Similarities and differences of prokaryotic and eukaryotic cells

Similarities and differences of prokaryotic and eukaryotic cells

For those that didn’t know, there are many similarities between prokaryotic and eukaryotic cells. These are two types of cells that make up living organisms, and this article will cover all the parallelism between them.

The basic unit of life is cell. Living organisms are divided into two groups on the basis of their cellular structure: prokaryotes and eukaryotes. The former evolved 2 billion years before the evolution of latter. Around 3.5 billion years ago, prokaryotic organisms dominated our planet. Then, about 1.5 billion years ago, a nucleated cell called eukaryote evolved. The Cambrian explosion, around 0.5 billion years ago, helped in the evolution of multicellular organisms.

Animals, plants, fungi, protozoans, and algae all come under eukaryotic cells, with bacteria being the only organisms that are prokaryotes. They are smaller and simpler in structure as compared to eukaryotes. Prokaryotic cellules have a large surface-to-volume ratio, that helps the nutrients easily and rapidly reach interior parts of the cell. Eukaryotic cellules have a limited surface area, thus, making it very difficult for the nutrients to readily diffuse in the interior parts of the cells. Thus, eukaryotes have complex organs that help them carry out metabolism and other important functions for the survival of the organisms. Although the cells are different in many ways, the main similarity is survival of the organism and carrying out the same process of life.

The Similarities

Similarities and differences of prokaryotic and eukaryotic cells

Similarities and differences of prokaryotic and eukaryotic cells

There are many other cell types in different forms, like neurons, epithelial, muscle cells, etc. But prokaryotes and eukaryotes are the only true cell structures and types. The following points will cover the main similarities.

  • The genetic material, i.e., presence of DNA is common between the two cells.
  • The presence of RNA is common.
  • They both have a cell membrane covering them.
  • Resemblances are seen in their basic chemical structures. Both are made up of carbohydrates, proteins, nucleic acid, minerals, fats, and vitamins.
  • Both of them have ribosomes, which make proteins.
  • They regulate the flow of nutrients and waste matter that enters and exits the cellules.
  • Basic life processes like photosynthesis and reproduction are carried out by them.
  • They need energy supply to survive.
  • They both have ‘chemical noses’ that keep them updated and aware of all the reactions that occur within them and in the surrounding environment.
  • Both these organisms have a fluid-like matrix called the cytoplasm that fills the cells.
  • Both have a cytoskeleton within the cell to support them.
  • They have a thin extension of the plasma membrane which is supported by the cytoskeleton.
  • Flagella and cilia are found in eukaryotes; likewise endoflagella, fimbriae, pili and flagella are found in prokaryotes. They are used for motility and adhering to surfaces or moving matter outside the cells.
  • Some prokaryotic and eukaryotic cellules have glycocalyces as a common material. This is a sugar-based structure that is sticky and helps the cells in anchoring to each other; thus, giving them some protection.
  • They have a lipid bilayer, known as the plasma layer, that forms the boundary between the inner and outer side of the cell.

There are many differences between them, of which age and structure are the main attributes. It is believed by scientists that eukaryotic cells evolved from prokaryotic cells. In short, both are the smallest units of life.

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Cells are the basic building block of life.

The smallest living organisms only need one of these building blocks and others only need a handful.

More complex life forms on the evolutionary tree, such as moss, saguaro cacti and black bears, are made up of millions or trillions of cells that cooperate to form an individual organism.

Most of the organisms in the world are made of prokaryotic cells, and these are usually unicellular. Prokaryotes are bacteria and archaea.

TL;DR (Too Long; Didn't Read)

Most prokaryotes are unicellular and are either archaea or bacteria. Their cells are smaller than eukaryotic cells. Eukaryotes include larger, more complex organisms such as plants and animals. Only eukaryotes have membrane-bound organelles and a nucleus. Prokaryotes divide via using binary fission, while eukaryotic cells divide via mitosis.

Eukaryotes reproduce sexually through meiosis, which allows for genetic variance.

Prokaryotic cells reproduce asexually, copying themselves. Despite this, gene transfer processes still allow for genetic variance. One of these is transduction in which viruses move DNA from one bacterium to another.

Prokaryotes vs. Eukaryotes: The Basics

All of known life on Earth is sorted into a classification system that begins with three categories called domains and spreads out with each descending rank. This is what is commonly known as the tree of life.

The three domains are:

  1. Archaea
  2. Bacteria
  3. Eukarya

The organisms in Archaea and Bacteria are prokaryotes, while the organisms in Eukarya have eukaryotic cells.

The Archaea domain has subcategories, but scientific sources differ on whether these categories are phyla or kingdoms. They are:

  • Crenarchaeota
  • Euryarchaeota
  • Korarchaeota

The Bacteria domain used to continue directly down the tree into the single Monera kingdom. However, newer classification systems eliminate Monera and divide the Bacteria domain into the two kingdoms of Eubacteria and Archaebacteria, which is sometimes written as Archaea but should not be confused with the domain of Archaea.

The Eukarya domain is divided into four kingdoms. These are:

  • Plantae
  • Fungi
  • Protista
  • Animalia

All plant, protist, fungal and animal cells are eukaryotes. Most of them are multicellular, although there are some exceptions. In contrast, prokaryotes – bacteria and archaea – are single-celled organisms, with only a few exceptions. Prokaryotes tend to have smaller cell sizes than eukaryotes.

