The main difference between the prokaryotic cell and the eukaryotic cell is that the prokaryotic cell is a primitive type of cell without membrane-bounded organelles, while the eukaryotic cell is an advanced cell with membrane-bounded organelles …

Prokaryotic cell vs. eukaryotic cell

All living organisms in the world are made up of cells. Robert Hook was the first to discover the cell in 1665. When researchers examined different cells under the electron microscope, they found that not all cells are internally similar. So according to the internal structure, cells are divided into two main types, that is, prokaryotic cell and eukaryotic cell.

A prokaryotic cell is the primitive type of cell that developed about 3.8 billion years ago. On the other hand, the eukaryotic cell is an advanced cell that developed about 2.7 billion years ago from a prokaryotic cell. Prokaryotic organisms are always unicellular, that is, they are made up of a single cell, while eukaryotic organisms can be unicellular or multicellular, that is, made up of many cells.

A prokaryotic cell is a small cell of 1-10um in size. On the other hand, the eukaryotic cell is comparatively large with a size of 10-100um. A prokaryotic cell is a simple cell without membrane-bounded organelles such as the Golgi apparatus, mitochondria, etc. On the other hand, a eukaryotic cell has all membrane-bounded organelles such as chloroplast, Golgi apparatus, lysosomes, peroxisomes, and mitochondria, etc.

A prokaryotic cell has no nucleus and the genetic material is simply embedded in the cytoplasm in the center of the cell, whereas a eukaryotic cell has a suitable nucleus with genetic material embedded in it. The DNA material is circular in the prokaryotic cell, but it is linear in the eukaryotic cell.

Prokaryotic cells reproduce asexually. On the other hand, eukaryotes can reproduce by sexual and asexual means. Examples of prokaryotic cells are bacteria and archaea, etc., while examples of eukaryotic cells are plants and animals, etc.

Comparative chart

Life originated about 3.8 billion years ago and about 750 million years after the formation of this earth. The first cell to originate was prokaryotic. So it is a simple, primitive cell without well developed organelles. The word prokaryote is derived from a Greek word where ‘Pro’ means ‘before’ and ‘karyon’ means ‘core’. This type of cell was given this name because it does not have a true nucleus. Instead, they have an irregularly shaped nucleoid region that contains the cell’s DNA and has no nuclear envelope. Prokaryotes have the only asexual mode of reproduction.

Structure

• Cell wall that provides support, rigidity and shape to the cell. It is composed of peptidoglycan or mucopeptide (polysaccharide).
• The cell membrane surrounds the cytoplasm and controls the movement of material through the cell.
• Nucleoid represents the position of the chromatin material in the cell.
• Ribosomes play an important role in protein synthesis and are small in size, that is, 70S.
• Flagellum helps in cell movement.
• Pilus is a hair-like structure that is present on the cell surface and helps in the transfer of genetic material between different cells.
• Mesosomes are the consequence of the cell membrane that plays its role in cellular respiration.
• The glycocalyx acts as a receptor and also protects the cell wall.
• The granules or inclusions play an important role in the storage of materials like proteins, carbohydrates and fats, etc.
• Endospore helps in difficult conditions.
• Fimbriae are the small hair-like structure that aids in attachment during mating.

Examples of prokaryotic cells are bacteria and archaea, etc. They play an important role in many industries such as fermentation, etc.

What is a eukaryotic cell ?

The eukaryotic cell developed from a prokaryotic cell about 2.7 billion years ago. It is an advanced type of cell with well developed organelles surrounded by membranes. The word ‘Eukaryote’ was derived from a Greek word where ‘Eu’ means ‘true’ and ‘karyon’ means nucleus because it has a true nucleus surrounded by membrane and genetic material embedded in it. Eukaryotes exhibit a sexual and asexual mode of reproduction.

Structure

• Cell Wall provides support, shape and rigidity to the cell. Its composition varies from one organism to another and can be made up of cellulose, chitin, pectin or peptidoglycan, etc.
• Cell membrane that surrounds the cytoplasm and controls cell movement.
• The Nucleus stores genetic material. Chromosomes are embedded in it. Two layers control the movement of the material through it.
• The cytoplasm is the part where all the other organelles are found.
• Mitochondria are the energy source of the cell. It plays a role in the formation of ATP.
• Chloroplast is present in plants and algae. It plays an important role in the transformation of light energy into chemical energy through the process of photosynthesis.
• The Golgi apparatus has many disc-shaped sacs known as cisterns that play a role in packing and transporting material.
• Endoplasmic reticulum has channels like structure and transports material through the cell – like lipids, proteins and carbohydrates etc. They are divided into two types, that is, rough endoplasmic reticulum and smooth endoplasmic reticulum. The rough endoplasmic reticulum also plays its role in protein synthesis due to the presence of ribosomes in it.
• Ribosomes are large, that is, the 80S, and play a role in protein synthesis.
• The cytoskeleton is made up of microtubules and microfilaments. Provides support to the cell.
• Lysosomes and peroxisomes are vesicles that are also present in the cytoplasm of eukaryotes.
• The appendages are cilia and flagella that aid in locomotion. Cilia are smaller than flagella.
• Glycocalyx is an outermost layer of polysaccharides that helps to receive signals and protects the cell.

Examples of a eukaryotic cell are plants, animals, and fungi, etc. The eukaryotic organism can be unicellular or multicellular.

Key differences

1. A primitive type of cell without membrane-bounded organelles is known as a prokaryotic cell, while an advanced cell with membrane-bounded organelles in the cytoplasm is known as a eukaryotic cell.
2. A prokaryotic cell is a primitive cell that developed about 3.8 billion years ago. On the other hand, the eukaryotic cell is an advanced cell that developed about 2.7 billion years ago from a prokaryotic cell.
3. The word prokaryote is derived from a Greek word where ‘Pro’ means’ before ‘and’ karyon ‘means’ core’ conversely, the word ‘Eukaryote’ is derived from a Greek word where ‘Eu’ means’ true ‘and’ karyon ‘means nucleus.
4. Prokaryotes do not have a true nucleus, that is, the genetic material is embedded in the cytoplasm in the center of the cell. On the other hand, eukaryotes have a true nucleus bounded by a membrane, and genetic material is embedded in it.
5. Prokaryotic organisms are always single-celled. On the other hand, eukaryotic organisms can be unicellular or multicellular.
6. A prokaryotic cell is a small cell of 1-10um while; a eukaryotic cell is comparatively large in size, ie, about 10-100 µm.
7. All membrane-bounded organelles are absent in prokaryotes; on the other hand, membrane-bounded organelles such as mitochondria, Golgi apparatus, endoplasmic reticulum, microtubules, lysosomes, and peroxisomes are present in eukaryotes.
8. Chloroplast is absent in prokaryotes and chlorophyll is dispersed in the cytoplasm, whereas eukaryotic plant cells have the proper chloroplast with embedded chlorophyll in it.
9. Flagella are submicroscopic in prokaryotes and are composed of a single fiber. On the other hand, flagella are microscopic in eukaryotes. It is a structure delimited by