bacteria and pathogens Flashcards
(19 cards)
What are antibodies?
proteins created by leukocytes that bind to pathogens, inhibti their functioning which makes them more susceptible to be consumed by macrophage white blood cells.
how do retroviruses vork and how do they contribute to evolution?
retroviruses inject their rna into the host cell which is then written into the genome via the injected enzyme reverse transcriptase. this is then copied into the daughter cells during the s phase of mitosis
- when the virus is copied, the host cell reads the DNA, causing the portein/ virus to multiply and cause lysis.
- they contribute to evolution because some host cells have a epigenetic tag or a methyl group that prevents the copying of the viral DNA, which gives them an evolutionary advantage.
what are pathogens?
any microorganism that causes disease?
-inckuding fungi, parasites, viruses and bacteria
what makes archaea and eubacteria different from each other? what do they have in common?
-archae and eubacteria are different because hte cell walls of eubacteria contain peptidoglycan and archaea only live in extreme environments (methanobacteria or solfolobus bacteria)
What are obligate aerobic bacteria?
bacteria that requires oxygen for metabolism
what are obligate anaerobic bacteria?
bacteria requires no oxygen for life processes and metabolism
what are facultative anaerobic bacteria?
bacteria that can metabolize with or without oxygen
How are bacteria pathogens?
-they can eat cells, causing infected tissueas to decay, and
release toxins into our tisuses
what do antibiotics do?
they block the growth and reproduction of bacteria
what is the anatomy of a virus?
- primarily a protein “ capsule” (CAPSID) that contains DNA, with other body parts that assist in movement.
what is the anatomy of bacteria?
classic prokaryote- no cells, no nucleus just cell membrane nad circular dna
why are viruses not considered living?
-They lack cells
-they do not metabolize, grow , or develop
-they cannot reproduce independently
what are the steps of the lytic cycle and what kind of virus causes the lytic cycle?
-bacteriophage
1. virsues use proteins on their surface to bind to receptors on a host cell
- Viral genetic information(DNA or RNA) is “injected” into the host cell
The host cell’s ribosomes stop translating their normal proteins and translate the viral genome, creating more viral phages
The cell lyses (bursts) releasing more phages into the system, creating an exponential increase over a short number of generations
What are the steps of the lysogenic cycle?
-a virus injects its DNA into a host cell and the DNA incorporated into the cell’s genome. The DNA remains in the genome until it is activated by a some external factor, such as uv, stress, cell damage, or fever that triggers the cell to release proteins that trigger the cell to release an enzyme that cuts it from the host cell DNA and hijacks the cells ribosomes and causes the cell to reproduce the virus.
-then, the lytic cycle occurs
what is zoonosis?
an infectious pathogen that has EVOLVED to EFFECTIVELY spread from animals to humans
what is an epidemic? How long do they usually last?
-an epidemic is a sdisease that is confined to a small area and infects a large number of hosts in a short amount of time
-they are usually short lived because they are confined to a small population, which eventually develops immunities, or if is a viral infection, the virus will die off because there are no longer hosts.
what is an endemic?
a diesaese that is commonly present in a population, generally at low frequencies
-often due to the proximity of a host to a reservoir of the pathogen
