Everything you need to know about viruses. Some of the frequently asked questions are as follows:- Q.1. Are enzymes found in virions? Give examples. Ans. Some virions contain enzymes which help them in infecting their hosts and to carry on their metabolic activities inside their host, e.g., HIV a retrovirus is an RNA virus which replicates inside the cells of [...]
The life cycle of HIV consists of following steps. They are:- 1. Entry 2. Reverse Transcription and Integration 3. Transcription and Translation 4. Assembly, Budding and Maturation. Step # 1. Entry: Virus binds to the host cells by attaching its Gp 120 to the host cell receptor. CD4 molecule present on T lymphocytes is a predominant receptor. Entry of virus [...]
The following points highlight four important ways by which HIV devastates the immune system. The ways are: 1. Direct killing 2. Apoptosis 3. Destruction of un-infected cells 4. Destruction of immune precursor cells. Way # 1. Direct killing: When a large number of viruses is produced and buds out from the surface of CD4+ T cell surface, the cell membrane [...]