Prokaryotic Cells – Class 11 | Chapter – 8 | Short Notes Series PDF

Prokaryotic Cells: The term ‘prokaryote’ is derived from the two Greek words pro (means earlier or before) and Karyon (means kernel). It is simply translated before the nucleus.

  • The prokaryotic cells are the most primitive cell which was discovered nearly 3.4 billion years ago.
  • These prokaryotic cells are found in ancient environments.
  • Some of the cells use chemical energy while some of them use solar energy from the sun.
  • It can be specified by their internal structure.
  • The prokaryotic cells have no nuclear membrane around them.
  • The prokaryotic cells are smaller in size and simple structure.
  • The organisms consist of prokaryotic cells termed prokaryotes.

Characteristics of Prokaryotic Cells

Prokaryotic cells have different characteristic features. The characteristics of the prokaryotic cells are mentioned below.

  • They lack a nuclear membrane.

  • Mitochondria, Golgi bodies, chloroplast, and lysosomes are absent.

  • The genetic material is present on a single chromosome.

  • The histone proteins, the important constituents of eukaryotic chromosomes, are lacking in them.

  • The cell wall is made up of carbohydrates and amino acids.

  • The plasma membrane acts as the mitochondrial membrane carrying respiratory enzymes.

  • They divide asexually by binary fission. The sexual mode of reproduction involves conjugation.

Prokaryotic Cells

Important Components of Prokaryotic Cells

The following are the important components of prokaryotic cells:

  1. Plasma Membrane – It’s an outer layer that covers the cell and separates the cell from the outer environment. It consists of phospholipid molecules.
  2. Cytoplasm – It is present inside the cell having a jelly-like structure. The cellular components are found in the cytoplasm. It mainly contains salts and enzymes.
  3. Ribosomes – It is one of the important components of prokaryotic cells where protein synthesis occurs.
  4. DNA – DNA is the genetic material of the cell circular and directs the protein created by the cells and its functions.

Prokaryotic cells are devoid of nuclear membranes, mitochondria, or Golgi bodies, there are various other components that are a part of the structure which include:

  • Nucleoid – The nucleoid is a genetic material present within the cell’s cytoplasm that is generally spherical, rod-like, or spiral-shaped.
  • Cell Wall – The wall of the cell is the exterior layer of a cell and provides shape and structure to the cell. 
  • Capsule – A capsule helps in the protection of the bacterial cells, retaining moisture and attaching themselves to the different surfaces of nutrients.
  • Flagella – Flagella refers to the long tail-like structures that help the prokaryotic cells to move from one place to another.
  • Pili – They are fine hair-like structures that are in the form of outgrowths that help the cells to attach themselves to other prokaryotic cells. 

Reproduction in Prokaryotes

A prokaryote reproduces in two ways:

  • Asexually by binary fission

  • Sexually by conjugation

Binary Fission

  1. The DNA of an organism replicates and the new copies attach to the cell membrane.

  2. The cell wall starts increasing in size and starts moving inwards.

  3. A cell wall is then formed between each DNA, dividing the cell into two daughter cells.


In this process, genes from one bacteria are transferred to the genome of other bacteria. It takes place in three ways-conjugation, transformation, transduction.

  • Conjugation is the process in which genes are transferred between two bacteria through a protein tube structure called a pilus.

  • Transformation is the mode of sexual reproduction in which the DNA from the surroundings is taken by the bacterial cell and incorporated in its DNA.

  • Transduction is the process in which the genetic material is transferred into the bacterial cell with the help of viruses. Bacteriophages are the virus that initiates the process.

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By Team Learning Mantras