging and TEMs for internal structures.

• Eukaryotic Cells: Feature membrane-bound organelles, including plasma membrane, cytosol, chromosomes, and ribosomes. The nucleus contains DNA and is surrounded by a nuclear envelope.

• Ribosomes: Composed of rRNA and protein; sites of protein synthesis.

• Endomembrane System: Includes nuclear envelope, ER, Golgi apparatus, lysosomes, and vacuoles; involved in protein traffic and metabolism.

  • ER: Smooth ER synthesizes lipids; Rough ER is involved in protein production.

  • Golgi Apparatus: Modifies and packages proteins.

  • Lysosomes: Contain enzymes for digestion and recycling.

  • Vacuoles: Store substances; central vacuoles maintain turgor in plants.

• Mitochondria & Chloroplasts: Mitochondria are for ATP production, while chloroplasts conduct photosynthesis, both supporting the endosymbiotic theory.

• Cytoskeleton: A network supporting cell structure and motility, comprised of microtubules, microfilaments, and intermediate filaments.

• Extracellular Components: Include cell walls in plants and ECM in animals, aiding in structure and communication through cell junctions.

• Conclusion: Cell components work in synchrony for life processes.