Week 2 Flashcards
Taxonomy
classifying or categorization of living organisms
nomenclature
system of names or terms
How is DNA packaged?
in chromosomes
What is the smallest segment of DNA?
a gene
What are the functions of lipids?
- cell membrane structure
- energy (storage)
- protection (cushion)
What are phospholipids?
they are polar on one end and non polar on the other
fat is non polar
What is the function of amino acids
- work (action)
- structure
- cell recognition
- energy (chemical reaction)
What are the functions of carbohydrates?
- energy (fuel)
- structure
- cell recognition
How many carbons does a carbohydrate have?
6
Long chain carbs are ______.
starches
What microorganisms are acellular?
viruses
prions
What microorganisms are cellular?
prokaryotes (bacteria)
eukaryotes (animal cells, plat cells, fungi, protozoa)
What types of microorganisms are in the category of prokaryotes?
bacteria
What types of microorganisms are in the category of eukaryotes
animal cells
plant cells
fungi
protozoa
What does a typical bacteria cell contain?
glycocalyx cell wall cell membrane cytoplasm ribosomes neucleoid
What do typical eukaryotes cells contain?
(more complex)
- cell wall
- cell membrane
- vacuoles
- peroxisome
- mitochondria
- chloroplasts
- golgi complex
- ribosome
- nucleus (nucleolis, chromatid, & nuclear membrane)
The major similarities between prokaryotes and eukaryotes?
- cytoplasm in the cell
- ribosomes through out the cell
- DNA is the genetic material
- cell (plasma) membrane
What are the major differences between prokaryotes and eukaryotes?
PROKARYOTES - no nulcleus - single chromosome - no organelles - complex cell wall - smaller EUKARYOTES - contain nucleus - multiples chromosome - contain organelles - single or no cell wall - larger
What is proposed in the 5 Kingdom system of taxonomy?
Robert Whittakes proposes organizing all organisms into kingdoms
- monera (prokaryotes)
- protista (eukaryotes)
- plantae
- fungi
- animalia
What is within the monera kingdom
bacteria
What is in the protista kingdom?
protozoa, slime molds
What is in the fungi kingdom?
mushrooms, molds, yeasts
What is in the plantae kingdom?
plants, algea
What did Carl Woese propose for taxonomy?
3 domains
- bacteria
- archaea
- eukarya
When classifying humans what are the subgroups listed?
Kingdom- animilia Phylum- chordate Class- mammalia Order- Primates Family- Hominoidea Genus- Homo Species- Sapiens
How can homosapiens be broken down?
Homo is the genus and sapiens is the species
What is homosapien an example of?
binomial nomenclature
Binomial nomenclature.
uses genus and species to name
Genus.
2 or more species with similar morphology
Species.
groups of organisms with similar genetics
How do you use binomial nomenclature?
Genus first (first letter capitalized) Species Second ( all lowercase) - both words underlined or in italics
How can you abbreviate binomial nomenclature
Just use the first letter of the genus and a period
What eukaryote doesn’t use binomial nomenclature.
Viruses
Strains.
microbes within a species with some genetic change (e.g. O157: H7)
What unit is µm?
micrometers
how many µm in a mm?
1000
How many nm in a µm?
1 000 000
Typical size of a bacterium?
1-5 µm
Typical size of a virus?
50-250 nm
What is bigger, a virus or a bacterium?
bacterium
Compound light microscope.
100-1000x magnification
can see single cells (not viruses)
Electron Microscope.
20 000 000x plus
- uses different wave lengths of light to see different things
(needed to see viruses)
What are the 3 types pf electron microscopes?
- Scanning electron microscopy (SEM)
2. Transmission electron Microscopy (TEM)
Scanning electron microscopy (SEM)
this electron microscope images look 3 dimensional
Transmission electron Microscopy (TEM)
Image goes right through (can see organelles)
What are Fluorescence Microscopy used for?
bacterial or viral identification
What do classifications lead too?
identification
What are some identifying characteristics?
