viruses & fungi

How many diff kinds of species a virus can infect

narrow = very few (1-2)

broad = many

what kind of cells a virus can infect (respiratory, etc)

-capsid surrounds genome. Made of protein

-some have envelope with spike protein for attachment

RNA or DNA

single stranded (ss) or double stranded (ds)

(-) oriented 3’-5’ or (+) oriented 5’-3’

-radial symmetry (circle)

-fixed size

-naked or envelope

-some have spike proteins for attachment

-helical symmetry

-helical tube around genome

-variable size → flexible

-size can increase based on genome

-no symmetrical form

-most flexible

-NO capsid, but HAS envelope

-has “core wall” under envelope (similar to cytoplasm in cells)

(example: flu)

-only infects bacteria

-DNA stored in head, tail used to attach & inject

-ALWAYS HAS DS DNA GENOME

when a virus evolves and mutant proteins no longer recognized by host antibodies → generates new strands of virus

-community: evolve to infect diff species → increase host range

-within a species: evolve to be more infectious → antigenic drift

-within an organism: evolve variants that resist meds → infect tissue

1. attachment to cell

2. penetration

3. synthesis of new material in cell

4. assembly of virus in cell

5. release virus

lytic = normal infection cycle

lysogenic = bacteriophage NA into host DNA during replication. slower. then a stimulus activates it and all cells with viral genes in DNA become infected suddenly

PROK ONLY

nucleus

nucleus

cytoplasm

when cell doesn’t die and lyse, instead virus keeps being made and released out of cell. EUK ONLY

when virus doesn’t produce virions for long periods. (ex. HIV or herpes). EUK ONLY

latent = EUKARYOTIC infection

lysogenic = PROKARYOTIC infection

when a host picks up a disease from 2 diff species at the same time. the 2 strains combine and make a new variant thats highly infectious

(ex. when a pig gets the flu from humans and bird at the same time)

if taken 24-48 hr after symptom onset

eukaryotic

cell wall =chitin, glucan (sugar), mannoprotein

cell membrane = ergosterol

multicellular, mold (& spores)

hyphae

conidia

-lung infection

-breathe in from spores

-greater affect ppl with lung problems (COPD, smoker, allergies)

-grows everywhere = soil, produce, mold on walls

single cellular, yeast

bread = saccharomyces

infectious = candida

yeast mouth infection

ergosterol & chitin since they are not found in humans