Surface Layers – Cell Membrane

Surface Layers – Cell Membrane

— Functions:

— control permeability

— transport e’s and protons for cellular metabolism

— contain enzymes to synthesis and transport cell wall substance and for metabolism

secret hydrolytic enzymes regulate cell division.

Structure

— Fluid mosaic model, phospholipid bilayer and protein (structure and enzymatic function).

— Similar to eukaryotic cell membrane but some differs. e.g. sterols such as cholesterol present in Eukaryotes not there in Prokaryotes.

— Similar to eukaryotic cell membrane but some differs. e.g. sterols such as cholesterol present in Eukaryotes not there in Prokaryotes.

Cytoplasm

Contains 80% water , Nucleic acids , proteins , carbohydrates , lipids, inorganic ions.

Host bacterial chromosomes, ribosomes, mesosomes and inclusion bodies.

Bacterial Chromosomes

A single large circular double stranded DNA with no histone proteins. The only proteins associated with the bacterial chromosomes are the ones for DNA replication, transcription etc.

Mesosomes

A large invaginations of the plasma membrane, irregular in shape.

increase in membrane surface, which may be useful as a site for enzyme activity in respiration and transport.

may participate in cell replication by serving as a place of attachment for the bacterial chromosome.

Inclusions

Not separated by a membrane, but of distinct shape.

Granules of various kinds:

— glycogen,

— polyhydroxybutyric acid droplets (PHB) i.e. fat droplets

— inorganic metaphosphate (metachromatic granules

in general, starvation of cell for almost any nutrients leads to the formation of this to serve as an intracellular phosphate reservoir.