Pech's Blog entry #13

This week, we've discussed the topic of viruses. Many have debated whether or not viruses are alive, but I think that viruses are alive because viruses are consider prokaryotic cell and they are constantly growing and dividing themselves very quick. They also adapt to the surrouding environment around them (inside our body) very quickly. There are four types of virus cycles, and they are lytic cycle, lysogenic cycle, retrovirus and envelop virus. In lytic cycle is the process that the virus move around and find the bacteria that are beneficial to our body and it injects its DNA into the the host. The DNA inside the host began to break down and eventually break into viruses, after it becomes too much for the cell to store, the cell eventually burst and release the viruses. Examples of lytic cycle is E-Coli. During the lysogenic cycle, the virus DNA become part of the bacteria DNA and it becomes a pro-virus and is inactive for period of times. The cell eventually divide into daugther cells, and the virus become the lytic cycle. Example of lysogenic cycle is Herpes. Retrovirus is a type of virus that is constantly changing, and it usually makes random mistakes. It enters the nucleus and become part of the DNA and through DNA replication, the virus cell become RNA and enter the ribosome and create the harmful protein and the virus spread and divide exponentially. Example of retrovirus is the HIV virus that cause the deadly disease, AID. During the envelop virus, instead of entering the nucleus and become part of the DNA, it went through the ribosome, and example of that is Hepatitis C.

Pech's Blog entry #12

During the past few weeks, we've been studying DNA replication, and RNA. DNA replication always happen during the interphase period because during the interphase, it is usually the resting time and the longest phase compare to the other cell cycles. DNA can not transfer itself to the ribosome to create protein, it goes through DNA replication and by using the polymerase to make new bases and RNA primase, it create a new RNA strand. The RNA strand carries the datas from DNA to the ribosomes and after the RNA enter the ribosomes, new proteins are created.
We've also talked about mutation. Mutation is the change in DNA sequence and there are three different type of mutation. They are substitution, insertion and deletion. During the substitution process it replaces one nucleotide with another, it also can be known as the silent mutation because there is no changes in the protein. During the insertion process is when the mutation add another nucleotides into the sequence causing the protein to change. Deletion is when mutations remove nucleotides from the sequence.