MCB4271
MCB4271 Exam 4 Questions with
Detailed Answers 2025
5-substituted 2'- deoxyuridines -Correct Answer ✔Arrest base pairing, originally for
cancer since it stops cellular respiration
Nucleoside/tide Analogues -Correct Answer ✔Inhibit DNA polymerase, Telbivudine,
Entecavir
Pyrophosphate Analogues -Correct Answer ✔Target DNA polymerase by binding
pyrophosphate binding site of DNA polymerase; Fascarnet
Nucleoside Reverse Transcriptase Inhibitors -Correct Answer ✔Target HIV and HBV
reverse transcriptase, need to be phosphorylated to 5'-TP and are chain inhibitors
Nonnucleoside Reverse Transcriptase Inhibitors -Correct Answer ✔Anti HIV-1 but not 2,
target RT by binding near catalytic site and inducing conformational change
Protease Inhibitors -Correct Answer ✔Break up large viral precursor protein, so inhibiting
them stops replication; target HIV or HCV and they mimic the substrate; administered
with other drugs that increase bioavailability and stability
Integrase Inhibitors -Correct Answer ✔Bind catalytic site of HIV integrase and prevent
incorporation of viral DNA into host genome; much more effective than NRTI, NNRTI and
PI
Entry Inhibitors -Correct Answer ✔Membrane fusion, endocytosis, genetic injection;
Biomimetic peptides (Enfuvirtide block virus-host membrane fusion), Receptor
MCB4271
, MCB4271
Antagonists (Maraviroc block host cell surface receptors that interact with viral particles
prior to entry), Neutralizing Antibodies (Palivizumab block viral receptor and prevent
anchoring to host cell), Broad lipid-enveloped virus entry inhibitor (Docosanol is though
to interact with epithelial cell surface inhibitors)
Acyclic Guanosine Analogues -Correct Answer ✔Inhibit viral DNA polymerase, some are
phosphorylated by host kinase while others by viral thymidine kinase; once
phosphorylated they compete with endogenous dGTP to bind and inhibit viral DNA
polymerase (prodrugs)
Acyclic Nucleoside Phosphonate Analogues -Correct Answer ✔Inhibit viral DNA
polymerase and reverse transcription, have PCO linkage which can't be cleaved so it
causes irreversible inhibition of DNA polymerization
HCV NS5A/NS5B Inhibitors -Correct Answer ✔NS5A is essential for HCV genome
replications and NS5B is for HCV RNA polymerase
Influenza virus Inhibitors -Correct Answer ✔Matrix 2 inhibitors (block H+ transport
through M2 ion channels into interior of viral particles which is essential for uncoating...
only effective in adults) and Neuraminidase Inhibitors (viral replication), inhibit GTP
biogenesis
Clinical Mechanisms of Resistance (Viral) -Correct Answer ✔5-substituted 2'-
deoxyuridines have no known mechanisms of resistance against them; drug target
modification by substitution against Nucleoside/tide analogues, NRTIs, NNRTIs, PI
(primary mutation and strong secondary mutation), Integrase Inhibitors, Entry Inhibitors,
Acyclic guanosine analogues, ANP analogues (also have DNA polymerase mutations but
these reduce viral fitness), NS5A and NS5B (also have DNA polymerase mutations,
reduce viral fitness), Flu inhibitors (also have DNA polymerase mutations, which reduce
viral fitness)
MCB4271
MCB4271 Exam 4 Questions with
Detailed Answers 2025
5-substituted 2'- deoxyuridines -Correct Answer ✔Arrest base pairing, originally for
cancer since it stops cellular respiration
Nucleoside/tide Analogues -Correct Answer ✔Inhibit DNA polymerase, Telbivudine,
Entecavir
Pyrophosphate Analogues -Correct Answer ✔Target DNA polymerase by binding
pyrophosphate binding site of DNA polymerase; Fascarnet
Nucleoside Reverse Transcriptase Inhibitors -Correct Answer ✔Target HIV and HBV
reverse transcriptase, need to be phosphorylated to 5'-TP and are chain inhibitors
Nonnucleoside Reverse Transcriptase Inhibitors -Correct Answer ✔Anti HIV-1 but not 2,
target RT by binding near catalytic site and inducing conformational change
Protease Inhibitors -Correct Answer ✔Break up large viral precursor protein, so inhibiting
them stops replication; target HIV or HCV and they mimic the substrate; administered
with other drugs that increase bioavailability and stability
Integrase Inhibitors -Correct Answer ✔Bind catalytic site of HIV integrase and prevent
incorporation of viral DNA into host genome; much more effective than NRTI, NNRTI and
PI
Entry Inhibitors -Correct Answer ✔Membrane fusion, endocytosis, genetic injection;
Biomimetic peptides (Enfuvirtide block virus-host membrane fusion), Receptor
MCB4271
, MCB4271
Antagonists (Maraviroc block host cell surface receptors that interact with viral particles
prior to entry), Neutralizing Antibodies (Palivizumab block viral receptor and prevent
anchoring to host cell), Broad lipid-enveloped virus entry inhibitor (Docosanol is though
to interact with epithelial cell surface inhibitors)
Acyclic Guanosine Analogues -Correct Answer ✔Inhibit viral DNA polymerase, some are
phosphorylated by host kinase while others by viral thymidine kinase; once
phosphorylated they compete with endogenous dGTP to bind and inhibit viral DNA
polymerase (prodrugs)
Acyclic Nucleoside Phosphonate Analogues -Correct Answer ✔Inhibit viral DNA
polymerase and reverse transcription, have PCO linkage which can't be cleaved so it
causes irreversible inhibition of DNA polymerization
HCV NS5A/NS5B Inhibitors -Correct Answer ✔NS5A is essential for HCV genome
replications and NS5B is for HCV RNA polymerase
Influenza virus Inhibitors -Correct Answer ✔Matrix 2 inhibitors (block H+ transport
through M2 ion channels into interior of viral particles which is essential for uncoating...
only effective in adults) and Neuraminidase Inhibitors (viral replication), inhibit GTP
biogenesis
Clinical Mechanisms of Resistance (Viral) -Correct Answer ✔5-substituted 2'-
deoxyuridines have no known mechanisms of resistance against them; drug target
modification by substitution against Nucleoside/tide analogues, NRTIs, NNRTIs, PI
(primary mutation and strong secondary mutation), Integrase Inhibitors, Entry Inhibitors,
Acyclic guanosine analogues, ANP analogues (also have DNA polymerase mutations but
these reduce viral fitness), NS5A and NS5B (also have DNA polymerase mutations,
reduce viral fitness), Flu inhibitors (also have DNA polymerase mutations, which reduce
viral fitness)
MCB4271
