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Animation: HIV Reproductive Cycle

by Pearson
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HIV Reproductive Cycle. Understanding the structure and life cycle of HIV (Human Immunodeficiency Virus) or the AIDS virus, is critically important to dealing with the disease. HIV is covered by an envelope derived from a host cell membrane. Glycoproteins studding the envelope recognize and bind to receptor molecules on the host cell. A protein coat surrounds the viral genetic material, which consists of two molecules of single-stranded RNA. The enzyme reverse transcriptase enables the virus to make DNA from an RNA template, a trick for which this group of viruses is named as retroviruses. The RNA molecules of HIV enter a host cell when the virus fuses with the plasma membrane and the coat proteins are removed by enzymes. Reverse transcriptase catalyzes the synthesis of a DNA strand complementary to the viral RNA strand and then a second DNA strand complementary to the first. The double-stranded DNA is incorporated as a provirus into the host cell's chromosomal DNA, where it may lie dormant for years. Occasionally, the provirus is transcribed into RNA. This RNA serves as both messenger RNA for the formation of HIV proteins and as genetic material for the next generation of viruses. Protein coats form around viral RNA and reverse transcriptase molecules. Viruses bud from the host cell, acquiring envelopes as they leave.
HIV Reproductive Cycle. Understanding the structure and life cycle of HIV (Human Immunodeficiency Virus) or the AIDS virus, is critically important to dealing with the disease. HIV is covered by an envelope derived from a host cell membrane. Glycoproteins studding the envelope recognize and bind to receptor molecules on the host cell. A protein coat surrounds the viral genetic material, which consists of two molecules of single-stranded RNA. The enzyme reverse transcriptase enables the virus to make DNA from an RNA template, a trick for which this group of viruses is named as retroviruses. The RNA molecules of HIV enter a host cell when the virus fuses with the plasma membrane and the coat proteins are removed by enzymes. Reverse transcriptase catalyzes the synthesis of a DNA strand complementary to the viral RNA strand and then a second DNA strand complementary to the first. The double-stranded DNA is incorporated as a provirus into the host cell's chromosomal DNA, where it may lie dormant for years. Occasionally, the provirus is transcribed into RNA. This RNA serves as both messenger RNA for the formation of HIV proteins and as genetic material for the next generation of viruses. Protein coats form around viral RNA and reverse transcriptase molecules. Viruses bud from the host cell, acquiring envelopes as they leave.