- cell morphology (shape or arrangement)
- staining reaction
- motility
- colony
- morphology
- colony morphologu
- atmospheric requirements
- nutritional requirements
- biochemical metabolic activities
- specific enzymes
- pathogenicity
- genetic composition (15s RNA
Bacterial morphology.
cell shape and arrangement
Rod-shaped bacteria?
bacillus (pl. bacilli)
Spherical or round bacteria?
coccus (pl. cocci)
Curvey or wavy bacteria?
curved rod- vibro
rigid wave- spirillum (pl. spirilla)
fexible wave- spirochete
Chains of bacteria.
strepto-
Pairs of bacteria.
dilo-
grape like clusters
staphylo-
What are staining techniques used from?
- visualize bacteria
- identify bacteria
- differentiate different kinds o f bacteria
What are 3 major staining techniques?
Simple stain
Gram stain
Acid-fast stain
What is a simple stain?
stain all bacteria same colour (basic positive dye because most parts of bacteria are negatively charged)
What is a gram stain?
differentiate types of cell wall (+/- gram)
What is acid-fast stain?
identifies mycobacteria
Smear.
place a drop of bacteria sample on a slide
What is common to all stains?
- smear
- heat fix the sample (kills bacteria, stick to slide)
When would you use a simple stain?
when you want to know shape and arrangement
Gram positive appears…
clustered
Gram negative appears…
separate
Steps of gram stain.
- smear
- heat
1. crystal violet
2. iodine
3. alcohol wash
4. safranin (aka counterstaining)
What colour are gram negative bacteria after a gram stain?
orange-red
What colour are gram positive after gram stain?
blue-purple
Gram postive bacteria cell wall is composed of?
cell wall made of protein and carbohydrates
Gram negative cell wall is composed of?
outer membrane (lipids/proteins) inner layer before membrane (protein/carbs)
Which on has the extra layer in their cell wall, gram + or gram -?
gram negative
Examples of Gram +ve bacteria
staphylococcus aureas
susceptible to penicillin
What is staphylococcus aureus
susceptible to?
PENECILLIN
Example of gram -ve bacteria
Escherichia coli
(susceptible to tetracuclines)
-release toxins from membrane
What is E. coli susceptible to?
tetracycline
Chlamydia trachomitis is …
gram negative cocci
What is the most common bacteria in the world to cause an STI?
Chlamydia trachomatis
gram -ve cocci
Steps to an acid fast stain.
- smear
- heat
1. read stain
2. heat (to penetrate)
3. acid/alcohol wash
4. Blue stain
Acid fast stains are used to identify ______ bacteria.
Mycobacteria
Ex. TB causing
Mycobacerium tuberculosis
What is in the bacteria envelope?
glycocalyx
cell wall
cell membrane
What is Glycocalyx?
sticky layer of polysacchraides & small protiens
What is the glycocalyx for?
protection, adhesion, water balance
What types of bacteria have glycocalyx?
rods (bacillus) and sphere (coccus) shapes
What is an example of bacteria with a glycocalyx?
Haemophilus influenza
Describe Haemophilus influenza.
Causes meningitis
- difficult for antibiotics to penetrate the glycocalyx
- death rate in treated meningitis = 20%
What is the death rate in treated H. influenza?
20%
Glycocalyx capsule.
thick and tightly bound
Glycocalyx slime layer.
thin and flowing
What is an example of a bacteria with a slime layer?
Pseudomonas aeruginosa
Pseudomonas aeruginosa.
opportunistic bacteria
- causes UTI and lung infections
- has slime layer
What do colonies of glycocaylyx-covered bacteria from when they come together?
biofilms
What is the problem with biofilms?
they make it challenging to kill bacteria with macrophages andantibiotics
Where is a common place to find biofilms?
on catheters
Describe bacteria cell wall.
