Prokaryotic & Eukaryotic Cells The cell is the basic unit of life. Based on the organization of their cellular structures, all living cells can be divided into two groups: which is prokaryotic and eukaryotic

Size – Nearly all prokaryotes are much smaller in size that a eukaryotic cell. Prokaryotes usually range between 1 – 10 micrometers, whereas eukaryotic cells range from 10 micrometer – 1 millimetre. Eukaryotes have a smaller surface area to volume ratio than prokaryotes, and thus have lower metabolic rates and longer generation times. In some multicellular organisms, cells specialized for metabolism will have enlarged surface areas, such as intestinal vili.

The prokaryotes are a group of organisms that lack a cell nucleus, or any other membrane-bound organelles. They differ from the eukaryotes, which have a cell nucleus. Most are unicellular, but a few prokaryotes such as myxo bacteria have multicellular stages in their life cycles. The prokaryotes are divided into two domains: the bacteria and the archaea. Reproduction Bacteria and archaea reproduce through asexual reproduction, usually by binary fission or budding.

Evolution – Eukaryotic cells are more evolutionarily advanced, having arisen from prokaryote-like predecessors. Energy-related Organelles (Eukaryotes) – Mitochondria and chloroplasts are membrane-bound organelles, so are not found in prokaryotes. Mitochondria are found in nearly all eukaryotic cells (other than a few oddball parasites) and chloroplasts are found only in eukaryotes that photosynthesize (capture sunlight energy and turn it into food). These two energy-related organelles have their own DNA and are believed to have originally been independent prokaryotes that formed a symbiotic relationship with another cell.

A eukaryote is an organism whose cells contain complex structures enclosed within membranes. The defining membrane-bound structure that sets eukaryotic cells apart from prokaryotic cells is the nucleus, or nuclear envelope, within which the genetic material is carried. All species of large complex organisms are eukaryotes, including animals, plants and fungi, although most species of eukaryotic protists are microorganisms. Cell division in eukaryotes is different from that in organisms without a nucleus (prokaryotes). There are two types of division processes. In mitosis, one cell divides to produce two genetically identical cells. Eukaryotes represent a tiny minority of all living things; even in a human body there are 10 times more microbes than human cells.

Similarities… prokaryotic Both are covered by a cell membrane Both contain RNA Both have DNA as their genetic material Both are made from the same basic chemicals Both have ribosomes (the structure of which proteins are made) Both regulate the flow of nutrients and wastes that enter and leave them Both have similar basic metabolism like photosynthesis and reproduction Both require a supply of energy eukaryotic