Ch13 Viruses Flashcards
(20 cards)
Why are viruses said to be obligate intracellular parasites
Because they cannot reproduce without a host cell
Classified viruses on there morphological types
Helical nucleic acid found inside
Polyhedral many sides capsid uses host finding device
Complex several complicated structures infects bacteria
Taxonomy give an example of a family genus and species for a virus
Family name ends in viridae
Genus name ends in virus
Viral species common names are used for groups of viruses sharing same genetic info
What are the structural components of a virus define capsid and capsomere in there what is virion
Structure is nucleic acid genome and a protein caps and that covers the genome
Capsid is an outer covering of protein that protects the caps for mayor is a subunit of a capsid
Some viruses have an envelope what is the chemical make up of the structure and how is it acquired
Envelope is made from portion of host cell membrane which is phospholipids and proteins and has obtained through budding cell does not burst lysogenic cycle
What are the types of spikes found on some viruses
A peplomer Glycoprotein spike on a viral capsid or envelope these protrusions will only bind to certain receptors on a host cell
What is meant by the host range specificity of a virus
Viruses can only affect certain species of host and only certain cells within that host
Viral identification list three techniques used to identify viruses
cytopathic effects visible and sell that are caused by viral infections will cause changes in cell
Serological test Reaction effect with antibodies
Nucleic acid’s see patterns tell what virus
What are the methods used to culture viruses in the lab
Viruses must be grown in living cells need to host but not nutrients provide sell and TSA grown an egg or you cell culture
What group of viruses have an enzyme called reverse transcriptase days what is the function of this enzyme
Retroviruses and then function has RNA genome that converts are now back to DNA before hijacking cell
Define persistent viral infection and provide examples
HPV, hep b, the measles
Disease process that occurs over a long period generally fatal
What is bacteriophage name and explain the five stages bacteriophage infection lytic cycle
Stage one attachment by tail fibers to host stage to penetration tell inserts DNA into cell with nucleic acid’s stage III biosynthesis production of DNA/protein for mature ration assembly of pairs five release cell BUrsts and All viral parts are released
What type of growth curve is demonstrated by viral multiplication how does each part of the curve relate to the stage of the lytic cycle
Attachment one virus
penetration 0 to 1 virus
biosynthesis/maturation zero viruses
release 0 to 100 viruses
What is the difference between lytic and lysogenic viruses
Lytic Reproduction of viruses using Host then burst out of cell killing cell
Lysogenic incorporates host DNA cell does not die
What is prophage
When a virus attached to host dna
Describe specialized transduction
Involves the transfer a few specific genes from one bacterial cell to another by means of phage
What are the stages of animal virus replication
Attachment penetration through endocytosis uncoating biosynthesis maturation
How does animal virus replication differ from bacterial phage replication
Animal viruses endocytosis and uncoating for bacterial phage does not
Define oncoGene and transformed sell
Oncogene Gene that causes cancer
Transforms a transformation in genetic alteration increased growth and used as a tumor marker from T antigens
Some viral infections are said to be latent infections what does this mean and provide examples of Layton viral infections what group of viruses are most important and causing latent infections
Layton viral infections are virus remains in a symptomatic Cells for long periods example herpes viridae cold sores shingles and is activated by stimulus of heat or truck
