Cells

Principles Module 13

Objectives

  • Discuss the reasons for limits to cell size
  • Compare eukaryotic and prokaryotic cells
  • Describe the cell theory

Key points

  • cell theory
    • cells are basic unit of life, contain reactions for life
    • cells come from other cells
  • cell size limits
    • volume increases at a faster rate than surface area, limiting exchange rate
    • diffusion within the cell becomes too limiting
  • discovery of cells required technology of microscopy, optics
    • resolution is ability to distinguish two separate points
    • resolution depends on the wavelength of radiation source (light, electron)
  • all cells have:
    • plasma membrane, DNA, cytoplasm
  • prokaryotes
  • eukaryotes

In-class activities

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