Viruses Flashcards
(NJCTL) A virus is a small … agent that can replicate only inside the … of organisms, though they are not organisms themselves
infectious; living cells
(NJCTL) Viruses are particles that are not considered living because they cannot perform all the functions of living things (e.g., …)
However, they share the same … and use the mechanism of host cells to …
metabolism; genetic code; reproduce
(NJCTL) T-even viruses have a … containing …, a …, …, a …/…, and … which are necessary for …
head; DNA; collar; sheath; base plate/end plate; tail fibers; attachment
(NJCTL) In biology viruses are important because their genetic and reproductive strategies use the same … but their use is unique. Scientists have learned a lot about genetics by understanding their strategies. In addition, their infectious nature makes them a threat that requires humans to understand how they work to create defensive technology.
molecular components
(NJCTL) H-spike allows flu/viruses to …
N-spike allows it to …
bubbles are … .
gain access; exit; virus particles budding
(NJCTL) immunity: have … that bind to … of viruses and .. them for destruction by way of …
antibodies; surface proteins; tag; macrophages
(NJCTL) The general mode of operation for all viruses is to:
infect a host cell with its …
hijack the molecular machinery of the host cell to … needed to ….
package the parts together to form new … for … from host cell
genetic information; manufacture the parts; build more viruses; viruses; release
(NJCTL) Viruses are …. parasites, which means they can reproduce only within a … Each virus has a …; it is limited by type of … that it can infect (due to similarities in … (?))
obligate intracellular; host cell; host range; host cells; glycoproteins
(NJCTL) Viruses use …, …, and other parts of the host cell to synthesize new viruses
enzymes; ribosomes
(NJCTL) zoonosis: virus can jump from … to …
this does not equate to …
species; species; pathogenicity
(NJCTL) viruses consist of 2 main macromolecules: … and ….
proteins; nucleic acids
(NJCTL) flus come from
birds
(NJCTL) the lytic cycle is a viral reproduction that causes the … of the host cell. It produces new … and digests the host’s … thereby releasing new viruses.
death; phages; cell wall
(NJCTL) Unlike the lytic cycle which is detrimental to the host cell, the … cell does not cause the cell to die
lysogenic
(NJCTL) In the lysogenic cycle, the virus’s DNA is … into the host’s … Then the bacteria cell continues to … through …, copying the … and its own together
incorporated; DNA; replicate; binary fission; viral DNA
(NJCTL) many viruses are only able to utilize the lytic cycle. Some viruses, called …, can utilize both the lytic and lysogenic cycles
temperate phages
(NJCTL) When a temperate phage switches from the lysogenic cycle to the lytic cycle, it separates its … from the …. and then proceeds through the steps of the … as usual
phage DNA; host DNA; lytic cycle
(NJCTL) temperate phages
however, sometimes when the virus DNA separates it takes with it some of the … –> …
bacteria’s DNA; transduction
(NJCTL) Viruses do not contain
ribosomes
(NJCTL) The lysogenic cycle increases … in a population of cells
genetic variation
(NJCTL) … phages are DNA viruses
T even
(NJCTL) some viruses use DNA as their genetic material. It does not contain …, so in order for it to reproduce it must inject its DNA into a cell so that it an be … by the host cell’s …
DNA polymerase; copied; polymerase
(NJCTL) An RNA virus is a virus that has … as its genetic material. This nucleic acid is usually … (ssRNA), but may be … (dsRNA). Some human diseases caused by RNA viruses include …, …, …, …, … and …, …
RNA; single-stranded; double-stranded; SARS; influenza; hep C; West Nile fever; polio; measles; smallpox
(NJCTL) Severe acute respiratory syndrome (SARS) is a vital … disease in humans. They are enveloped … that are pathogens of … and … This group of viruses causes … infections in a variety of animals, including humans
respiratory; RNA viruses; mammals; birds; respiratory tract
(NJCTL) A retrovirus is an RNA virus that replicates in a host cell, like … First it uses its own … enzyme to produce … from its …, reverse of the usual pattern, thus retro.
HIV; reverse transcriptase; DNA; RNA
(NJCTL) Retrovirus:
This new DNA is then incorporated into the host’s … by an … enzyme. The cell then treats the viral DNA as part of its own instructions, which it follows blindly, making the … required to assemble new copies of the virus.
Retro viruses have enzymes that allow access into …
HIV only access … cells
genome; integrase; proteins; nuclear envelope; T-helper
(NJCTL) Retro viruses are some of the most complex and believed to be the most advanced from an evolutionary perspective. For a virus, their entry system into cells is highly complex. They have systems to bypass the usual … of their host cell.
