78. VIRUS REPLICATION IN THE HOST CELL Flashcards
- Name 3 examples of Single Stranded RNA (ss RNA) Viruses.
- Positive Sense RNA Genome Viruses
- they have a 5’ - 3’ RNA orientation
- they go in the same direction as the mRNA - Negative Sense RNA Genome Viruses
- they have a 3’ - 5’ RNA orientation
- they go in the opposite direction of the mRNA - Retroviruses
- they have their own type of Replication M echanism
- When it comes to DNA Viruses, how are they replicated in the host cells?
DNA VIRUSES:
- use the same replication mechanism as the host cell
BOTH SINGLE STRANDED AND DOUBLE STRANDED DNA VIRUSES:
- replicate using the host cell’s DNA Polymerase Enzyme
THE VIRAL DNA (SS OR DS):
- will use to host cells DNA Polymerase enzyme
- the viral DNA will replicate itself
- it will form multiple copies of the DNA (cDNA)
- When it comes to RNA Viruses, how are they replicated in the host cells?
RNA VIRUSES:
- use different replication mechanisms than the host cell
- When it comes to Single Stranded RNA Viruses, how are they replicated in the host cells?
SINGLE STRANDED RNA VIRUSES (RETROVIRUSES):
- will use Reverse Transcriptase
- this is a viral enzyme
- this will convert the RNA into multiple copies of viral
DNA (cDNA)
THE VIRAL COPIES OF THE DNA (CDNA):
- will be exposed to the host cell’s RNA polymerase
- this will convert the cDNA into a copy of the viral RNA
- When it comes to other kinds of RNA Viruses that are not single stranded, how are they replicated in the host cells?
SINGLE STRANDED RNA VIRUSES (RETROVIRUSES):
- will use an RNA-dependent RNA Polymerase
- this is a viral enzyme
- this enzyme uses RNA as a template to produce more
RNA
THE VIRAL RNA:
- will be exposed to the RNA-dependent RNA
polymerase found in the virus
- this will convert the viral RNA into a copy of the viral
RNA
- Which process is the complete opposite of
RNA-dependent RNA polymerase?
- Normal Transcriptase
- this is when the DNA is converted to RNA
IN THE CASE OF RNA-DEPENDENT RNA POLYMERASE:
- the RNA is converted to more RNA
- What happens when the Viral Nucleic Acid (Virus) undergoes Transcription and Translation?
- it produces Viral Proteins
- When it comes to DNA Viruses, how do they undergo Transcription and Translation?
TRANSCRIPTION:
- the viral DNA
- produces viral mRNA
- it does this by using RNA Polymerase
- the RNA Polymerase is an enzyme from the host cell
TRANSLATION:
- the viral mRNA
- will be exposed to Ribosomes in the host cell
- this will produce Viral proteins in the host cell
- What two functions does the RNA Virus serve?
- THE VIRAL RNA SERVES AS MRNA
- this happens in the case of Positive Sense RNA Viruses
- these are viruses with a 5’-3’ Orientation - THE VIRAL RNA SERVES AS A TEMPLATE
- the viral RNA will make use of the RNA-dependent
RNA Polymerase from the virus
- this template is used to produce viral mRNA
- this happens in the case of Negative Sense RNA
Viruses
- these are viruses that have a 3’-5’ Orientation
- When it comes to RNA Viruses, how does Translation happen?
- the viral mRNA is exposed to Ribosomes in the Host
Cell - the viral mRNA is converted into Viral Protein
- this is done through the Translation Machinery of the
Host Cell
- Provide a description for Label 1.
- the Non-Enveloped Virus Enters the Host cell
- the virus is then uncoated
- Provide a description for Label 2.
- the virus is Replicated in the cell
- Provide a description for Label 3.
- the virus undergoes Transcription
- this produces viral capsid proteins
- Provide a description for Label 4.
- the new virus proteins will assemble by themselves
- they will exit the Host Cell
- Provide a description for Label 1.
- this is a Capsid
- it is an enveloped RNA virus
- the envelope is made up of Glycoproteins
- Provide a description for Label 2.
- the Capsid and the Viral Genome enter the Host Cell
- Provide a description for Label 3.
- the RNA undergoes replication using the
RNA-dependent RNA Polymerase enzyme - this is found in the virus
- Provide a description for Label 4.
- a new virus is released from the Host Cell
