Podcast
Questions and Answers
One classification scheme was developed in the 1970s by Nobel laureate ______.
One classification scheme was developed in the 1970s by Nobel laureate ______.
David Baltimore
______ classification system categorizes viruses based on the type of nucleic acid genome and replication strategy of the virus.
______ classification system categorizes viruses based on the type of nucleic acid genome and replication strategy of the virus.
Baltimore
Positive-strand RNA is able to be immediately translated into ______.
Positive-strand RNA is able to be immediately translated into ______.
proteins
Negative-strand RNA is not translatable into ______; it first has to be transcribed into positive-strand RNA.
Negative-strand RNA is not translatable into ______; it first has to be transcribed into positive-strand RNA.
Viruses are only classified using ______, family, genus, and species.
Viruses are only classified using ______, family, genus, and species.
The suffix for an order of viruses is ______.
The suffix for an order of viruses is ______.
The suffix for a family of viruses is ______.
The suffix for a family of viruses is ______.
The suffix for a genus of viruses is ______.
The suffix for a genus of viruses is ______.
Viruses are categorized based upon their type of ______ acid.
Viruses are categorized based upon their type of ______ acid.
The ______ virus causes the decline of the immune system, leading to immunodeficiency.
The ______ virus causes the decline of the immune system, leading to immunodeficiency.
The ______ virus gets its name from the Latin word for 'crown', referring to the crown-like appearance of the virions.
The ______ virus gets its name from the Latin word for 'crown', referring to the crown-like appearance of the virions.
The ______ virus was named after the Ebola River in northern Democratic Republic of the Congo.
The ______ virus was named after the Ebola River in northern Democratic Republic of the Congo.
The ______ virus was named after Michael Anthony Epstein and Yvonne Barr, who discovered the virus.
The ______ virus was named after Michael Anthony Epstein and Yvonne Barr, who discovered the virus.
A virus must undergo the process of ______ to create new, infectious virions.
A virus must undergo the process of ______ to create new, infectious virions.
The ______ stage of virus replication involves the release of the viral genome from the capsid.
The ______ stage of virus replication involves the release of the viral genome from the capsid.
The final stage of virus replication is ______, where the virions are released from the cell to continue the process of infection.
The final stage of virus replication is ______, where the virions are released from the cell to continue the process of infection.
Phagocytosis is a form of ______ endocytosis that is used by specialized cells to engulf entire cells.
Phagocytosis is a form of ______ endocytosis that is used by specialized cells to engulf entire cells.
Fusion of the viral envelope can occur at the ______ membrane or within endocytosed vesicles, such as the endosome.
Fusion of the viral envelope can occur at the ______ membrane or within endocytosed vesicles, such as the endosome.
Clathrin-mediated ______ is used by viruses such as dengue virus, hepatitis C virus, and reovirus.
Clathrin-mediated ______ is used by viruses such as dengue virus, hepatitis C virus, and reovirus.
Caveolin-mediated ______ is used by viruses such as human papillomavirus and hepatitis B virus.
Caveolin-mediated ______ is used by viruses such as human papillomavirus and hepatitis B virus.
Fusion is a type of penetration method used by viruses such as HIV, influenza, and ______.
Fusion is a type of penetration method used by viruses such as HIV, influenza, and ______.
Uncoating refers to the breakdown or removal of the ______, causing the release of the virus genome into the cell.
Uncoating refers to the breakdown or removal of the ______, causing the release of the virus genome into the cell.
Rhinoviruses are taken into the cell by ______ endocytosis in clathrin-coated vesicles.
Rhinoviruses are taken into the cell by ______ endocytosis in clathrin-coated vesicles.
Poliovirus releases its RNA genome into the ______ through a pore in the cell membrane.
Poliovirus releases its RNA genome into the ______ through a pore in the cell membrane.
Virus attachment is the binding of the virus to the host ______.
Virus attachment is the binding of the virus to the host ______.
Rhinovirus binds to a protein known as ______ (ICAM-1).
Rhinovirus binds to a protein known as ______ (ICAM-1).
Influenza A virus strains bind to the ______ acid sugars found at the ends of cellular carbohydrate chains.
Influenza A virus strains bind to the ______ acid sugars found at the ends of cellular carbohydrate chains.
HIV initially binds to a protein known as ______ on the surface of T lymphocytes.
HIV initially binds to a protein known as ______ on the surface of T lymphocytes.
Penetration refers to the crossing of the ______ membrane by the virus, following attachment.
Penetration refers to the crossing of the ______ membrane by the virus, following attachment.
Most types of viruses use ______-mediated endocytosis to enter the cell.
Most types of viruses use ______-mediated endocytosis to enter the cell.
Papillomaviruses use ______-mediated endocytosis to enter the cell.
