Question

During viral infection, attachment is usually specific to a particular cell type because a the virus is attracted to the appropriate host cells by proteins secreted into the extracellular fluid. b. the virus recognizes and binds to specific molecules in the cytoplasm of the host cell. c. the virus recognizes and binds to specific molecules on the surface of the host cell. d. the host cell produces channel proteins that provide passageways for viruses to enter the cytoplasm. e. the virus releases specific proteins that make holes in the membrane large enough for the virus to enter.

Short answer

The correct answer is c. The virus recognizes and binds to specific molecules on the surface of the host cell.

Step-by-step solution

Understand the virus-cell interaction

Virus-cell interaction is the process by which a virus recognizes and binds to its host cell. Viruses are unable to replicate by themselves and need host cells to do this. That's hence the first step a virus needs to perform - finding and binding a suitable host cell.

Evaluate the possible answers

Look at each option carefully. Most of them talk about an interaction between the virus and the host cell, either at the surface level or within the cytoplasm, and how the virus enters the cell. It is necessary to understand whether these proposed interactions reflect the actual biochemistry of virus-cell binding.

Determine the correct option

The correct answer is the one that correctly describes the specific binding between viruses and their host cells. The specific molecules that a virus recognizes and binds to are located at the host cell's surface, not inside the cell, making option c the correct response.

Key concepts

Virus-Cell Interaction

The concept of virus-cell interaction refers to the manner in which viruses engage with host cells. This interaction is fundamental to a virus's ability to invade and take over the cellular machinery for its replication. Viruses strategically identify cells that can facilitate their multiplication due to their well-matched surface receptors. Each step of the viral lifecycle, from attachment to entry and subsequent replication, is critically dependent on this initial interaction. To clarify, viruses have evolved to be highly specific to the cells they infect. Specificity is determined by the cell surface molecules that the virus can bind to, known as receptors. Once a virus identifies potential host cells, it will bind to these specific receptors, setting the stage for infection. Understanding these interactions is crucial in developing therapeutic strategies to block viral entry into cells.

Host Cell Binding

Host cell binding is an essential step in the viral infection process. This refers to the virus making a physical connection with the host cell’s surface, leveraging specific molecular interactions. A virus comes equipped with special proteins or glycoproteins on its surface, designed to latch onto matching receptors on the host cell. During this binding:

• The viral surface proteins recognize and adhere to the receptor molecules on the host cell surface.
• This specificity ensures that the virus attaches only to certain kinds of cells, a process crucial for targeting specific tissues or organisms.
• The strong molecular fit between the virus and these receptors allows the virus to initiate entry into the host cell.

This binding isn't a one-size-fits-all process, as each virus may target different receptors, dictating which cells can be infected and which cannot. Through understanding these intricate molecular interactions, scientists strive to design treatments that block this binding stage, potentially preventing infection altogether.

Viral Attachment

Viral attachment is the initial step in the infection process, connecting the virus to a host cell. This phase is vital because it sets the entire infection process into motion. The attachment involves precise contacts between the viral particles and specific proteins or sugars on the host cell surface. Key aspects of viral attachment involve:

• The virus's affinity for particular cell surface structures.
• Viral proteins or glycoproteins using their unique shapes to fit precisely with their target receptors.
• Changing the host cell's surface properties to enable subsequent viral entry.

Importantly, viruses like the influenza virus or HIV have specialized proteins that play primary roles in this attachment process. These proteins are often the target of antiviral drugs, as disabling them can halt the infection at its earliest stage. Successfully understanding and disrupting viral attachment is a cornerstone in the efforts to manage viral infections.