General Structure of Bacteria

The prokaryotic cells have more or less the below mentioned structures and appendages common to all groups;

Capsule

Many strains of bacteria contain a tertiary, polysaccharide-based (complex carbohydrates) capsule as a form of protection. The most crucial function of capsules is to prevent the bacteria from drying up and from being phagocytosed (engulfed) by larger organisms or digestive juices. The bacterial species like E.coli and Streptococcus pneumonia, the capsule is a significant virulence component that gives them their ability to infect.

Cell Envelope

Inside the cell wall and in some strains of bacteria an outer capsule make up the 2 to 3 sections that make up the cell envelope.

Cell wall

Every bacterium is surrounded by a thick cell wall made of the polysaccharide macromolecular peptidoglycan. The cytoplasmic membrane is encircled by the cell wall, which also gives the cell shape and shields it from the external environment. Additionally, it acts as the base for protruding extensions like the flagella and pili that emerge from the cytoplasmic barrier and extend outside the cell wall.

Cytoplasm

The processes for cell development, metabolism, and replication take place in the cytoplasm, or protoplasm, of microbial species. Water, enzymes, nutrients, waste products, and gases make up its gel-like matrix, which also houses ribosomes, chromosomes, and plasmids, among other cell components. The organelle are enclosed within the cell envelope.

Plasmids

These are some unique very small, extrachromosomal DNA that is found in some species of bacteria. It has been demonstrated that plasmids play a key role in the transfer of traits with specific characteristics, such as resistance to antibiotics, heavy metal resistance, and virulence factors required for the disease of plants or animal hosts.

Plasmids are incredibly helpful tools in the sciences of molecular genetics, particularly in the field of genetic modification, due to their ability to incorporate individual genes within them and being non-essential genetic material.

Plasma Membrane

The plasma/cytoplasmic membrane, a barrier of lipids and proteins, covers the inside of the bacterium and controls the movement of substances into and out of the cell. All live cells have this characteristic structure, which gives them the ability to actively engage with their surroundings. They are dynamic and ever-changing adjust to various environmental factors and also keep the cellular components packed.

Flagella

For microorganisms that possess them, flagella (plural, flagellum) are hair-like structures that enable them to move with the help of beating like a turbine manner. A bacteria can have them across its surface or at one or both of its ends that assist the bacterium in moving toward nutrients, away from harmful substances, or in the instance of the symbiotic cyanobacteria, toward the light, etc.

Nucleoid

The chromosomal DNA is found in a cytoplasmic area known as the nucleoid which is not membrane-bound. Sometimes it may consist of more than one smaller circular DNA.

Pili

Numerous bacterial species feature pili (plural: pilus), which resemble tiny hairs that protrude from the surface of the cell. These protrusions let the bacteria connect to various tissues and surfaces like; teeth, bowels, and rocks. For conjugation, two bacteria exchange plasmid DNA pieces through specialized pili.

Ribosomes

These are made of RNA that helps in the conversion of genetic information into functional proteins; the biomolecules that carry out all of the tasks required by cells. Eukaryotic ribosomes and bacterial ribosomes are similar in function, however, bacterial ribosomes are smaller and have a marginally different molecular makeup.

Kingdom Monera is a group of prokaryotic organisms that are unicellular and lack a nucleus. They are the oldest organisms on Earth and all living things developed from them. Kingdom Monera includes two main groups – Archaebacteria and Eubacteria. They live in extreme conditions of the environment such as high temperatures, high salt concentrations, hot springs, deep oceans, and salt marshes.

Monera are either autotrophs or heterotrophs. They are also found in moist environments such as snow, and deep oceans, and as parasites in other organisms. In this article, you can find the Kingdom Monera notes.