orrectly label the following anatomical features of an HIV structure. Matrix Reverse Envelope Capsid Glycoprotein Phospholipid RNA transcriptase
The Correct Answer and Explanation is:
Correctly Labeled HIV Structure
Here is the image with all the anatomical features correctly labeled:
Explanation of HIV Anatomy
The Human Immunodeficiency Virus (HIV) is a complex retrovirus responsible for causing Acquired Immunodeficiency Syndrome (AIDS). Its structure is meticulously organized to facilitate its primary function: infecting host cells, typically CD4+ T-helper lymphocytes, and replicating. Understanding its anatomy is crucial for developing effective antiretroviral therapies.
- Envelope: The outermost layer of the virion is the Envelope, a lipid bilayer derived from the host cell’s plasma membrane as the new virus particle buds off. This envelope contains two critical components:
- Phospholipid: These molecules form the basic structure of the envelope’s bilayer, creating a barrier that encapsulates the viral components.
- Glycoprotein: Embedded within and protruding from the envelope are viral glycoproteins (specifically gp120 and gp41). These protein spikes are essential for the virus to identify and bind to specific receptors (like the CD4 receptor and a coreceptor such as CCR5 or CXCR4) on the surface of a host cell, initiating the process of infection.
- Matrix: Located just beneath the envelope is a protein layer called the Matrix. Composed primarily of the p17 protein, the matrix provides structural integrity to the virion, linking the envelope to the viral core. It also plays a key role during the assembly and budding stages of the viral life cycle.
- Capsid: At the center of the virus is the Capsid, a cone- or bullet-shaped protein shell made from the p24 protein. The primary function of the capsid is to protect the virus’s most vital contents: its genetic material and essential enzymes. Upon entry into a host cell, the capsid disassembles in a process called uncoating, releasing its contents into the cytoplasm.
- RNA: Inside the capsid lies the genetic material of HIV. Unlike organisms that use DNA, HIV’s genome consists of two identical single-stranded RNA molecules. This RNA contains all the genetic information required to produce new virus particles.
- Reverse Transcriptase: Packaged alongside the RNA within the capsid is a crucial viral enzyme called Reverse Transcriptase. As a retrovirus, HIV uses this enzyme to perform a unique process: it synthesizes a double-stranded DNA copy from its RNA template. This newly formed viral DNA is then transported into the host cell’s nucleus and integrated into the host’s own genome, effectively hijacking the cell’s machinery to replicate the virus. Other enzymes, such as integrase and protease, are also present but not labeled in this diagram.
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