Major Differences in Cell Structure

The reason for the difference in cell sizes between prokaryotic cells and eukaryotic cells belongs to the different structure and organization between the two types of cells.

The lack of membrane-bound organelles in prokaryotes might be the most noticeable difference. While eukaryotic cells contain organelles enclosed in membranes – two examples would be the Golgi body and the endoplasmic reticulum – prokaryotes do not.

Prokaryotes also lack a membrane-bound nucleus, which is another organelle. Without a nucleus or any other organelles, prokaryotic cells are incapable of the kinds of specialized functions that eukaryotic cells engage in.

They cannot perform the advanced functions that cells with many supportive organelles can do.

Similarities and differences of prokaryotic and eukaryotic cells

••• Sciencing

Eukaryotes store their DNA as chromosomes within the nucleus, but prokaryotes lack the nucleus.

Instead, most of their DNA is in one chromosome-like structure that sits in an area of the cytoplasm called the nucleoid. This nucleoid does not have a membrane of its own. Additional bits of DNA called plasmids are shaped like rings and exist in the cytoplasm outside the nucleoid.

Differences in Organization

Prokaryotic cells engage in reproduction through a process of cell division called binary fission.

Eukaryotic cells use a different process of cell division called mitosis, which involves a constant cycle of cell growth and development.

There are frequent checkpoints for the cell to go through, monitoring the cell’s external and internal conditions, and redirecting the cell’s resources and functions when necessary.

A fundamental part of all life on Earth is the transfer of genetic material to future generations.

Eukaryotes reproduce sexually through a process called meiosis, which randomly sorts the genes from two parents to form the DNA of the offspring.

Sexual reproduction maximizes the genetic variability of the offspring of two parents, strengthening the genetic line and minimizing the risk of a random mutation wiping out most of a population.

Prokaryotes reproduce asexually, which creates a precise copy of the original cell. Genetic variance comes in the form of less complex processes of gene transfer than eukaryotes, such as transduction. In this process, genes are transferred from one bacterial cell to another by means of viral cells.

The viruses grab the plasmids from one bacterium and transfer it to another bacterial cell. The DNA in the plasmid becomes integrated with the other DNA of the recipient cell.

Prokaryotic CellEukaryotic Cell
Membrane Bound Organelles Present No Yes, includes things like mitochondria, golgi body, endoplasmic reticulum, chloroplast, etc)
Domains Bacteria and Archaea Eukarya
Kingdoms Eubacteria and Archaebacteria Plantae, Fungi, Animalia, Protista
Nucleus Present No Yes
How DNA Is Stored Nucleoid Chromosomes
Cell Reproduction/Division Binary fission Mitosis (division of somatic cells) and Meiosis (creation of cells used for sexual reproduction)
Ribosomes Present Yes Yes
Plasma Cell Membrane Present Yes Yes

Similarities Between Prokaryotes and Eukaryotes

For all the differences between prokaryotic cells and eukaryotic cells, they have some features in common, too.

Both cells have a plasma membrane, which serves as a barrier between the inside of the cell and the outside.

The plasma membrane uses certain molecules embedded within it to allow foreign bodies to pass into the cell or to allow matter within the cell to pass out of the cell.

Proteins embedded in the membrane do something similar, as well: they act as pumps that push matter into or out of the cell, rather than allowing it to pass through.

Both prokaryotes and eukaryotes have ribosomes.

Ribosomes are small organelles used to synthesize proteins as the cell needs them. They can either float freely in the cell or sit on the surface of the rough endoplasmic reticulum in eukaryotic cells, (giving it the designation of "rough," in comparison to its smooth sibling that lacks ribosomes).

They receive messages from messenger RNA molecules, telling them what proteins the cell needs.

They translate these messages into protein molecules by assembling amino acids. Although the process of protein synthesis works differently in prokaryotes and eukaryotes, it is is closely related and involves ribosomes in both cases.

Related cell biology topics:

  • Cell Wall: Definition, Structure & Function (with Diagram)
  • Cell Membrane: Definition, Function, Structure & Facts
  • Animal vs Plant Cells: Similarities & Differences (with Chart)
  • Nucleus: Definition, Structure & Function (with Diagram)
  • Golgi Apparatus: Function, Structure (with Analogy & Diagram)
  • What Happens to the Nuclear Membrane During Cytokinesis?

What are 5 differences between prokaryotic and eukaryotic?

Prokaryotes don't have membrane-bound organelles whereas eukaryotes have. ... What is the difference between Prokaryotic and Eukaryotic Cells?.

What are 4 similarities between prokaryotic and eukaryotic cells?

Similarities between Prokaryotic vs Eukaryotic Cells The cell wall is present in both. In both, there are four types of major molecules that are common to both. The process of DNA copying is similar in both. Some major metabolic pathways are common in both.

What are 5 similarities between prokaryotic and eukaryotic cells?

Similarities between eukaryotic and prokaryotic cells.
Cell Membrane. ... .
Genetic Material. ... .
Ribosomes. ... .
Cytoplasm. ... .
Cell size. ... .
Cell arrangement. ... .
True membrane-bound nucleus..