›

Prokaryote vs Eukaryote Cells

Notes

Prokaryote vs Eukaryote Cells

Sections

PROKARYOTE VS EUKARYOTE

Prokaryotes

  • No nucleus
  • Domains Bacteria and Archaea
  • Smaller (diameter between 1 and 10 µm)

Eukaryotes

  • Cells have nucleus
  • Domain Eukaryotes (Eukarya)
  • Larger (diameter between 10 and 100 µm)

SHARED FEATURES

PROKARYOTES ONLY

  • Circular chromosome found in nucleoid region of cell
  • Cell wall (made of different molecules than eukaryotic cell walls)

EUKARYOTES ONLY

  • Linear chromosomes in membrane bound nucleus
  • Membrane bound organelles

Full-Length Text

  • Here we will explore the general similarities and differences between eukaryotic cells and prokaryotic cells.
  • First, draw a table to explore some key concepts.
  • Denote that there are two main classifications for cellular life:
    • Prokaryotes, single-celled organisms without a nucleus and,
    • Eukaryotes, organisms whose cells have a nucleus.
  • Denote that prokaryotes, whose estimated biomass is more than ten times greater than the biomass of eukaryotes, are found only in two domains:
    • Bacteria and Archaea.
  • Denote that eukaryotes are found only in the third domain: Eukaryotes (sometimes referred to as Eukarya).

Now, let's look into the key similarities and differences between prokaryotic cells and eukaryotic cells. Consider that these truisms are prone to exceptions because of the wide variety of prokaryotes.

  • Draw a cylindrical prokaryotic cell.
  • Nearby, draw a eukaryotic cell, which has an ovoid, non-cylindrical shape.

Start a list to designate the cellular features that are shared, prokaryote-only, and eukaryote-only.

  • Label the plasma membrane surrounding both cell types: prokaryote and eukaryote.
  • Label the cytosol in both cells.
    • All cells have a cytosol, the semi-fluid substance within the plasma membrane.
  • Note that all cells use DNA to store genetic information, though there are some differences in the shape and location of chromosomes.
  • Draw the prokaryotic DNA.
    • Note that it is usually a single circular chromosome located in a region of the cell called the nucleoid.
  • Within the eukaryote, draw the nucleus surrounded by the nuclear envelope.
  • Within the nucleus, draw the chromosomes.
  • Write that eukaryotic chromosomes are linear and located in the membrane-bound nucleus.
  • Draw ribosomes in both cells.
  • Write that both types of cells use ribosomes for protein synthesis, though there are some differences in size and composition.
  • Draw the cell wall surrounding the prokaryotic cell.
    • Most prokaryotic cells are surrounded by a cell wall.
    • Some eukaryotes have cell walls too, but they are made up of different molecules than prokaryotic cell walls.
  • Within the eukaryotic cell, draw mitochondria, endoplasmic reticulum, endosomes, and Golgi stacks.
  • Write that eukaryotes possess internal, membrane-bound structures called organelles.
  • Finally, note that prokaryotic cells are generally smaller with a diameter between 1 and 10 µm while eukaryotic cells are generally bigger with a diameter between 10 and 100 µm.

This ends our diagram on the differences between prokaryotic and eukaryotic cells.

UNIT CITATIONS:

  1. Campbell, N. A. & Reece, J. B. Biology, 7th ed. (Pearson Benjamin Cummings, 2005).
  1. Purves, W. K., Sadava, D. E., Orians, G. H. & Heller, H. C. Life: The Science of Biology. (Macmillan, 2000).
  1. Roy, S. H. Comprehensive MCQs in Biology. (Golden Bells, 2005).
  1. Pommerville, J. C. Fundamentals of Microbiology: Body Systems Edition. (Jones & Bartlett Publishers, 2014).
  1. Alberts, B., Bray, D., Hopkin, K., Johnson, A., Lewis, J., Raff, M., Roberts, K. & Walter, P. Essential Cell Biology, 3rd ed. (Garland Science, 2010).
  1. Campbell, M. K. & Farrell, S. O. Biochemistry, 8th ed. (Cengage Learning, 2014).