Viruses Flashcards
What glycoprotein(s) is found on the surface of HIV cell membrane?
gp120 and gp41
What does gp120 bind to on target cell’s curface membrane?
CD4 receptor
How many strands of DNA/RNA found in H1N1 and HIV virus respectively? State if the DNA/RNA is positive or negative.
8 negative single-stranded RNA and 2 positive single-stranded RNA
What does H1N1 has on its cell surface membrane?
Haemagglutinin and Neuraminidase
What does haemagglutinin bind to?
Sialic Acid Receptor
How does H1N1 enter target cell?
Endocytosis
How does HIV enter target cell?
Fusion of viral envelope with host cell membrane
What does HIV protease do?
It cleaves polyproteins coded by mRNA into individual proteins
Describe the role of reverse transcriptase in HIV.
Viral reverse transcriptase catalyses the conversion of RNA into DNA using the viral RNA strand as a template.
State the 2 possible life cycles of phages.
Lytic and lysogenic life cycles
How does bacteriophages inject DNA in to target cell?
bacteriophage tail releases an enzyme, phage lysozyme, which digests the bacterial cell wall allowing moleuclues to be released. When molecules interact with virus, it triggers change in the shape of the base plate, initiating a contraction of the phage tail sheath, thrusting the hollow core tube through cell wall. Upon contact with plasma membrane, DNA is injected into bacterial cell.
State the name of the process where lysogenic life cycle changes to a lytic life cycle.
Spontaneous induction
What are the 2 types of phages?
Temperate and lytic phage
What kind of life cycle does T4 bacteriophage have?
Lytic life cycle
What kind of life cycle does lambda phage have?
Lysogenic life cycle
