unit 4; microbiology Flashcards
microorgansims
exist where these is life
in good conditions can reproduce every 15 mins
how do bacteria feed
through their surface area and the energy is stored in adp
how to get rid of bacteria
temperature-hot or cold, freezing, drying, preservatives and sterilization. PEOPLE GET IMMUNIZED
endspore
in poor conditions the bacteria become dormant and form a spore
resistant bacteria
if unneeded antibiotics are used it can create a resistant strain and they become resistant when they have a mutation in their ribosome that doesn’t allow the antibiotic to bind to it
humans create more wide spread diseases because we produce more garbage and pollution, put higher demands on the environment, travel from place to place
aseptic techniques in the lab (CHECK 6)
do not eat or drink in the lab clear off work area never open the plate (unless instructed to) handle with non writing hand wrap in paper towel and throw away
was hands with soap and warm water
bacteria domain
thick rigid cell walls that surround a membrane. the cell walls contain peptidoglycan
archaea domain
extreme environments, membranes contain unusual lipids the cell walls do not contain peptidoglycan
what is bacteria composed of
cell wall, (peptidoglycan), cell membrane, ribosomes, DNA,pili, flagellum
*pili
transfer DNA between bacteria because they make bridge like structures
*flagella
used for movement
4 ways we characterize bacteria
shape, chemicals in cell walls, way they obtain energy, how they move
shapes
coccus- spherical round
bacillus-pillshaped rods
spirilium- curly spirals
obtaining energy
heterotrophs-get energy from consuming organic matter
chemoheterotrophs-take in organic molecules for energy and carbon supply
photoheterotrophs-use sun for energy but also need to take in organic compounds
autotrophs- make own energy
photoautotrophs- use light and energy to convert carbon dioxide and water into carbon compounds and oxygen
chemoautotrophs-make organic molecules from carbon dioxide-do not need light as a source of energy
releasing energy
use cellular respiration, fermentation or both
obligate aerobes- must live in the presence of oxygen (tuberculosis)
obligate anaerobes- cannot live in the presence of oxygen
facultative anaerobe bacteria- can live with or without oxygen. if oxygen is present they use cellular respiration to make atp and if oxygen not present they use fermentation to make ate.
growth and reproduction of bacteria
reproduction is related to the environment of the bacteria
binary fission- asexual reproduction. divide and split into 2 daughter cells that are identical (mitosis)- stable and unchanging environment
conjugation- transfer of genetic information from one bacterium to the next. pili form a hollow bridge on the cell walls to connect. this is used in a changing environment and promotes diversity
endospore- these can remain inactive and dormant for months or even years. they contain DNA and cytoplasm. they occur in very harsh conditions and when conditions are favourable again they germinate
viruses
nucleic acids, proteins, and sometimes have lipids. they enter living cells, use the machinery of the infected cell to produce new viruses.
bacteriophage structure
they have a head which contains the DNA, then a tail sheath and tail fibres off of that
capsid
protein coat that surrounds the DNA in a virus. proteins enable virus to enter the host cell and bind to the receptors of the host cell
virus vs cell (7 things)
structure- virus has DNA or RNA inside capsid. cell has cell membrane, cytoplasm and eukaryotes have nucleus and organelles
reproduction- virus only inside host. cell independently grows and divides
genetic code- virus has DNA or RNA. cell uses DNA
Growth and development- virus has none. cells grow
obtain and use energy- virus no, cell yes
respond to environment- virus no, cell yes
change over time- virus yes, cell yes
virus infects host cell
inside the host cell the viral genes are expressed and cause the host cell to make new DNA. This happens when the viral DNA takes over cell organelles to make their own protein and DNA
viral specifity
viruses are very specific to the types of cells they can bind to. intimate connection of host cell and surface proteins and DNA. plant viruses can effect human cells but a mutation can occur and make a virus susceptible to other species.
lytic infection
- bacteriophage injects DNA into bacterium
- bacteriophage forms a circle
- bacteriophage takes over bacterium metabolism causing the synthesis of new bacteriophage proteins and nucleic acid
- protiens and nucleic acid assemble into new bacteriophages
- bacteriophages enzymes lyses bacterium cell wall releasing new bacteriophage particles
lysogenic infection
- bacteriophage injects DNA into bacterium
- bacteriophage DNA forms a circle
- bacteriophage DNA inserts itself into bacterial chromosome
- bacteriophage DNA (prophage) may replicate with DNA for many generations
- Prophage exits the bacterial chromosome and enter the LYTIC CYCLE
prophage
viral DNA that is embedded in the host cells DNA when activated it will remove itself from the host cells DNA and direct the synthesis of new proteins and DNA and produce new viruses
retroviruses
carries RNA instead of DNA and it causes the host cell to rewrite its own DNA. mRNA transcription- DNA makes copies of the gene into mRNA. but in a retrovirus the RNA is turned into DNA before the mRNA is transcribed.
viroids
effect plants and they are single strands of RNA
prions
infect animals ( including humans) only composed of protein and they can cause mad cow disease or cruetzfelt-jakib disease
AIDS
acquired immune deficiency syndrome caused by HIV( human immunodeficiency virus)- transmitted thru body fluid and can remain dormant for 10 years. its a retrovirus. they attack helper t cells so the body doesn’t know when the immune system needs to be turned on. AZT slows the growth.—- adenine joins with thymine- drugs special thymine fits with the viral adenine stopping it from continuing.
archetista
not alive and composed of nucleic acid, DNA OR RNA and sometimes lipids- only reproduce inside of living cells do not respire, grow or respond to stimuli
disease
a disease is any change other than injury that disrupts the bodies normal functions
caused by viruses, bacteria, fungi,animals, environment, protists, or inherited
pathogens
disease causing agents
how do bacteria produce disease
damage cells and tissue directly by breaking it down for food release toxins (poisons) that trade throughout the body and interfere with normal activity of the host
louis pasteur
germ theory of disease
bacteria cause disease
developed the process of pasteurization
robert koch
bubonic plague
bacteria transmitted by flees`
disease spread by
physical contact
contaminated food or water
vectors- animals that carry pathogens
antibiotics
destroy bacterias ribosomes so they cannot repair, grow or reproduce
over the counter drugs treat symptoms only
influenza vaccines
is a weakened form of the virus made in mass in chicken eggs