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Features of Prokaryotic Cell with Diagram

Unicellular are single-celled organisms because their cells only contain one nucleus. They are referred to as prokaryotes. Multiple components within the prokaryotic cell ensure its viability. Lets learn more about features of prokaryotic cell with diagram.

Prokaryotic Cell Definition

“Prokaryotic cells are those that don’t have a true nucleus and organelles that are attached to the cell membrane”.

Prokaryotic cells are single-celled microorganisms that are thought to have been the first to form on Earth. Bacteria and Archaea are both types of prokaryotes. Photosynthesis is done by cyanobacteria, which are prokaryotic organisms. Since a prokaryotic cell only has one membrane, all of the reactions happen in the cytoplasm. They can be free-living or parasites.

Prokaryotic Cell Structure

Simple structures make up prokaryotic cells. They don’t have a true nucleus, and the genetic material isn’t surrounded by a membrane. Instead, it can be seen coiled in the cytoplasm of the cell. Here is a list of the parts of a prokaryotic cell.

Capsule: This is an exterior protective coating discovered on some prokaryotic cells that aids in moisture retention and adhesion to nutrients and surfaces.

Cell Wall: This is the outermost layer of prokaryotic cells, which gives them their size and shape. It also safeguards the cell against injury.

Membrane: The cell membrane surrounds the cytoplasm and helps control the flow of substances into and out of the cell.

Cytoplasm: Cytoplasm is a gel-like substance that is mostly made of water and contains enzymes, organic molecules, and salts.

Pilli: These are structures that look like hair and are found on the surface of the cell. They help the cell stick to a surface. A pilus is a single structure, and its shorter parts are called fimbriae. These parts can also be called “appendages.”

Flagella: These are long projecting structures that resemble whips and contribute to the cell’s ability to move around.

Plasmids: The DNA in a prokaryotic cell is contained in plasmids. These DNA configurations are either circular or double-stranded.

Ribosomes: The prokaryotic ribosome molecules are associated with the plasma membrane. These are 70S ribosomes which are composed of 30S smaller and 50s larger subunits. The molecules are made from messenger RNA.

Nucleoids: It is the area of the cytoplasm that contains the prokaryotic DNA molecule/ genetic material.

Prokaryotic Cell Diagram

Labelled diagram of prokaryotic cell

Figure 1: Labelled diagram of prokaryotic cell

Prokaryotic Cell Components

Glycocalyx: In some prokaryotic cells glycocalyx is a part of the cell envelope or capsule and is composed of macromolecules.

Mesosomes: These are extensions of the cell or plasma membrane in the form of lamella or tubules. Their functions are: Assisting in cellular respiration and secretion, Cell wall formation, Increasing the surface area of enzymatic content and plasma membrane and Genetic material replication and distribution in daughter cells.

Inclusion bodies: They are free bodies observed in the cytoplasm of a prokaryotic cell and act as storage units for reserve materials.

Chromatophores: These membrane extensions are specifically found in cyanobacteria and have photosynthetic pigments inside.

Types of Prokaryotic Cells

Bacterial Cells: There are unicellular creatures in the soil and in our bodies. Their forms and compositions vary. Peptidoglycan is the structural component of the cell wall. Pili, flagella, and a capsule are just a few of the unusual bacterial features. They also have plasmids, which are extrachromosomal DNA. Endospores are hard, dormant structures that can help them survive in harsh environments. When the right conditions are met again, the endospores germinate and spread.

Archaeal Cells: They can be found in sites as diverse as hot springs, dirt, wetlands, and even the human body. They’re equipped with flagella and a cell wall. There is no peptidoglycan in an archaeal cell wall. Archaeal membranes contain lipids with a different stereochemistry than eukaryotic ones. Archaea, like bacteria, only contain a single chromosome, which is also circular. They also possess plasmids.

Features of Prokaryotic Cells

The DNA is contained in a nucleoid, which lacks a protective barrier. The ribosome, which is necessary for protein synthesis, is present in abundance in these cells. Mesosomes are membrane-bounded organelles found in some prokaryotes that aid in respiration. Flagella and pili are examples of structures used by some prokaryotes. Both flagella and pili aid in the transfer of genetic material between cells and in the movement of the organism as a whole.

The lack of Golgi complexes and mitochondria-like organelles with well-defined membrane boundaries. Proteins called histones are required for eukaryotic cells to produce chromosomes, although they aren’t present. There is no evidence of mitosis or a nucleolus. The cytoplasmic membrane, which is formed below the cell wall, functions as the mitochondrial membrane and transports respiratory enzymes.

Reproduction in Prokaryotes

Binary fission: The process begins with DNA replication, during which the molecule is copied and then two copies of itself adhere to the cell membrane. Once the cell has grown to twice its initial size, the membrane pinches inwards between the two molecules. Following the separation of the two DNA molecules, a cell wall forms between them, resulting in the creation of two identical daughter cells.

Recombination: Transferring the genetic material from one cell to another. There are three stages to the procedure.

  • Conjugation: The process of gene transfer takes place between two cells through a protein tube-like structure called a pilus.
  • Transformation: It is a type of sexual reproduction where the cell takes genetic material from the surroundings and incorporates it into its genetic material.
  • Transduction: In this process, the genetic material is transferred to another cell with the help of viruses.

FAQ

FAQs on Features of Prokaryotic Cell with Diagram

The genetic material of prokaryotic cells is held in a nucleoid, as opposed to a membrane-bound nucleus. Moreover, prokaryotic cells are typically absent of membrane-bound organelles.

Prokaryotic cell reproduction is asexual. The majority of prokaryotic cells undergo binary fission, in which they divide into two daughter cells.

About 3.5 billion years ago, the first prokaryotic cells appeared. Evolutionary theorists argue that eukaryotic cells descended from prokaryotic cells since they appeared later.

Blue-green algae

Bacteria

Mycoplasma

All prokaryotic cells have a nucleoid, genetic material in the form of DNA and RNA, protein-producing ribosomes, and a cytoskeleton in the cytoplasm.