Ch. 19 Viruses
Bacteria Viruses
Animal Viruses
HIV viruses
Emerging Viruses and Prions
Lytic Cycle
Lysogenic Cycle
Attachment
Entry of phage DNA and degration of host DNA
Synthesis of viral genomes and proteins
Self-assembly
Release
Viruses attach to host cell
Injects DNA/ genetic material
Replication of phage protein and genome
Three sets of proteins form phage heads, tails, and tail fibers.
The cell burst, releasing 100 to 200 phage particles
Phage DNA integrates
Prophage is copied
Cell division
Daughter cell
Inject genetic material
Into bacterial chromosomes which becomes into prophage
Bacterium reproduces normally
Transmitting it to daughter cells
Produce bacteria infected with the prophage
Are formed with the prophage
General Viral Replicative Cycle
The virus enters the cell and is uncoated
Releasing viral DNA and capsid proteins
Host enzymes transcribe the viral mRNA
Host enzyme replicate the viral genome
Viral genomes and capsid proteins self-assemble into new virus particles, which exit the cell
Which host ribosomes use to make more capsid proteins
The viral genome functions as a template for synthesis of complementary RNA strands by viral RNA polymerase
Copies of viral genome RNA are made
Capsid and viral genome enter the cell
Complementary RNA strands also function as mRNA
Vesicles transport envelope glycoproteins to the plasma membrane
Viral envelope binds
A capsid assembles around each viral genome molecule
New virus buds from the cell
injects genetic material
Digestion of the capsid by cellular enzymes releases the viral genome
Using the complementary RNA strands as templates
Which is translated into both capsid protein and glycoproteins for the viral envelope
its envelope studded with viral glycoproteins embedded in membrane derived from the host cell
The double stranded DNA is incorporated as a provirus into cell's DNA
Proviral genes are transcribed into RNA molecules
Reverse transcript catalyzes the synthesis of a second DNA strand complementary to the first
The viral proteins include capsid proteins and reverse transcriptase and envelope glycoproteins
The virus fuses with the cell's plasma membrane
Reverse transcriptase catalyzes the synthesis of DNA strand complementary to viral RNA
The envelope glycoproteins enable the virus to bind to specific receptors on ceratin white blood cells
Vesicles transport the glycoproteins to the cell's plasma membrane
The capsid proteins are removed
releasing the viral proteins and RNA
Which serve as genomes for progeny viruses and as mRNAs fr translation into viral protein
Capsids are assembled around viral genomes and reverse transcriptase molecules
New viruses, with viral envelope glycoproteins, bud from the host cell
Epidemic
Pandemic
global
Country/ continent
NOT viruses or cells
attach to normal proteins
Hemoglobin
Antibodies
Cell membrane
Hormones
Enzymes