State two differences in structure between viruses and bacteria.

Describe two ways in which antiviral drugs work.

Discuss two difficulties associated with the development of drugs for the effective treatment of AIDS.

viruses do not have cell/cellular structure;

viruses do not have nucleus;

viruses do not have cell wall;

viruses do not have cytoplasm;

Accept opposite statements for bacteria.

stops virus replication;

Accept reproduction / multiplication.

becomes part of DNA of virus / alters virus DNA / blocks polymerase which builds DNA;

changes the cell membrane that inhibits the entry of virus into the cells;

prevents viruses from leaving the cell (after reproducing);

HIV mutates (rapidly);

Accept AIDS mutates

HIV metabolism linked to that of host cell / HIV uses host cell / drugs harm host cell as well as HIV / difficult to target HIV without damaging host cell;

HIV destroys helper cells of the immune system;

Many students failed to note that the first part of the question referred to structural differences between viruses and bacteria, rather than more general differences. The mode of action of antiviral drugs appeared to be poorly understood and answers were often very vaguely expressed, as were answers to why effective AIDS treatment is such a problem.

Many students failed to note that the first part of the question referred to structural differences between viruses and bacteria, rather than more general differences. The mode of action of antiviral drugs appeared to be poorly understood and answers were often very vaguely expressed, as were answers to why effective AIDS treatment is such a problem.

Many students failed to note that the first part of the question referred to structural differences between viruses and bacteria, rather than more general differences. The mode of action of antiviral drugs appeared to be poorly understood and answers were often very vaguely expressed, as were answers to why effective AIDS treatment is such a problem.