Presentation on
BACTERIAL CELL WALL, FUNGAL CELL WALL & PLANT CELL WALL
in Molecular Biology & Genomics
Presented by-Subash ChowdhuryRoll : 86422nd BatchDepartment of Pharmacy, USTC
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
Different shapes of Bacteria
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
Peptido-glycan Polymer (amino acids + sugars)
Sugars; NAG & NAM N-acetylglucosamine
(G) N-acetymuramic acid
(M)
Structure and Chemical composition of Bacterial cell wall
Structure of peptidoglycan
Structure of peptidoglycan
According to the position of peptidoglycan layer in the cell wall bacteria are classified into two types.
Gram positive bacteriaGram negative bacteria
Types of bacterial cell wall
In gram positive bacteria The thick peptidoglycan layer in the cell wall that encases their cell membrane
In Gram negative bacteria the thin peptidoglycan layer of their cell wall is sandwiched between an inner cell membrane and a bacterial outer membrane.
Comparison between the Gram(+) & Gram(-) Cell
wall
Gram staining
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
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
The cell wall is made up of:1) chitin (polymers of acetylated amino sugar N-
acetyl-glucosamine)2) glucan3) 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
Basic component of fungal cell wall
Secondary wall
Primary wall
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
Glucans
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
Cell wall is a rigid & rough. Situated outside the cell membrane. The cell wall was discovered by Robert Hooke in
1665.
Plant Cell Wall
Major Regions of the Cell Wall
Components of the cell wall
Components of the cell wall
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
Thank you
Top Related