bacteria & viruses

Eubacteria

-cell wall determined shape and contains a protein called peptidoglycan

-have a cell membrane

-live almost everywhere (not very extreme places) land, human body

Archaebacteria

-cell walls have different proteins than eubacteria

-DNA indicates they may be more like eukaryotes than eubacteria are

-mostly in extreme environments

identifying bacteria

-shape: bacilli, cocci, spirilla

-how they obtain energy: heterotrophs & chemoautotrophs

-their ability to use or be harmed by oxygen

-motility: flagella or can’t move alone

-gram staining: (gram-positive:not as resistant to antibiotics & gram-negative: more resistant to antibiotics)

binary fission

-DNA replication followed by cell division

-can happen as rapidly as once every 4 minutes

conjugation

-hollow bridge forms between 2 bacterial cells and genetic information is swapped to increase genetic diversity in populations of bacteria

endospores

-formed during unfavorable conditions, allowing the bacteria to survive

-enclose the DNA and some cytoplasm (remain dormant for months or years)

viruses

-made of nucleic acid (DNA or RNA) surrounded by a protein coat called capsid

-much smaller than a cell

-can’t do anything if they are not inside a host cell

-only purpose is to infect cells in order to reproduce

-most are highly specific to what host they infect

viral infection

-capsid protein spine to receptors on the cell surface and “trick” the cell into allowing it inside

-viral genes are expressed in the whole cell transcribed and translates them into viral capsid proteins

-host cell makes copies of virus, and is destroyed

how DNA and RNA affect viral infection

-viruses with RNA attempt to mutate→ Evolve quickly→ hard to develop vaccine

-viruses with RNA don’t mutate quickly→ Have vaccines to prevent infection

lytic infection

-virus hijack a cell and inserts, the viral DNA into the cell

-the cell copies, the viral DNA and ends up making new viruses

-the cell breaks open releasing new virus→ go invade more cells

lsyogenic infection

-the virus inserts its DNA into the cells DNA and the cell continues with its normal activities

-as the cell copies itself it also copies, the viral DNA, which is hiding and waiting in the cell

-eventually the barrel DNA becomes activated and it changes into lytic infection

pathogens

-a virus,bacterium, or microorganism that can cause disease

antibiotics

-can treat bacterial infections

-cannot treat viral infections

vaccines

-try to prevent infections, especially viruses

-weekend or dead pathogen is injected into the body to teach immune system. How to fight it off without actually getting you sick.

classification

-system that allows us to group living things in a logical way

-universal

taxonomy

-science of classifying organisms and giving them universal names

binomial nomenclature

-system of naming

-each species gets a 2-part scientific name

-1st word: Genus (capitalized)

-2nd word: species (lower case)

-always written in italics or underlined

linnaeus

groups by appearance

evolutionary classification

-grouping based on evolutionary history

-phylogeny: the study of evolutionary relationships among organisms & supported by cladistics

-The use of shared inherited characteristics often through DNA sequences to determine relatedness

cladogram

-a diagram that shows the evolutionary relationships among a group of organisms