Why are naked viruses generally more resistant to disinfectants than are enveloped viruses? Naked viruses usually lack a viral envelope that covers their protective protein capsids. Most pages are examples of naked viruses. On the other hand, enveloped viruses contain an envelope or outer wrapping. The infectivity of such enveloped viruses is mainly dependent on the envelope. They require that their envelope and attachment spikes to be infectious. HIV is an example of an enveloped virus. Naked viruses are more tolerant to disinfectants as compared to enveloped viruses because disinfectants usually damage the viral envelope of the viruses by disrupting the lipid layer rendering the virus non-infectious. They also alter the mechanism by which the viruses attack and infect their hosts. Lipid envelopes are usually quite sensitive and can be easily damaged by disinfectants such as ethanol and propanol alcohols. Since naked viruses do not have such a lipid envelope, they are more resistant to disinfectants and they also have a protein capsid which is resistant and in nature.
Create a chart outlining the difference between prions, viruses and viroids.
Prions are very small protein particles that are infectious. They have neither DNA nor RNA. Prions can cause infections to both humans and animals. Prions are usually undetectable as they are a part of the biochemistry of the host. Prions are known to cause neurodegenerative brain infections.
Viruses are intracellular infective agents which consist of nucleic acid and protein. They contain DNA or RNA but never both. Viruses can only multiply when they are within the living cells of a host. They can cause infections to all types of living organisms. Viruses cause infections such as flu and common cold by replicating themselves in the cell of the host.
Viroids are circular and small pieces of RNA which are pathogenic and cause infections only to plants. They are considered to be incomplete viruses that lack a protein coat. Viroids affect plant life by affecting the ability of the plant to produce the essential proteins required.
Create a chart comparing and contrasting the replication strategies of DNA viruses, RNA viruses, and reverse-transcribing viruses.
DNA viruses have to enter the nucleus of the host before they can have the ability to replicate as they do not have an RNA polymerase gene which is found in the nucleus. DNA viruses have DNA as their genetic material. They use a copying mechanism that uses DNA polymerase in replication. An example of a DNA virus is the herpes virus.
RNA viruses mostly replicate in the cytoplasm. They use virally encoded RNA-dependent RNA-polymerase to replicate their genomes. The genome is translated into protein produces by producing messenger RNA (mRNA). An example of an RNA virus is the mouse hepatitis virus.
Reverse-transcribing viruses replicate using a process referred to as reverse transcription. DNA is made from RNA templates. An enzyme is used in which RNA genomes are reverse transcribed into DNA. Examples include the hepadnaviruses.