Although eukaryotes evolved from prokaryotes, eukaryotes differ largely from their ancestors.
Eukaryotes are much larger than prokaryotes; eukaryote size about 5-100μm, while prokaryote
average 1-10μm. Also, eukaryotes have membrane-enclosed organelles, while most prokaryotes
do not. Prokaryotes reproduce using binary fission, a simpler version of eukaryotes’ mitosis/
meiosis. Eukaryotes also enclose their linear DNA strands with a nucleus; prokaryotes, however,
have no nucleus, causing their single circular DNA strand to free float in the nucleoid. While
prokaryotes and eukaryotes differ greatly, there are still some similarities. Both have the
macromolecules needed for life—carbohydrates, lipids, proteins, and nucleic acids. Prokaryotes
have cells walls, which some eukaryotes also have (plants and fungi). Both cells have ribosomes
and produce proteins similarly– through transcription and translation. Also, both cells have the
same bases for DNA/RNA (A, T, G, C, and U). Two advantages that eukaryotes have over
prokaryotes are that having membrane-enclosed organelles separate individual reactions and
allow for the localization of needed macromolecules and pH changes, permitting cells to work
more efficiently, as opposed to reactions or changes in environment impacting the entire cell.
Also, because eukaryotes have organelles, they are able to accomplish more complex reactions
and functions such as synthesizing lipid (smooth ER). Prokaryotes, however, generally have no
organelles so their functions and reactions are relatively simple. Two advantages that prokaryotes
have over eukaryotes are that their small size decreases the volume-to-surface area ratio, making
the rate of material exchange sufficient. However, because eukaryotes are much larger, the
exchange of materials across the membrane may not be fast enough to support the large volume.
Also, prokaryotes’ binary fission is much faster than how eukaryotes replicate (mitosis and
meiosis), and binary fission can also include conjugation, which increases genetic variation. This
means that prokaryotes will reproduce and evolve much faster than eukaryotes.
