1. Presentation on
BACTERIAL CELL WALL, FUNGAL CELL
WALL & PLANT CELL WALL
in Molecular Biology &
Genomics
Presented by-
Subash Chowdhury
Roll : 864
22nd Batch
Department of Pharmacy, USTC

2.  Bacteria (singular: bacterium)
constitute a large domain of
prokaryotic microorganisms.
 The study of bacteria is known as
bacteriology, a branch of
microbiology.
 Bacteria was first discovered by
Antony van Leeuwenhoek in 1970s.
Bacteria
Fig:- structure of bacteria

3. Different shapes of Bacteria

4.  Bacterial cell wall is a rigid structure which gives the
shape of the cell.
 Unique to bacteria.
 Protecting cell from osmotic lysis.
Bacterial cell wall
Cell Wall
Cytoplasm
Cell membrane

5.  Peptido-glycan Polymer
(amino acids + sugars)
 Sugars; NAG & NAM
 N-acetylglucosamine (G)
 N-acetymuramic acid (M)
Structure and Chemical composition of
Bacterial cell wall

6. Structure of peptidoglycan

7. Structure of peptidoglycan

8.  According to the position of peptidoglycan layer in the cell
wall bacteria are classified into two types.
Gram positive bacteria
Gram negative bacteria
Types of bacterial cell wall

9.  In gram positive bacteria The thick peptidoglycan layer in
the cell wall that encases their cell membrane

10. In Gram negative bacteria the thin peptidoglycan layer of
their cell wall is sandwiched between an inner cell
membrane and a bacterial outer membrane.

11. Comparison between the
Gram(+) & Gram(-) Cell wall

12. Gram staining

13.  Protect cells against osmotic shock (most important) and
physical damage.
 Regulation of substance transport into and out of cells.
 Contain genome.
 Contain supplemental genetic information such as
resistance to antibiotics, production of toxins and tolerance
to toxic environment.
 Take part in protein synthesis.
 Movement of cells.
 Mineral storage of cells.
Function of bacterial cell wall

14.  Fungi are eukaryotes
 Nearly all multicellular (yeasts
are unicellular)
 Spore-bearing protists that lack
chlorophyll.
 Two types:-
1. Yeasts
2. Molds (filamentous
and multicellular)
Fungi

15. The cell wall is made up of:
1) chitin (polymers of acetylated amino sugar N-
acetyl-glucosamine)
2) glucan
3) Proteins
Glucan and chitin are components of the primary
wall.
Proteins are components of the secondary wall.
Other components include chitosan, melanins and
lipids.
Enzymes include cellulase which acts on cellulose of
plants.
Fungal cell wall

16. Basic component of fungal
cell wall
Secondary wall
Primary wall

17.  Chained polymer β(1-4) N-acetyl-glucosamine.
 Microfibril
Microfibrils can be of various shapes:
 in yeast: short and thick
 in hyphal wall: long and interwoven
 Septa
Chitin

18. Glucans

19.  Protects against osmotic lysis
 Acts as a molecular sieve
 Contains pigments for protection
 Binding site for enzymes
 The outermost surface of the cell wall
1) provides a medium between the cell and the environment
2) a site where antigen and agglutinin gets attached to the
substrate, host and other cells.
Function of fungal cell wall

20.  Cell wall is a rigid & rough.
 Situated outside the cell membrane.
 The cell wall was discovered by Robert Hooke in 1665.
Plant Cell Wall

21. Major Regions of the Cell Wall

22. Components of the cell wall

23. Components of the cell wall

24.  determining cell shape
 support and mechanical strength
 prevents the cell membrane from bursting
 controls cell growth and cell volume
 physical barrier
 carbohydrate storage
Functions of the Cell Wall