TEST 2: Viruses Flashcards
General characteristics of a virus
- 10 to 100x smaller than bacteria
- Infects a specific type of host cell
- Composed of genetic material, surrounded by protein coat.
- Lack all organelles, including ribosomes
- Lacking all molecules needed to make a protein.
- Lacking all molecules needed to copy their genetic material.
- UNABLE TO PRODUCE ON THEIR OWN AND ARE NOT CONSIDERED CELLS
How does a virus reproduce?
- Attaches to host cell
- Enters host cell and releases genetic material.
- Host cells machinery is used to make copies of viral, genetic material and to build viral proteins.
- New viruses are assembled and leave host cell while host cell continues to produce new viruses
How does virus differ from bacteria?
Bacteria: organelles, can metabolize grow and reproduce on their own, often harmless, can be treated with antibiotics, larger
Virus: no organelles, cannot metabolize grow and reproduce on their own, often pathogenic, does not respond to antibiotics, smaller
Why are antibiotics effective to treat viruses?
They target bacterial processes that viruses don’t have
Not only would it be ineffective, it would contribute to the rise of antibiotic resistant bacteria
How does your immune system respond to a viral infection?
Adaptive immune responses and memory responses
Adaptive immune response example
T helper cells: activate, B cells, and cytotoxic T cells
Cytotoxic T cells: kills virus infected cells
B cells: produce antibodies to neutralize virus
Memory response examples:
Memory B and T cells: remember the virus for faster future responses
Define antibodies
Proteins produced by B cells of the immune system in response to bacteria and viruses
Each is specific to a particular antigen
Roles of antibodies (3)
- Can bind to viruses to neutralize toxin.
- Can flag for immune cells.
- Can prevent viral spread.
How do vaccines work?
-stimulate the immune system by introducing inactivated pathogen
- train the immune system to recognize and remember the pathogen without causing disease
-if body encounters later, immune system can quickly respond
Why do vaccines work?
Memory response antibodies
Define inject viral surface proteins
Vaccine strategy that uses viral surface proteins to trigger an immune response
The body will then produce antibodies and memory cells to fight the actual virus later
Define inject empty virus particles
Of vaccine practice that uses empty viral shells with no genetic material to stimulate immunity
The immune system recognizes the viral surface proteins and prepares to fight the virus
Define mRNA vaccines
Vaccine strategy that delivers mRNA to cells instructing them to produce viral proteins
The immune system, then response to the proteins, creating memory cells to protect against future infections
