Viruses and Bacteria (11)
No description yet. This curated deck is ready for daily study.
Card preview (24)
What is biodiversity?
The great variety of organisms (plants, animals and micro-organisms) found on earth.
What is a procaryote?
Organisms which do not have a true nucleus or cell.
What is a eukarote?
Organisms which have a true nucleus and cell.
Characteristics of viruses:
-non living -obligate intracellular parasites -Force a living cell to make copies of the virus -Always pathogenic -Can remain within an organism in a dormant state. -Have different shapes.
Virus shapes:
Polyhedral ( cubical) Helical (spiral) Complex (tadpole-like)
Structure of viruses:
-Acellular ( no nucleus, cytoplasm, organelles) -Contains DNA or RNA -Nucleic acid is surrounded by a protein coat or capsid
Draw complex (bacteriophage) and generalised virus:
In book
What are the four phases of the HIV life cycle?
Absorption, penetration, latent and lysis.
• Adsorption
HIV locator spikes attach to receptors proteins on membrane on CD4 cell.
• Penetration
Virus penetrates cell, shedding its protein coat.
• Penetration
Virus releases RNA, along with an enzyme, reverse transcriptase.
• Latent
Reverse transcriptase uses the viral RNA strand as a template to form a double strand of viral DNA.
• Latent
Viral DNA enters cell nucleus, hijacking cells DNA, making it produce more viral RNA.
• Latent
The cell loses its function, becoming a virus factory.
• Lysis
The new HIV’s erupt from cell causing CD4 cell death, and going on to infect many more CD4 cells, crippling the victims immune system.
What does HIV stand for?
Human Immunodeficiency virus
What does AIDS stand for?
Acquired Immune Deficiency Syndrome.
What does HIV do?
Destroys immune system cells (helper T-lymphocytes/CD4 cells). The immune system is the bodies defence against infection, destruction of CD4 cells leads to the immune system becoming very weak.
What is the number that shows the progression from HIV to AIDS?
less than 200 CD4 cells/ ml blood.
What kind of virus is HIV and how is it transmitted?
A retrovirus, transmitted through any bodily fluid.
Management of HIV:
Find out HIV status- to take measures to manage and prevent spreading. Treat with antivirals (ARV) with CD4 200-500 Opportunistic infections are treated. Immune system must be strengthen. Avoid alcohol and drugs. Take care of emotional health.
Bacteria charceteristics:
-Kingdom Monera, first organisms to evolve. -Most abundant and diverse organisms on earth. -Inhabit practically all environments. -Most are useful, some are pathogenic. -Unicellular -Some use chemicals or sunlight to make food but others are parasites. -Vary in shape
What are the bacteria shapes?
-Cocci (spherical) -Bacilli (rod-shaped) -Spiralla (spiral) -Vibrio (comma)
How do bacteria produce?
Asexually by binary fission.