Biological World

  Beneficial Aspects of Bacteria Bacteria play a crucial role in various aspects of the economy, influencing industries such as agriculture, medicine, biotechnology, and environmental management. Here's an overview of the economic importance of bacteria: 1. Agriculture (a) Nitrogen Fixation : Certain bacteria, like Rhizobium species, can fix atmospheric nitrogen into a form that plants can absorb. This is vital for crop production and reduces the need for chemical fertilizers, saving costs and promoting sustainable agriculture. Rhizobium form symbiotic relationships with legumes, converting atmospheric nitrogen into a form usable by plants. This natural fertilization process reduces the need for synthetic fertilizers, saving farmers money and minimizing environmental impact.   (b) Biological Pest Control: Bacteria such as Bacillus thuringiensis (Bt) produce toxins harmful to insects, serving as natural pesticides. Bt-based products are widely used in agriculture t...

  The components of Viruses Capsid:  Capsid is the protein shell enclosing the viral genome. The nucleic acid together with some associated basic proteins forms the core of the virion. The relatively small genomes of the viruses cannot make many proteins. Therefore the viruses cannot afford too many proteins for building the capsid. The capsid of tobacco mosaic virus, for example, contains only a single polypeptide. In the icosahedral viruses, the capsid is made from one to several polypeptides. The polypeptides fold to form the basic structural unit of the capsid, known as a protomer. The protomers may associate with each other to form a capsomer. In icosahedral viruses five protomers form a pentameric capsomer, or six protomers are associated to form a hexameric capsomer. In a single virion, both pentameric and hexameric capsomers are present to give the characteristic shape and size to virion. The number of total capsomers is characteristic for the particular virus In helic...

                                  PROPERTIES OF VIRUS              Viruses are unique entities that straddle the line between living and non-living things. They have a set of distinct properties that define their nature and behavior: 1.  Size : Viruses are extremely small, typically ranging from 20 to 300 nanometers in diameter. They are much smaller than bacteria. 2.  Structure : Viruses consist of a core of genetic material (either DNA or RNA) surrounded by a protein coat called a capsid. Some viruses also have an outer lipid envelope derived from the host cell membrane. 3.  Nucleic Acids : Viruses contain either DNA or RNA as their genetic material, but not both. This genetic material can be single-stranded or double-stranded. 4.  Genome Size : The genome of viruses is relatively small compared to other organisms, encoding only a few proteins nec...

  Glycocalyx The glycocalyx of bacteria is a protective and often adhesive layer that surrounds the bacterial cell membrane. It is composed of a complex mixture of carbohydrates, glycoproteins, and glycolipids. The glycocalyx can serve various functions for bacteria, including protection, adhesion, and evasion of the host immune system. Here are some key points about the glycocalyx of bacteria: The glycocalyx is primarily composed of polysaccharides, which are long chains of sugar molecules. These sugar molecules can be in the form of carbohydrates, glycoproteins (sugar-protein complexes), and glycolipids (sugar-lipid complexes). Types of Glycocalyx : 1. Capsule : A bacterial capsule is a dense, well-organized layer of glycocalyx that is firmly attached to the bacterial cell wall. Capsules are often composed of repeating units of simple sugars and are associated with pathogenic bacteria. They protect the bacteria from phagocytosis by the host's immune cells. 2. Slime Layer ...