Complex Semirigid structure Responsible for cell shape Protects against ressure changes Composition and thickness varies
Describe gram positive bacteria cell walls.
Made of protein and carbohydrates (called peptoglycan) and Teichoic acid)
What is teichoic acid?
part of gram positive cell walls
- gives stability
- made of phosphate and alcohol
- highly negatively charged
- antigenic
Antigenic.
substance that stimulates production of antibodies
Describe gram negative bacterial cell walls.
Outer membrane
Lipopolysaccharide
(LPS-endotoxin, antigenic)
(lipoprotein & liposacharide)
Peptoglycan- Periplasmic region
Cell membrane below
What is Lipopolysaccharide?
part of gram negative cell wall
- endotoxin
- antigenic
Endotoxin.
toxin inside a bacterial cell that is released when the cell is digested
Which cell wall is thicker, gram +ve or gram -ve?
gram +ve
Which has an outer membrane and periplamic region, gram +ve or gram -ve?
gram -ve
Which contains teichoic acid, gram +ve or gram -ve?
gram +ve
Which contains LPS, gram +ve or gram -ve?
gram -ve
What are cytoplasmic contents of bacteria?
ribosomes
inclusion bodies
single chromosome
plasmids
What are plasmids?
circular pieces of DNA, not essential for life, carry antibiotic resistance, act as ‘emergency’ genetic material
What are bacterial endospores?
dormant/resistances stage of certain bacterial cells
- NOT a form of reproduction
- form when nutrient and moisture are low
- spores EXTREMELY RESISTANCE
What is a spore coat made of?
protein that doesn’t stain
What are some diseases caused by sporeformers?
- antrax (Bacillus)
- tetanus (Clostridium)
- gas gangrene
- botulisms
What are flagella made of?
rigid protein subunit called FLAGELLIM
Describe flagella.
long, thread like appendages on some bacteria
- allow motility
- made of flagellim
How fast des the filament of a flagella rotate?
600rpm
10x per second
How fast can bacteria move?
50 µm/s
What is the process by which bacteria move?
chemotaxis
Describe chemotaxis.
the process by which bacteria move; attracted to favourable conditions and repelled from unfavourable
How do bacteria with flagella move?
runs (counter clockwise) and tumbles (clockwise)
When conditions are unfavourable how do bacteria move?
long tumbles and short runs
When conditions are favourable how do bacteria move?
short tumbles longs runs
the more energy from conditions the longer the run
Describe Pili.
many, short, hairlike appendages
- pili are made of protein called PILIN
- help bacteria ATTACH, and TRANSFER GENETIC MATERIAL
What do pili do?
- ATTACH to surfaces or other cells (called FIMBRIAE))
2. TRANSFER DNA from one bacterium to another (use SEX PILI) this process is called CONJUGATION
How do bacteria reproduce?
binary fission
What is the usual rate of reproduction for bacteria>?
20-30 minutes
Generation doubling time.
time in minutes for a population to double (logarithmic or exponential growth)
What are the stages of logarithmic growth of bacteria?
- Lag phase has few cells
- Exponential growth phase lots of live cells few dead cells
- Stationary cells has half live cells half dead cells
- Death phase most die off but some remain viable
What are the growth requirements for pathogens to go?
35-42 C
pH 7.0-7.5
What temp. do psychrophile grow at?
0-20 C
Example of psychrophile.
Listeria
What temp. do mesophile grows at?
20- 40 C
Example of mesophile
ecoli
What temp. do thermophiles grow at?
40-90 C
Example of a thermopile.
hot springs, hydrothermal
Aerobes.
require oxygen
Anaerobes.
Do NOT require oxygen
Benefit of oxygen.
excellent energy-producing molecule
Flaw of oxygen.
generates free radical toxins
Aerobes must be able to break down ___ ______ or die.
free radicals
Facultative anaerobe/aerobes.
can take or leave oxygen
example of facultative bacteria.
E. coli
facultative aerobes
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