How to Classify Prokaryotic & Eukaryotic Cells

By Contributing Writer

Prokaryotic and eukaryotic cells are two types of cells that exist in certain organisms. The functions and structures depend on the organism itself, and widely vary from movement to human organ function. The word "Prokaryote" means "before or without nucleus," and "Eukaryote" means "true nucleus." Prokaryotic and eukaryotic cells share many similarities, such as containing structures like the plasma membrane, DNA, ribosomes and the cytoplasm. However, there are also many distinct differences between them.

Note what types of organisms possess either a eukaryotic or prokaryotic cell. Bacteria are the only organisms that have a prokaryotic cell. Other organisms such as algae, animals and plants have eukaryotic cells. Most of the cells in the human body are also eukaryotic.

Look at the physical differences between eukaryotic and prokaryotic cells, such as their shape and size. On the surface, eukaryotic and prokaryotic cells look very different, and can often times be classified based solely on their outer appearance. Eukaryotic cells are usually larger in size and somewhat circular in shape, as opposed to prokaryotic cells, which are much smaller in size.

Take note of any outer structures. Eukaryotic cells have smooth outer surfaces. Prokaryotic cells, such as bacteria, have cilia (structures protruding from the outer surface of the cell that resemble small hairs) and flagella (longer, thicker structures protruding from the bottom of the cell), both of which aid in cell movement.

Check the organelles and inner structures of the cell. Normally, a eukaryotic cell, depending on what organism it is in, is packed with many organelles such as the rough and smooth endoplasmic reticulum, mitochondria, golgi apparatus, vacuoles, lysosomes and the nucleus. However, a prokaryotic cell is a much simpler organism, containing only a few inner structures like the nucleoid region, the plasma membrane, ribosomes and the cytoplasm. Note that prokaryotic cells do not have a nucleus. Instead they have a nucleoid region that is long in shape, rather than round like a eukaryotic nucleus.