microbiology

Bacterial Plasma membrane: Why do bacteria have plasma membrane apart from having cell wall? Apart from having cell wall, Bacteria are also surrounded by several layers below it which have their own roles and plasma membrane is an important one among all. The presence of the plasma membrane is so special because it gives  protection and shape to the cytoplasm and without which the cytoplasmic constituents would have been spilled out into the environment. Despite the presence of the outer layers surrounding the plasma membrane, the interaction of the cell with its environment, uptake of nutrients and elimination of wastes from the cell is carried out in a selective manner by the plasma membrane. The selectively permeable nature makes them capable of allowing only few ions and molecules to enter the cell that are necessary in the growth and nourishment of the cell thereby preventing the entry of unwanted ones. There are also several other activities such as the photosynthesis, r...

Bacterial cell walls: Why do these tiny organisms need a cell wall?  Bacterial cells are so tiny that they are bestowed with great protection which they need to protect themselves against harmful substances and also foreign particles that may kill them. Bacterial cells are also surrounded by plasma-membrane just like the Eukaryotic cells, which is usually a double layered one. Many bacteria also have external structures like flagella, pilli, fimbriae which help them move and also to attach to the surfaces such as rocks or the host cells in case of infection. There are several layers surrounding the bacterial cell which all when put together are called as the cell Envelope. The cell has a fluid like cytoplasm with several cell organelles like the Nucleoid, ribosomes, inclusions and many others within it. The cytoplasm is given protection and a shape by the plasma membrane surrounding it and also the transport of nutrients and important substances occurs through it which allows t...

BACTERIA: INTRODUCTION : Bacteria are the prokaryotic micro-organisms, most of which do not contain any membrane bound nucleus or other membrane bound cell organelles. According to the five Kingdom classification, The  prokaryotes  were placed within the kingdom Monera and protista. But later on, started the prokaryotic controversy, according to which, there are certain bacterial phyla such as the  planctomycetes , which had their genetic material enclosed within a membrane and also other membrane bound cell organelles such as the  anammoxosome (the site for oxidation of ammonia) and this was not in accordance with the prokaryotic definition. Hence, two new domains namely Bacteria and Archaea came into existence into which these prokaryotes were placed. These bacterial cells are in different shapes and arrangements  which are explained as follows: Shapes and Arrangement of Bacteria cells :  Bacteria exist in a variety of shapes and arrangement of their...

Microbiology: The study of micro-organisms Introduction : Microbiology is a branch of Science which deals with the study of various micro-organisms that are invisible to the naked eye. Our Eye Usually has the ability to detect a speck of about 0.2 mm in diameter and anything beyond that size needs an aid such as a Microscope. Many organisms such as Bacteria, some of the Fungi have a size of Micrometers which can be seen only under a Microscope and hence, their observation and study comes under the branch of Microbiology. These microbes are believed to be very primitive and that they might have originated in the beginning of the origin of life on the Earth. Earlier, the place of these Micro-organisms was in the kingdoms Monera, Protista and Fungi of the Five kingdom classification which was later not accepted by the Microbiologists because of the contradictions on the term Prokaryotes. Bacteria, Archae and Eukarya are the three domains into which all the cellular organisms have bee...