Micro: Immune System and Immunodeficiency Virus Infection Essay

Submitted By kburley1913
Words: 4619
Pages: 19

Can viruses be seen with a light microscope? no- viruses can only be seen with an electron microscope.
Can the genome of a virus contain both RNA and DNA? no- they only contain one or the other.
Whats a genome? entirety of an organism's hereditary information.
True or false: Virus genome might have enzymes packaged with it.
How do viruses replicate in human cells?
DNA virus: viral DNA copied in the nucleus..
RNA virus: replicated in the cytoplasm
Do viruses undergo mitosis? no- they are dependent upon host enzymes to produce new virions.
What makes a virus host specific? the chemical attraction and exact fit between proteins and glycoproteins on the virion and complementary protein and glycoprotein receptors on the cell membrane.
Name the five general stages of the replication cycle in viruses:
1.attachment: attachment of the virion to the host;
2.entry: the entry of the virion or it's genome into the host;
3.synthesis: synthesis of new nucleic acids and viral proteins by the host cells enzymes and ribosomes;
4. assembly: assembly of the new virions inside the host cell;
5. release: release of the new virions from the host by exocytosis/budding.
How do these stages differ in bacteriophages vs animal viruses? bacteriophage- lysis - bacterial cell is destroyed through release of virus. lysogenic=prophage; animal virus- latent=provirus.
Also, when the bacteriophage enters a bacterium, only the DNA/RNA is released into the cell (capsid remains outside). However, when viruses enter animal cells, the capsid goes into the cell creating the extra step of uncoating.
What's the difference between virion and viroid?
A virion is a virus outside of a cell consisting of a proteinaceous capsid surrounding a nucleic acid core. A viroid is an extremely small circular piece of RNA that is infectious and pathogenic in plants.
What's the difference between a naked virus, nucleocapsid and prion?
A naked virus is a virion without a membrane (envelope). A nucleocapsid is a nucleic acid and it's capsid. A prion is a proteinaceous infectious particle that lacks nucleic acids and replicates by converting similar normal protein into a new prion.
What is the advantage of a virus having an envelope? Disadvantage?
Advantage: protection from immune system.
Disadvantage: easily damaged (AIDS virus), does not survive well on objects.
What's the difference between a capsomere and a capsid?
A capsid is a protein coat and determines the virus' shape. The capsid is typically made up of many identical protein units. Each individual protein unit is called a capsomere.
Name three viruses that cause congenital defects:
Herpes, Rubella, Cytomegalyvirus
What word is used to describe these viruses: teratogenic What is a bacteriophage? Why is it significant?
A bacteriophage is a virus that infects and usually destroys bacterial cells. It is significant because it can potentially be used as an alternative to antibiotics. They are excellent tools for the general study of viruses because they are easier and less expensive than animal or human viruses to culture.
What is generalized transduction? the transducing phage carries a random DNA segment from the donor host cell's chromosome or plasmids to a recipient host cell. (usually lytic stage)
What is specialized transduction? only certain host sequences are transferred along with phage DNA. (usually lysogenic stage first)
Name two viruses that cause cancer:
Papilloma and Epstein Barr virus
What word is used to describe these viruses: oncogenic How is a virus similar to chlamydia? How is it different? both are OIP's. Chlamydia is a bacterium, but in some ways it's one that acts more like a virus. It is virus-like, because it is dependent on molecules from its host organism to reproduce. In contrast to viruses, they have both DNA and RNA, cytoplasmic membranes, functioning ribosomes, reproduction by binary fission, and metabolic pathways.
Name some shapes seen