Lecture 14 Flashcards
Can viruses reproduce?
Yes and No - they can not reproduce unless inside a cell
Can viruses utilize energy?
No.
Can viruses carry out chemical reaction?
No.
Can viruses engage in mechanical activities?
No
Can viruses respond to stimuli?
No
Are viruses capable of self-regulation?
No
Can viruses evolve?
Yes
Are viruses cells?
No
What are viruses?
Macromolecular packages that can function and reproduce only within living cells
What are viruses outside of cells?
Inanimate particles called virion
What is a virion made of?
Small amount of DNA or RNA that encodes a few hundred of genes
A protein capsule called capsid
What is the size of a virus?
Roughly 1000 nanometer
What is one of the first viruses to be characterized?
TMV was one of the first viruses to be characterized
What is the Baltimore Classification?
Categorizes viruses based on the type of genome (RNA/DNA) and their method of replication.
What is HIV an example of?
A retrovirus (A RNA virus that can insert a copy of its genome into the DNA of a host cell to cause AIDS)
What is Hepatitis B a member of?
The hepadnavirus family (DNA type), which affects human liver and causes serious infections.
What is Ebola virus apart of?
The filoviruses family- encodes their genome in the form of single stranded negative - sense RNA.
What are Adenoviruses?
A group of viruses that can cause respiratory illnesses (bronchitis, pneumonia) or conjunctivitis (an infection of the eye)
What is a Bacteriophage?
A virus that infects and replicates within archaea and bacteria
How many virus species have been formally described?
4,985
What have bacteria evolved as a way to battle the continuous attacks from bacteriophages?
An immune like system called the CRISPR-Cas
What is a narrow host range?
Human cold and influenza viruses that infect epithelial cells of human respiratory system (most common type)
What is a wide host range?
rabies, that can infect cells in dogs, humans, bats and raccoons
What happens once a virus is inside a cell?
It hijacks cellular machinery to synthesize nucleic acids (DNA/RNA) and proteins.
What are the two main types of viral infection?
Lytic and Non-Lytic
What is a lytic virus?
Production of virus particles ruptures (and kills) cell (e.g, influenza, rabies)
What is a non-lytic virus (lysogenic)?
Viral DNA is inserted in host genome, the infected cell can survive, often with impaired function (HIV, Chicken Pox)
Papovavirus
A large family of viruses that includes the human papilloma virus (HPV)
What does the rabies virus have?
An enveloped single stranded RNA genome
What does the RNA genome encode of the rabies virus?
Five genes: nucleoprotein (N), phospoprotein (P), Matrix protein (M), glycoprotein (G) and viral RNA polymerase (L)
How many genotypes of rabies virus are known?
7 genotypes
What does Zika virus cause?
A large number of infants born with microcephaly
How is Zika Virus transmitted?
Primarily by mosquitoes, but also through sexual contact or blood transfusion
What is microcephaly?
A condition where the head circumference is smaller than normal
Affects early brain development causing delayed motor and speech functions, intellectual disability, seizures, hyperactivity, etc.
How does Zika Virus get transmitted?
It crosses the placental barrier by targeting trophoblasts and macrophages
If infection of the fetus occurs during the period of neurogenesis, the survival of neural progenitor cells (NPCs) can be affected
How do RNA vaccines work?
They trick the body’s cells into producing a fragment of a virus, an antigen, from an RNA template.
What is a strategy to make RNA vaccines more effective at lower doses?
Incorporate the instructions for assembling a replicase, which can make lots of copies of the RNA template for producing antigens.
