In bacteria, DNA and RNA are floating in the cytoplasm. Bacteria have a cell wall, a cell membrane, flagella, and ribosomes but do not have a nucleus. Viruses are sub-microscopic particle, about 20-300 nanometers. They have two main parts: a capsid which is composed of protein subunits and an inner core of nucleic acid, either DNA or RNA. They also have spikes made from a glycoprotein.
"Prions: On the Trail of Killer Proteins." Prions: On the Trail of Killer Proteins. University of Utah, n.d. Web. 10 Apr.
What makes viruses, prions, and bacteria unique? Well to start off I will compare and contrast them, then explain what makes each one of the different and special. Viruses are what make us sick their only purpose is to attach to a host cell and reproduce and repeat the cycle. Most scientists do not think that they are a living organism. They have an inner DNA core surrounded by a protein shell.
Only systems containing nucleic acids are capable of this phenomenon. With this reasoning, a better definition is the unit element of a continuous lineage with an individual evolutionary history. Because of viruses inability to survive when not in a host, they must have evolved from other forms of life. The origin of viruses is an easy thing to theorize about so many hypothesese have been made. One such hypothesis is that viruses were once complete living parasites.
Prions on the other hand aren’t considered to be living at all, because all they are are malformed proteins that usually cause degenerative diseases that are extremely difficult to cure, if not utterly impossible. Bacteria are probably the most complex of the three in structure. The thousands of species of bacteria in the world have three different shapes: rod-shaped ones called, bacilli, ball-shaped ones called, cocci, and spiraled ones called spirillum. While that’s what they look like the actual structure is slightly more complex. Things that all bacteria have are: a cell wall to protect itself from the outside environment, plasma to hold all the internal structures it has, ribosomes to produce proteins, flagella to move around, a conjugation pilus to reproduce sexually rather than asexually, fimbriae to help them attach to surfaces, and like all other organisms, bacteria have deoxyribonucleic acid or DNA to provide information for protein formation and reproduction.
It also has a protein coat that holds the nucleic acid. Most viruses are held together by an envelope made of fat and protein molecules. Bacteria consist of DNA, RNA, proteins, polysaccharides, and phospholipids or a combination of something involving those. The macromolecules are made of amino acids, sugars, and nucleotides. Prions on the other hand do not contain any DNA or RNA.
They are not typical of a prokaryotic organism or a eukaryotic organism, all that is present in this pathogen is the protein PrPSc. This is the mutated form of the protein PrPC, which is encoded by a chromosomal gene. These two proteins differ in their spatial protein structures and their susceptibility to enzyme digestion. PrPC is completely destroyed in enzyme digestion, whereas PrPSc is resistant to any form of digestion.Viruses usually have nucleic acid, protein, and other constituents that aid in the creation of more progeny viruses. As far as prions are concerned, they multiply by infecting the PrPC protein and turning it into a complex such as itself, the PrPSc protein.