Papillomaviruses use ______-mediated endocytosis to enter the cell.
Bulk-phase endocytosis is the process where the cell forms a vesicle that engulfs whatever molecules are present in the ______ fluid.
Bulk-phase endocytosis is the process where the cell forms a vesicle that engulfs whatever molecules are present in the ______ fluid.
Recombination occurs when the genome of an RNA virus is being replicated and the RdRp jumps from the template of one strain to the template of the other strain, creating a hybrid ______.
Recombination occurs when the genome of an RNA virus is being replicated and the RdRp jumps from the template of one strain to the template of the other strain, creating a hybrid ______.
Reassortment occurs when the genome segments of ______ viruses are mixed while being packaged into new capsids.
Reassortment occurs when the genome segments of ______ viruses are mixed while being packaged into new capsids.
Viruses components must be collected at a particular site of the cell and undergo ______ to form an immature virus particle.
Viruses components must be collected at a particular site of the cell and undergo ______ to form an immature virus particle.
Most nonenveloped DNA viruses assemble their nucleocapsid in the ______, since that is the site of genome replication.
Most nonenveloped DNA viruses assemble their nucleocapsid in the ______, since that is the site of genome replication.
Viruses with envelopes derived from the plasma membrane usually assemble at the ______.
Viruses with envelopes derived from the plasma membrane usually assemble at the ______.
Maturation refers to the final changes within an immature ______.
Maturation refers to the final changes within an immature ______.
For enveloped viruses, the final step of release involves ______ from the plasma membrane.
For enveloped viruses, the final step of release involves ______ from the plasma membrane.
Nonenveloped viruses can also exit the cell via ______.
Nonenveloped viruses can also exit the cell via ______.
Study Notes
Virus Classification and Taxonomy
- The Baltimore classification system categorizes viruses based on the type of nucleic acid genome and replication strategy.
- Positive-strand RNA viruses can be immediately translated into proteins, while negative-strand RNA viruses must be transcribed into positive-strand RNA first.
- Viruses are classified using the taxa: order, family, genus, and species.
Taxa Used to Classify Viruses
- Order: ends in the -virales suffix, with only about half of viruses currently classified in orders (e.g., Picornavirales).
- Family: ends in the -viridae suffix, with subfamilies indicated by the -virinae suffix (e.g., Picornaviridae).
- Genus: ends in the -virus suffix (e.g., Enterovirus).
- Species: the "common name" of the virus (e.g., Rhinovirus A).
Name Origins of Viruses
- Viruses can be named after the clinical conditions they cause (e.g., Human immunodeficiency virus, Hepatitis virus).
- Viruses can be named after their properties (e.g., Coronavirus, Herpesviruses).
- Viruses can be named after their location of discovery (e.g., Ebola virus).
- Viruses can be named after people (e.g., Epstein-Barr virus).
Virus Replication
- The seven stages of virus replication are: attachment, penetration, uncoating, replication, assembly, maturation, and release.
- Attachment: the binding of the virus to the host cell, which is specific and involves the virus attachment protein and cell surface receptor.
- Penetration: the crossing of the plasma membrane by the virus, which can occur through receptor-mediated endocytosis, bulk-phase endocytosis, phagocytosis, or fusion.
Penetration Methods
- Clathrin-mediated endocytosis (e.g., dengue virus, hepatitis C virus).
- Caveolin-mediated endocytosis (e.g., human papillomavirus, hepatitis B virus).
- Fusion (e.g., HIV, influenza, respiratory syncytial virus).
Uncoating
- The breakdown or removal of the capsid, releasing the virus genome into the cell.
- Can be separated from or tightly linked with penetration.
- Examples: rhinoviruses, poliovirus.
Assembly
- The collection of virus components at a specific site of the cell and assembly into an immature virus particle.
- Can occur in the nucleus, at the plasma membrane, or at intracellular membranes.
- Examples: non-enveloped DNA viruses (e.g., assemble in the nucleus), viruses with envelopes derived from the plasma membrane.
Maturation
- The final changes within an immature virion, involving structural capsid changes.
- Example: influenza HA protein must be cleaved into two portions (HA1 and HA2) to become infectious.
Release
- The final step of virus replication, involving the exit of the mature virion from the host cell.
- Enveloped viruses can bud from the plasma membrane and undergo exocytosis to leave the cell.
- Non-enveloped viruses can exit the cell via exocytosis or lyse the cell.
- Examples: lytic viruses, which disrupt the plasma membrane and cause cell lysis.
Studying That Suits You
Use AI to generate personalized quizzes and flashcards to suit your learning preferences.
Related Documents
Description
This quiz covers the classification and replication of viruses, including the Baltimore classification system and the types of nucleic acid genome and replication strategies.
