first review questions

first review questions - Four classes of eukaryotic cells...

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Four classes of eukaryotic cells include plant, animal, fungi, and protist Eukaryotic cells typically have a phospholipid bikayer, discrete organelles, cytoskeleton, and a nucleus and nucleolus. Prokaryotes do not have distinct organelles, are lacking in a membrane to house DNA, do not have proteins involved in packing the DNA, and have a different machinery for flagella and cilia. Bacterial cell walls specifically contain peptidoglycan. The replication cycle of HIV starts when the gp120 envelope proteins allow the virus to be taken into the host cell by receptor mediated endocytosis. The packaged enzyme RNA transcriptase allows the two copies of viral RNA to be transcribed into DNA strands and their compliments, and integrase allows this DNA to be hidden in the host DNA. Nuclear Localization sequence allows passage into the nucleosome pore complex, and the integration signal sequence is the area in the seuqence that the integrase uses to attach to the viral DNA, circularize it, and move it. This lysogenic portion of the cycle allows for the dormant viral DNA to be used by the hosts’ transcription and translation machinery to make viral product. The three main genes, GAG POL and ENV, making the viral packaging protein, polymerase, and envelope protein, proliferate in the cell, and are made in the ratios of 4:4:2, a proportion maintained by the order of appearance in the 5’-3’ direction. As more ribosomes fall off toward the end, they are less likely to make it to the ENV segment. Specifically, envelope proteins are packaged by the golgi body and transported to the cell membrane. When the virus is triggered into lytic phase, these parts assemble into a new generation of viruses, which are transported to the membrane, wrapped by the envelope protein waiting, and lyse the cell. Adenoviruses are doubles stranded DNA, HIV is single stranded RNA virus, and bacteriophage can have any arrangement but are typically smaller in base pair length. Since HIV is a single stranded RNA virus, it must have RNA transcriptase to encode its genome to DNA for insertion into genome. Adenovirus has single strand DNA, making it more stable and not requiring reverse transcriptase. The typical host of HIV is the macrophage, bacteriophage bacteria, and Adenoviruses attack somatic cells including intestinal,
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first review questions - Four classes of eukaryotic cells...

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