Viruses, bacteria, and prions are microscopic, living beings. All three can be found inside and outside hosts. Bacteria and viruses are more similar with each other than a prion with either one. None are even closely related, though. The three of them have different reproduction methods, structures, and choices of hosts. These are not the only differences by a long shot, but it is a start.
A virus is an infectious agent. It is very small in size. They cannot reproduce without the use of a host. A capsid surrounds the virus. The capsid is made of protein subunits. It has three main functions, first, to protect the nucleic acid within from digestion. Secondly, hold proteins that attach to ...view middle of the document...
Integration is in between penetration and biosynthesis. In this stage, viral DNA combines with the host cell’s DNA and can lay dormant for a long period of time.
Viruses are host specific. They have receptors that able them to attach and penetrate a host cell, but that cell has to be the right fit. Hosts could be anything from microscopic bacteria to an enormous whale. It all just matters on the type of receptors that the virus has on its capsid matching up to what a host cell has on its membrane.
Bacteria are usually single-celled, microscopic living organisms that can be found everywhere. Their structure is a little more complex than viruses. Bacteria have a cytoplasmic membrane, chromosome, flagella, and pili. The cytoplasmic membrane helps regulate what can go in and out of the cell. The chromosome holds the bacteria’s genetic makeup. Nothing holds the chromosome, though, because bacteria have no nuclei. The flagella’s main purpose is movement. Pili help the bacterial cell to attach to surfaces. It also helps with bacterial mating. Bacteria also come in different shapes. These shapes help to name the bacteria. If the bacteria are spherical then it is labels cocci. If the bacteria are rod shaped then it is called bacilli and if the bacteria are in spirals then it is labeled spirilla.
Bacteria reproduce by binary fission. In binary fission, the parent cell replicates its DNA and splits into two identical daughter cells. Three ways that make bacterial DNA diverse is transduction, transformation, and conjugation. In transduction, bacteriophages carry portions of DNA from one cell to another. During transformation, the bacteria collect free pieces of DNA from around their cells. In conjugation, two cells are shortly connected and exchange genetic material.
Bacteria are on and in everything. Not all bacteria are bad. Some can grow inside of things, like humans, without causing any harm. Others can cause infections and serious bacterial diseases. Some bacteria even attack plants, such as Erwinia.
A prion is a wrongly folded protein that causes the protein to be an infectious agent. Prions are hard to distinguish because it is hard to tell the difference between a protein and an infectious prion. Prions are just proteins that had the wrong code to be built. Normal prions have the same structure as the infectious prion, so bodies do not recognize the threat. Prions are a chain of amino acids.
Just like normal proteins, prions do not reproduce. Prions are said to chance harmless proteins into prions. Enzymes cannot break down prions. As prions change normal proteins, without ever being broken down to be used, they steadily grow in numbers.
Prions mainly affect humans and animals, but plants can transfer prions into a host if eaten. Even infected meat can bring in prions. One example is in deer. Chronic wasting disease can be caused from eating alfalfa, corn, and tomatoes that has the prion in it.
An example of a disease that each of these...