The outer structure surrounding the capsid of some viruses is called the viral envelope. All viruses use some sort of glycoprotein to attach to their host cells at molecules on the cell called viral receptors.
What do viruses use to attach to their host?
Prior to entry, a virus must attach to a host cell. Attachment is achieved when specific proteins on the viral capsid or viral envelope bind to specific proteins called receptor proteins on the cell membrane of the target cell.
What structures do viruses have to attach to a cell?
Many viruses use some sort of glycoprotein to attach to their host cells via molecules on the cell called viral receptors. For these viruses, attachment is a requirement for later penetration of the cell membrane, allowing them to complete their replication inside the cell.
Which is most important for attachment of a virus to a host cell?
The viral attachment protein can be viewed as the “key” that unlocks host cells by interacting with the “lock”—the receptor—on the cell surface, and these lock-and-key interactions are critical for viruses to successfully invade host cells.
Why must viruses attach to receptors to enter cells?
Because the virus-receptor interaction is essential for viral replication, host cells with a mutation in the receptor gene that prevents virus infection survive and eventually dominate the population. A virus could overcome this block with an amino acid change allowing binding to the altered receptor.
What is the basic structure of a virus?
Viruses are much smaller than bacteria and consist of a single- or double-stranded nucleic acid (DNA or RNA) surrounded by a protein shell called a capsid; some viruses also have an outer envelope composed of lipids and proteins. They vary in shape. The two main classes are RNA viruses and DNA viruses.
What structures are found in all viruses?
All viruses contain nucleic acid, either DNA or RNA (but not both), and a protein coat, which encases the nucleic acid. Some viruses are also enclosed by an envelope of fat and protein molecules. In its infective form, outside the cell, a virus particle is called a virion.
What is the general structure of a virus quizlet?
1. Describe the general structure of a virus. Nucleic acid (DNA or RNA) surrounded by a protein coat called a capsid. Virus may be naked or enveloped.
Penetration: The process of attachment to a specific receptor can induce conformational changes in viral capsid proteins, or the lipid envelope, that results in the fusion of viral and cellular membranes. Some DNA viruses can also enter the host cell through receptor-mediated endocytosis.
Which structure on the influenza virus provides attachment to the surface of the targeted host cell?
The glycoprotein responsible for attachment on the surface of an influenza viral particle is hemagglutinin (HA). HA is an antigenic glycoprotein. It is responsible for binding the virus to the cell that is being infected.
What is the main way that viruses replicate?
There are two processes used by viruses to replicate: the lytic cycle and lysogenic cycle. Some viruses reproduce using both methods, while others only use the lytic cycle. In the lytic cycle, the virus attaches to the host cell and injects its DNA.
How do viruses attach to target cells quizlet?
All viruses use some sort of glycoprotein to attach to their host cells at molecules on the cell called viral receptors. The virus exploits these cell-surface molecules, which the cell uses for some other purpose, as a way to recognize and infect specific cell types.
What type of receptor does influenza virus bind?
Sialic acids (SAs) of cell surface glycoproteins and glycolipids are the receptors for the influenza virus, recognized by the viral glycoprotein hemagglutinin (HA; Figure 1). The site on HA at which the cellular receptors are bound is at the distal end of the molecule.
How do viruses enter the cell through endocytosis?
Endocytic entry of viruses occurs in a stepwise manner involving attachment to the cell surface, clustering of receptors, activation of signaling pathways, formation of endocytic vesicles and vacuoles, delivery of viral cargo to endosomal compartments, sorting, and escape into the cytosol.
What is the mechanism by which a virus attaches to a membrane receptor protein?
Attachment to host cell is mediated by virion protein(s) binding to specific host surface molecule(s) such as membrane proteins, lipids, or the carbohydrate moieties present either on glycoproteins or glycolipids . The cell biology of receptor-mediated virus entry.