The virus then finds the protein by using the nucleic acid. Several new RNA or DNA strands are made. Once the cell has exceeded the maximum number of strands, it then bursts open and the new particles find new host cells. The process is then repeated.3 The following is a list of the many ways viruses can be classified: 1.) Whether viral particles contain RNA or DNA strands.
Viruses: Complex Molecules or Simple Life Forms? Viruses have been defined as "entities whose genomes are elements of nucleic acid that replicate inside living cells using the cellular synthetic machinery, and cause the synthesis of specialised elements that can transfer the genome to other cells." They are stationaryand are unable to grow. Because of all these factors, it is debatable whether viruses are the most complex of molecules or the simplest life forms. While the definition of living organisms must be adapted, the majority of evidence leads to the classification of viruses as living organisms.
The capsid has three functions; one is to protect the nucleic acid from digestion by the enzymes. Another is that it has special sites on its surface that allows the virion to attach to the host cell. The third function is that it provides proteins for the virion to penetrate the host cell membrane. The virus ‘glycoprotein envelope, surrounds the nucleocapsid. The envelope has two lipid layers with protein molecules interspersed.
Viruses have either DNA or RNA, but not both, a protein coat that incases the nucleic acid, and some even have a nuclear envelope. Sometimes viruses have spikes that they use to attach onto their host. Viruses undergo the lytic and lysogenic cycles when they reproduce. The lytic cycle goes through five stages: attachment, penetration, biosynthesis, maturation, and release. According to Essentials of Biology, “During attachment the capsid combines with a receptor in the bacterial cell wall.
Once the virus is in the cell, it then uncoats itself freeing viral genes and enzymes. After the uncoating stage the virus then goes through the fourth stage, called reverse transcription, in this stage copies of viral RNA and DNA are produced. Once the DNA is copied it then enters the nucleus of the cell and undergoes what is called genome integration where the viral integrase splices viral DNA into cellular DNA. Once the cellular DNA is made, the cell then uses the new DNA as a template for reproducing the HIV RNA genome.
The general structure of HSV-1 consists of an envelope, glycoproteins, icosahedral capsid, and linear dsDNA in the center. The envelope is covered with viral glycoproteins, gC and gD, that bind to heparin-sulfate receptors on the cell surface to initiate infection4. Within the envelope is the tegument which links the envelope to the capsid. The tegument also contains proteins and mRNAs that are ready to disrupt cellular processes. Within the center of the HSV-1 structure is the icosahedral capsid that protects the linear dsDNA inside4.
See a diagram depicting this process. Some of the different types of viruses used as gene therapy vectors: Retroviruses - A class of viruses that can create double-stranded DNA copies of their RNA genomes. These copies of its genome can be integrated into the chromosomes of host cells. Human immunodeficiency virus (HIV) is a retrovirus. Adenoviruses - A class of viruses with double-stranded DNA genomes that cause respiratory, intestinal, and eye infections in humans.
In The bacteria cell, the DNA is present in the plasmid whilst in the virus the DNA is present in the capsid. Also, both cells use their DNA to take a key role in their replication. Viruses inject it into host cells an tricks them into replication whilst the prokaryotic bacteria cell replicates its genetic material an splits into daughter cells. In contrast, the Virus has a lipid bilayer as oppose to the phospholid bilayer of the bacterial
Once the virus is inside a cell, the RNA is transcribed and replicated. The RNA is transcribed, producing mRNA which are used to produce the virus' proteins. The RNA is replicated in the cytoplasm and is mediated by the synthesis of an antisense positive RNA strand which serves as a template for producing additional Ebola genomes. As the infection progresses, the cytoplasm develops "prominent inclusion bodies" which means that