Prokaryotic and Eukaryotic Cells
Prokaryotic Cells
- Prokaryotic cells are the simplest and earliest forms of life on Earth. They are found in bacteria and archaea.
- They are smaller than eukaryotic cells, measuring usually about 1 to 5 micrometres.
- These cells have a lack of true nucleus and the genetic material is not enclosed in a nuclear envelope.
- The genetic material in prokaryotic cells is in the form of a single, free-floating strand of DNA.
- They lack internal membrane-bound organelles such as mitochondria, Golgi apparatus and endoplasmic reticulum.
- Prokaryotic cells have ribosomes which are smaller than eukaryotic ones.
- Most have a cell wall surrounding the entire cell, as well as a cell membrane.
Eukaryotic Cells
- Eukaryotic cells are more complex and are found in any organisms higher than bacteria, including plants, animals, and fungi.
- These cells are larger than prokaryotic cells, typically ranging in size from 10 to 100 micrometres.
- Eukaryotic cells possess a central nucleus which is covered by a nuclear membrane and contains the cell's DNA.
- They have multiple, linear strands of DNA packaged in chromosomes.
- Eukaryotic cells contain membrane-bound organelles, including the nucleus, mitochondria, endoplasmic reticulum, Golgi apparatus, vacuoles, and in the case of plant cells, chloroplasts.
- They also have ribosomes; however, they are larger than those found in prokaryotic cells.
- Animal eukaryotic cells are surrounded by a cell membrane only while plant eukaryotic cells are surrounded by a cell wall as well as a cell membrane.
Similarities Between Prokaryotic and Eukaryotic Cells
- Both prokaryotic and eukaryotic cells are surrounded by cell membranes which protect the cells and control the movement of substances in and out of the cell.
- Both types of cells contain cytoplasm, a jelly-like substance where most of the cell’s metabolic reactions occur.
- Both prokaryotic and eukaryotic cells contain ribosomes, which are the sites of protein synthesis.
- Both types use DNA as their genetic material which controls all of a cell's functions and characteristics.