Viruses Flashcards
What is a virus made up of
Genetic material (rna OR Dna)
Proteins
Structure of a virus?
Core or nucleic acid surrounded by protein coat (capsid)
Define cell parasite
- depend on living cells for existence
- while harming the organism
Is a virus a cell? If so, why? If not why not?
NOT A CELL
- smaller than a cell
- no cytoplasm or orangelles
What did virus originate from?
Genetic material of disrupted cells
-theory
Non living characteristics of a virus
- non cellular
- do not reproduce
- contains dna or rna
- depends on host cell
Living characteristics of a virus
- Have genetic material
- Do evolve
- have structures related to function
- Replicate (Not reproduction)
- There are diverse species of viruses
What is a virus
Non-cellular particle
Three main shapes of a virus
- rod
- spherical
- tadpole
define bacteriophage
- A virus that invades bacteria
- Have a more complex structure than normal viruses
Define viral specifity
-Viral infections are specific to a species or group or cell type
ie- plant viruses can only attack plant cells
- Viral genome must match enough host DNA to overtake metabolic function of cell
What are the 5 steps to using viruses as a vector for gene therapy?
- Cells are removed from patient
- A virus is deactivated/altered so that it will not effect the patient.
- A gene is then injected into the virus
- Altered virus is mixed with the removed cells from patient
- The cells and gene-injected virus are then injected back into the patient, and the cells in the patient start to replicate the good genes,and they become genetically altered.
How are viruses spread?
-directly by fluid contact
ie- Kissing
-Indirect by air, water, and food
ie- eating a carrot someone sneezed on :(
What does virulence mean?
-How infectious, damaging, and disease causing a virus is
What are the four non-specific defense systems towards viruses?
1. Barrier (1st line of defense) ie-skin 2. Phagocytes (second line) ie-white blood cells engulfing the virus 3. Fever (second line) ie-to denature the protein in the virus 4. Interferon (second line) ie- a special protein that interferes with replication
What are the two specific defense systems towards viruses?
- Antibodies (3rd line)
2. Immunity (3rd line)
What are antibodies
- Biological molecules made in responce to SPECIFIC ANTIGENS
- They attach to antigens (specific like lock and key), which are located on the surface of the virus
- they create memory cells
What is immunity?
-After exposure to a pathogen (Anything foreign in the body), memory cells remain in your immune system. The memory cells produce antibodies very quickly; before a disease can develope
What are vaccinations?
- Weakened or synthetic forms of pathogens
- Injected into organisms to produce antibodies, and memory cells in body
- The “synthetic” infection is met with body’s second immune response.
Active immunity?
-Occurs when YOUR OWN body processes antibodies in response to pathogen or vaccine
Passive Immunity?
- Occurs when antibodies produces by other animals are injected
- Trigger immune response
- Travelers are sometimes given antibodies against tropical diseases before they leave home
Indicate several non-living characteristics of viruses
Contains rna or dna
Do not reproduce
Non cellular
Depend on host cell
