Chapter 3, Problem 4RQ

Summary Introduction

To review:

The structural outline of peptidoglycan sacculus and its expansion during growth. Also mention two distinguishing experimental data that provide support to the present views of sacculus.

Introduction:

Murein or peptidoglycan is one of the polymers that contains amino acids and sugars. This is associated with the formation of a network like a layer outside the bacterial plasma membrane. Peptidoglycan helps in binary fission during bacterial reproduction. It is one of the significant components of the cell envelope.

The cell wall of bacteria is familiar to a sacculus, which contains a single interconnected molecule. This molecule envelops the cell. The sacculus is isolated from Escherichia coli (E.coli). This structure is porous for the organic and ion molecules. Peptidoglycan sacculus composes a cage-like closed flexible structure that covers up the cytoplasmic membrane.

The glycans are the parallel polymers of the disaccharides from the interconnected peptide chains. The layers are composed of an alternating association of N-acetylmuramic acid and N-acetylglucosamine held together by peptide chains. The cross-linked interconnected parallel bridges of glycan strands are formed by the expansion of peptides. The mesh cage-like structure of the sacculus helps in holding the cells together.

The septation and expansion of cell walls are observed through an electron microscope (EM). Fluorescence microscopy can also be used to reveal particular classes of proteins that are vital during the process of growth as well as separation. Each class of protein reflects a particular color in the fluorescence microscopy, which helps in a better understanding of the involved proteins during these processes.