Reference no: EM133933959

Question

"Noncellular infectious agents, also referred to as acellular, lack most components of a cell such as ribosomes, plasma membrane, and organelles. The non-cellular structure is mainly composed of nucleic acid engulfed in a protein coat known as a capsid. The two types of organisms that meet these criteria are viruses which are organic molecules consisting of some short strands of either RNA or DNA as their genome within a protein coat. Viruses can reproduce independently through the lytic life cycle, capable of mutating and adapting, are parasitic, and are able to convert raw materials to produce energy. An example of a noncellular agent is a Prion, which are neither bacterial nor fungal, and believed to be the smallest disease-causing agent. Prions do not contain nucleic acid; they are composed of α-helixes that convert normal protein with a normal folding curve to an abnormal form which resist to breakdown by the cellular enzyme proteases. In first method, it will explain how prions damages humans. Another example is a viroid, an infectious single stranded RNA organism which consists of 246-463 nucleotides they are the smallest pathogenic agents found even smaller than a single virus. There are thirty-three different viroids causing diseases in their host for example in humans hepatitis D is caused by when a hepatitis B virus latches onto the host cell and viroid is transported into the cell where there is a simultaneous infection of the cell with both the virus and viroid. Also infects mammals allowing it to infect the host (potatoes and tomatoes) by the rolling circle mechanism by three stages that need to be met, the Synthesized strand of nucleotides catalysed by two enzymes, the RNA is then mediated by hammerhead ribozymes and the last stage is circularization."