The difference between viruses and bacteria The difference between bacteria and viruses can be explained in three aspects: 1. Morphology Bacteria are much larger than viruses, usually measured in microns, while viruses are measured in nanometers. The external form of bacteria is mostly spherical, rod-shaped, spiral, and also named as cocci, bacilli and spiral bacteria. Viruses are polyhedral in structure, in order to achieve the best stable structure, as well as the best specific surface area, viruses more than a dodecahedron. 2, structure Although bacteria do not have a nucleus only similar to the nucleus structure, but bacteria still have a certain cell structure, namely, cell wall, cell membrane, cytoplasm. Further, the Gram staining mechanism developed based on the differences in the structure and composition of bacterial cell walls classifies bacteria into Gram-negative and Gram-positive bacteria. Viruses do not have the cellular structure described above; it consists of a nucleocapsid wrapped in genetic material. 3, survival and reproduction Bacteria can be divided into autotrophic and heterotrophic according to their survival, that is, part of the bacteria can be photosynthetic (such as some cyanobacteria) or inorganic substances into organic substances of chemical energy (such as some sulfur bacteria) to achieve the purpose of survival; the other part of the bacteria and people can not synthesize their own organic substances for their own growth and reproduction, must take nutrients from the outside to The other part of bacteria, like human beings, cannot synthesize organic material for their own growth and reproduction, and must take nutrients from outside to feed themselves. Viruses are not as capable as bacteria, they can only survive by parasitizing their hosts, but this does not mean that viruses cannot be completely separated from their hosts, they can be temporarily separated from their hosts and stay as dormant bodies in a very “hostile” environment. Bacteria reproduce mainly by bifurcation, which is often referred to as one to two or two to four. Viruses, on the other hand, must invade the host and use the host’s synthetic machinery to synthesize the proteins and other substances they need to build their own “bodies”. Bacteria are microorganisms, while viruses are DNA (deoxyribonucleic acid), which, like proteins, is synthesized from amino acids. Viruses and bacteria differ in the way they are structured and infected. A virus is a non-cellular form of microorganism that is small, so small that it cannot be seen even with a high magnification light microscope and can only be observed with an electron microscope. It has no organelles and consists of a genomic nucleic acid and a protein shell. The genome contains only one type of nucleic acid, either ribonucleic acid (RNA) or deoxyribonucleic acid (DNA). Bacteria are very different from viruses in the way they survive infection Bacteria are single-celled organisms. Under the right conditions in the body, such as on various mucous membranes, they may reproduce themselves to cause disease. By changing the reproduction conditions of bacteria, it is possible to kill them and cure the disease. Viruses, on the other hand, are non-cellular microorganisms that lack a complete enzyme system and cannot carry out metabolic activities independently, and therefore cannot reproduce themselves like bacteria. When a virus is infected, it first enters the human bloodstream and forms a viraemia. Subsequently, it can only parasitize strictly in human target cells, using the cellular biosynthetic machinery to replicate itself and release offspring viruses. In other words, the virus can only survive and replicate once it has entered the human cells, at which point the disease can be cured if the virus can be identified and can distinguish which is the infected cell and which is the healthy cell, killing both the virus and the infected cell. Unfortunately, so far, the existing synthetic drugs and treatments do not have this recognition and differentiation function, and it is not possible to kill all cells in the body. The only ones with this specific recognition function are the body’s own immune cells and immunoglobulins. If the infected person’s immunity is low at this time, specific antibodies are not sufficient to clear the virus, and it is self-evident that viral diseases are difficult to treat. Moreover, after the hepatitis B virus enters the liver cells, it can also change the nature of the liver cell membrane. The body’s immune system is disrupted, mistaking its own liver cells as the “enemy” to destroy them, causing liver cell damage. Even if you kill the virus with antiviral drugs, your own immune function will continue to attack the liver cells. Therefore, hepatitis B is difficult to cure and requires immunomodulatory therapy in addition to antiviral therapy. Bacteria are a large group of single-celled microorganisms that can live independently, and their metabolism involves taking nutrients from their surroundings to obtain energy and raw materials to synthesize their own components. Bacteria have a large surface area, an active and diverse metabolism, and rapid growth and reproduction. Some products are harmful to humans, such as toxins and enzymes produced by bacteria and their pathogenicity; some products are beneficial to humans, such as vitamins produced by bacteria; some products are useful for identifying and diagnosing bacteria, such as pigments and sugar breakdown products.