🧫 STRUCTURE OF HIV (A RETROVIRUS)

What is HIV?

• HIV = Human Immunodeficiency Virus
• Belongs to a group called retroviruses.
• Retroviruses contain RNA instead of DNA.

Features of HIV:

• Spherical shape, around 100 nm in size.
• Surrounded by a lipid-rich envelope.
• Has glycoprotein spikes (like keys) that help it bind to human immune cells.

🔄 What Makes Retroviruses Special?

• They have an enzyme called Reverse Transcriptase.

Function of Reverse Transcriptase:

• Converts RNA → DNA (reverse of normal transcription).
• This DNA then becomes part of the host cell’s genetic material.
• Helps virus multiply inside the host.

📌 Normal Flow: DNA → RNA → Proteins
🧬 Retrovirus Flow: RNA → DNA → RNA → Proteins

💡 Mnemonic:
“RDRP” = Retroviruses Do Reverse Process

☠️ HIV and AIDS

What is AIDS?

• AIDS = Acquired Immuno Deficiency Syndrome
• Caused by HIV.
• It damages the immune system, especially the T-cells that fight infections.
• Without a strong immune system, even minor infections become deadly.

⚠️ There is no permanent cure yet, but treatment helps control the infection.

🕰️ HISTORY OF HIV AND AIDS

• 1981: AIDS first reported (initially in homosexual men).
• 1984: Virus identified as the cause.
• 1986: Named HIV (Human Immunodeficiency Virus).

🌍 ORIGIN OF HIV

• HIV is believed to have come from chimpanzees in Africa.
• The virus multiplies in monkeys but does not cause AIDS in them.
• Transmission to humans may have happened through:
  • Bites from infected monkeys
  • Eating monkey meat or brains