Viruses Flashcards
Why can viruses not be placed into any of the 5 kingdoms of living organisms?
Viruses display characteristics of living organisms(such as reproduction) and characteristics of non-living organisms(they cannot Respiror,excrete ect.)
Viruses are best described as infectious particles
Define virology
Virology is the study of viruses
What are parasites and what do they do ?
an organism that lives in or on an organism of another species (its host) and benefits by deriving nutrients at the other’s expense.
Lives on living material and causes harm to it
How do viruses reproduce?
Viruses can only reproduce once the virus is inside cells of living organism/host cell (OBLIGATE ENDOPARASITES)
Viruses reproduce by changing the genetic material(of the host) to its own
What do we mean by viruses are host specific?
They usually only attack a certain type of tissue
What do we mean by viruses are acellular?
It doesn’t have a cell I.e nucleus, cytoplasm, organelle
Are viruses Eukaryotes or Prokaryotes?
NONE
They are not classified as either
Can antibiotics be used against viruses?
No, antibiotics are ineffective against viruses since they are non-living
What I’d the basic structure of a virus?
Viruses have a simple structure. They consist of a central nucleic acid, either DNA or RNA but not both. The nucleic acid is surrounded by a protein coat.
The protein coat surrounding the nucleic acid is called?
The caspid
In some viruses the caspid is covered in an envelope of a lipid bi-layer
What are Eukaryotes?
Organisms that posses a true nucleus
A TRUE NUCLEUS is a nucleus surrounded by a nucleur membrane. The organelles in Eukaryotes are all bound by membranes
What are Prokaryotes?
Organisms with nuclear material that is not enclosed by membranes. The organelles found in Prokaryotes do not have a membrane
Viruses that infect plant cells contain DNA or RNA ?
RNA
Viruses that infect animals contain DNA or RNA?
DNA/RNA
Viruses the infect bacterial cell contain DNA or RNA? And what are they called
Bacteriophages contain DNA
How do viruses spread?
Through the atmosphere, in water and by vectors
What does HIV stand for
Human Immuno-deficiency virus
What does AIDS stand for ?
Acquired Immuno Deficiency Syndrome
How does HIV enter the blood?
Via open wounds/body fluids
What does HIV do to white blood cells?
The virus attacks WBC(T4 lymphocytes) making them incapable of producing antibodies
Destroy WBC - destroyed immune system and thus person becomes highly suseptible to contracting other diseases
What are antibodies?
a blood protein produced in response to and counteracting a specific antigen. Antibodies combine chemically with substances which the body recognizes as alien, such as bacteria, viruses, and foreign substances in the blood.
Antibodies fight against other disease causing organisms that enter the body
When does a person have AIDS ?
When an HIV positive person has an additional disease, such as TB, we say the person is suffering from AIDS
Aids symptoms?
- weight loss
- sweating
- TB
- phenomenon
- diarrhoea
How is HIV transmitted?
- blood transfusion
- sextual intercourse
- sharing hypodermic needles
- mother to child, either through placenta or breast milk
How to avoid getting AIDS?
- don’t share hypodermic needles
- avoid contracting STDS
- when attending to a person who is bleeding, wear protective clothing and gloves to avoid infection
Is there a cure for HIV/AIDS
No
What are the 2 treatments for HIV
PEP- post exposure prophylaxis
ART Treatment- anti-retroviral therapy
What is PEP treatment?
Available to health care professionals and people who may have been exposed to the HIvirus(accident/rape)
Treatment must start within 24hrs of exposure and must be adhered for 28days
What is ART treatment?
Medication is given to people who have been HIV+ for a while. The drugs inhibit the life cycle of the virus causing it to not reproduce rapidly. Patients on the ART treatment will live a long, healthy life as long as their Medication is taken strictly as prescribed for the rest of their lives
What are vaccines?
Attenuated viruses(weakened forms of the virus) stimulate the immune system to make antibodies that fight off the viral infection
