This document summarizes the structural organization of prokaryotic cells. It describes the main components of prokaryotic cells, including the plasma membrane, cell wall, capsule, nucleoid, ribosomes, plasmids, and flagella. It provides details on the composition and functions of these various structures, such as that the cell wall provides shape and protection and varies in chemical makeup between archaea and bacteria. The document also distinguishes between gram-positive and gram-negative bacterial cell walls.

2. International Medical University
Presentation of Biology
Presented by:
Chauhdary Muhammad Touqeer & Seemab Zahid
Submitted to:
Dr. Ainagul Jalilova
Group # 25

3. TITLE:
THE STRUCTURAL ORGANIZATION OF
PROKARYOTES.
THE PROPERTIES OF PROKARYOTIC CELL

4. PROKARYOTIC CELL:
 PROKARYOTIC CELL IS THE PRIMITIVE TYPE OF CELL THAT
LACKS MEMBRANE BOUNDED ORGANELLES INCLUDING
NUCLUES , MITOCHONDRIA ETC.
 THE PROKARYOTE WORD IS DRIVED FROM TWO GREEK
WORDS “PRO” AND “KARYOV”
 ITS IS DIVIDED INTO TWO DOMAINS i.e. “ARCHAE” &
“BACTERIA”

5. PROKARYOTIC CELL:

6. MAIN COMPONENTS:
 Plasma membrane
 Cell wall
 Capsule
 Nucleoid
 Ribosomes
 Plasmid
 Flagella

7. The Plasma Membrane
 The plasma membrane is a thin lipid bilayer (6 to 8 nanometers)
that completely surrounds the cell and separates the inside
from the outside.
 Its selectively-permeable nature keeps ions, proteins, and other
molecules within the cell, preventing them from diffusing into
the extracellular environment, while other molecules may move
through the membrane.
 The general structure of a cell membrane is a phospholipid
bilayer composed of two layers of lipid molecules.

8. The Plasma Membrane

9. CELL WALL:
 The cell wall is a protective layer that
surrounds some cells and gives them
shape and rigidity.
 The chemical composition of the cell
walls varies between Achaea and
bacteria. It also varies between bacterial
species.
 Cell walls contain peptidoglycan
composed of polysaccharide chains that
are cross-linked

10. Types of prokaryotic cell on the
basis of cell wall:
 Gram positive :
Gram-positive organisms
typically lack the outer
membrane found in gram-
negative organisms and
contain a large amount of
peptidoglycan in the cell wall,
roughly 90%.
 Gram negative :
Gram-negative bacteria
have a relatively thin cell
wall composed of a few
layers of peptidoglycan.

11. Capsule
 Capsule is an extra layering on a prokaryotic cell
 It provides protection to the cell
 It provides the virulence factors
 It provides protection against immune system of other
organisms
 It helps in attachment.
There is another factor that helps in attachment which is
called Pilli.

12. Nucleoid:
 In prokaryotic cell there is no membrane
bounded nucleus.
 The chromatin material floats in the center of the
cell called nucleoid.
 It is an irregularly shaped region.

13. Plasmid:
 A circle of double stranded DNA that is
separate from the chromosomes.
 It is found in the Bacteria & Protozoa.
 It is used in Genetic engineering.

14. Ribosomes:
 Ribosomes Are the organelles which makes
proteins
 On the basis of information provided by DNA .
 The difference of ribosomes of prokaryotes with
the eukaryotes is of size (30s smaller part & 50s
of greater part whereas “S” is Sediments.

16. Flagella:
 Flagella is a whip-like structure present
outside of the prokaryotic cell.
 It help in the movement of the cell.