defenses
(NJCTL) CD4 receptor that HIV binds to is found only on … cells. For HIV, some RNA leaves the cell, others are used for … into enzymes like reverse transcriptase
T-helper; translation
(NJCTL) HIV is particularly dangerous because it attacks the immune system and fools it into treating it is as part of the system. No immune attack is offered by the infected cells. The complex replication system is flawed and many errors are made as the virus replicates its genome, indicating that many … occur. This makes it difficult to treat because the virus does not stay the … More than 1 form per patient. Attacking the virus would also attack …
mutations; same; immune system
(NJCTL) What part of the virus enters the bacterial cytoplasm
the nucleic acid
(NJCTL) The rapid mutation rate of RNA viruses as compared to DNA viruses is due to the fact that DNA is more … than RNA
structurally stable
(NJCTL) … are a class of enzymes used by bacteria as weapons against invading phages. They look for specific … in pieces of DNA and … them, thereby destroying the foreign DNA entering the cell
Restriction enzymes; sequences; cut
(NJCTL) animals have two categories of defense against invaders: … and …
innate immunity; acquired immunity
(NJCTL) innate immune defenses are .. systems, preventing invasion by all …
Acquired immune defenses are developed during the animal’s lifetime and respond only to …, those that have been encountered previously. This is only in vertebrates
generalized; pathogens; specific invaders;
immunity for bacteria comes by way of …, which … viral DNA
restriction enzymes; cut
lytic cycle … cell wall, and consists of 5 stages: …, …, …, …, and …
ruptures; attachment; penetration; biosynthesis; maturation; release
(lytic cycle) attachment: … combines with … on the bacterial cell wall
capsid; receptor
(lytic cycle) penetration: viral DNA enters the host after an … … part of the …
enzyme; digests; cell wall
(lytic cycle) biosynthesis: … are synthesized and the virus inactivates … that aren’t necessary to ….
viral components; host genes; viral replication
(lytic cycle) maturation: viral … and …. are assembled to produce … and … –> an enzyme that …. the …
DNA; capsids; viral products; lysozyme; lyses; cell wall
(lytic cycle) release: new viruses … the host cell, bacterial cell …
leave; dies
(lysogenic cycle) the virus incorporates its DNA into that of the bacteria
after attachment and penetration, viral DNA is integrated into the bacterial DNA without … the host DNA –> …
damaging; integration
(lysogenic cycle) when dormant, the viral DNA is a … which is … with the host DNA, and the subsequent cells, which have the …, are called … cells
prophage; replicated; prophage; lysogenic
(lysogenic cycle) environmental factors then stimulate the commencement of the …, and … continues as it would in the lytic cycle
biosynthesis; reproduction
(animal virus) if an animal virus has a viral envelope, it will … to … on the cell membrane by way of …
bind; receptors; glycoproteins
(animal virus) the viral genome penetrates the cell, covered by the … and … and these are removed once the virus is inside
capsid; envelope
(animal virus) biosynthesis then occurs and assembled viral particles are released via …, in which the virus picks up its …, which consists of …, …, and … from the host cell, primarily from the cell’s … –> similar to … Cell becomes “virus factory”
budding; envelope; lipids; proteins; carbs; plasma membrane; exocytosis
(animal virus) differences between bacterial and animal viruses
site of attachment:
bacterial is … proteins, animal is … proteins and …
penetration: bacterial- … enters, animal- … enters via endocytosis
biosynthesis can occur in the … along with the … for animal viruses, where it only occurs in the … for bacteriophages
cell wall; plasma membrane; glycoproteins; viral DNA; capsid; nucleus; cytoplasm; cytoplasm;
differences between animal and bacterial viruses cont:
release incorporates …, not … for animal viruses
for animal viruses, most incorporate themselves into …
budding; lysing; host DNA
differences between animal and bacterial viruses cont:
bacterial viruses are mostly … and … viruses, in animals there are …, …, …, …, …, …, viruses
BASICALLY, greater types of viruses in animals, of entirely different natures –> more …
DNA; RNA; single-stranded DNA, double-stranded DNA, single-stranded mRNA, double-stranded mRNA, positive mRNA, negative RNA; complexity
retroviruses infect the already …
differentiated white blood cells
white blood cells/red blood cells don’t …, they are produced by …
…
divide; bone marrow; differentiation
viral envelopes cover … (virus’s …) and helps the virus avoid the …
capsids; protein shell; immune system
our defense against viruses: … system, … cells
immune; natural killer
(Antivirals) sweet gum helps create … (prime ingredient - …) which is medicine people use for …, has an … property
tamiflu; shikimic acid; influenza; antiviral
(Antivirals) antivirals don’t actually “kill” viruses –> they … of the illness
shorten duration
(Antivirals) antivirals operate on either … or …
H; N spikes
(Antivirals) Shikimic acid works on the … and prevents the virus from ..
N spike; budding
(Antivirals) viruses are prevented by taking
vaccines
(Antivirals) Sepsis: related to toxic shock syndrome, when an infection goes into
tissues
(vaccines) massively fatal discontinuities of life: … million people would die
severe … most probable of all of these disasters
100; flu pandemic
(vaccines) power of vaccines like a whisper: … cells in lymphatic system- cultivated such that they become .. cells
B memory; plasma
(vaccines) … and … are viruses that were effectively eradicated by using vaccines
smallpox; polio
(vaccines) humans don’t have natural immunity for
HIV
(vaccines) HIV affects … cells and …, as well as … cells.
dendritic; macrophages; T helper
(vaccines) Memory B cells turn into plasma cells that produce … that prevent … Vaccines speed up rate at which … turn into … and thus enhance our own immune functions
antibodies; infection; memory B cells; plasma cells
(vaccines) when flu and HIV mutate, they change shape such that the antibodies can’t
recognize them anymore
(vaccines) Broadly neutralizing antibodies: … and … many forms of the infection
new surface structures found that changes very little as virus … –> this is what the broadly neutralizing antibiotics latch onto
latches on; disables;; mutates
(vaccines) … spots also don’t change much when virus mutates, and antibodies could latch onto it and destroy it
M2e
(vaccines) Smaller vaccine such that it can be made by way of … which reproduce .., rather than using …
bacteria; quickly; chicken eggs
(vaccines) working backwards from antibody to vaccine:
retro vaccinology
