kingdoms, viruses, pathogens Flashcards
do bacteria have chloroplasts
no
Transcription/translation occurs in same compartment of ___ everyone else does it in diffferent compartmetns
bacteria. note that even protists do transcription and translation in diff compartments
what component is in cell walls
peptidoglycan
flagella in eukaryotes vs bacteria
9+2 for cilia /flagella in eukaryotes, protists, plantae. Bacteria have their own special flagella- rotary motor
three domains of living things
bacteria, archae, eukarya
Pathogen
something that causes a disease
Archaea
primitive type cells. Different enough that they are NOT closely related to other bacteria- but they ARE prokaryotes. No nucleus. Also called ‘extremophiles’ because they like to live in hot springs, glaciers, etc. no effect on health/disease. Own kingdom.
explain how ancestral eukaryotes evolved
an archae type picked up a mitochondria . Gives rise to fungi, animalia, etc. the archae that picked up photosynthetic bacteria became chloroplasts-> plants, protists
how many kingdoms are there
6
why are viruses not living?
They MUST be inside of a host cell to replicate- cannot do it on their own.
- Have no metabolism
- No oxygen consumed, no ATP used, etc
lifecycle of a phage- lytic vs lysogenic?
- Once DNA has been injected, could go a couple of ways
- Lytic cycle: take over cell right then and immediately start transcribing/translating viral genes. breaks open host cells
- Lysogenic cycle: turn off repressor proteins, repressor protein says ‘don’t break open!’- has potential to be converted back into viral factory stage. Has potential to break open and produce new virus.
replication cycle DNA virus
1) Attachment (Adsorption)
2) Penetration
3) Uncoating
4) Targeting
5) Gene expression.
- synthesis of viral mRNA (transcription)
- synthesis of viral proteins (translation)
6) Genome replication
7) Virion assembly/maturation
8) Release of new infectious virus
- lysis : breakdown of cell membrane and release of virus
- budding: viruses “bud” through cell membrane and are released without necessarily killing the cell. Viruses acquire envelopes (membranes) during this process.
Replication cycle for RNA virus
- Carries its own reverse transcriptase- so it can copy its own RNA and animal cells do not have any reverse transcriptase in them
- Note: reverse transcriptase critically important in cloning as it creates cDNA. It’s the only enzyme that will use RNA as a template. Howard Temin + David Baltimore Nobel prize for this.
- Binds 2 cell. HIV viruses only attack T-cells. Have marker on surface called CD4. It’s the surface marker that hiv viruses recognize in order to bind to target cells.
- Copy RNA into double stranded dna. Why? Much more stable
- Double stranded dna inserts itself DIRECTLY INTO GENOME OF HOST CELL.
Once in host genome; transcription of DNA produces RNA’s that are the genome for an RNA virus. Same RNA gets translated by ribosomes and makes viral proteins, assemble new viruses, and then bud out.
difference between DNA virus vs RNA virus replication: genome
DNA virus not incorporating itself into genome
why do RNA viruses carry their own reverse transcriptase with them?
so it can copy its own RNA- animal cells do not have any reverse transcriptase in them
