Flashcards in Lecture 3 Deck (106):
(pro=before) DNA is not enclosed w/in membrane, chromosome is singular&circular, no membrane could organelles, single celled organisms only
Chromosome of prokaryotes exists w/ in ...
specific region of cell called nucleoid
(eu=true) DNA is contained w/in membrane bound nucleus, DNA is arranged as multiple chromosome, organelles are present and membrane bound
Eukaryotes can either her..
single celled or multicellular
protists, fungi, plants, animals (multicellular)
3 bacterial morphology
spherical (ex: streptococcus pyogene also known as strep throat)
rods (ex: escherichia coli also known as E.coli)
spiral (ex: treponema pallidum causes syphilis)
(sugar coat) gelatinous, sticky polymer, secreted from the prokaryote onto outside of cell wall. varied (some bugs make them other don't)
Glycocalyx can be composed of either..
polysaccaride, protein or both
When glycocalyx is made only of sugar its called an..
Glycocalyx capsule is when substance of glycocalyx..
is firmly attached to cell wall and organized
Glycocalyx slime layerwhen substance of glycocalyx
is disorganized and only loosely attached to cell wall
Capsules contribute to organisms virulence
by protecting from phagocytosis, and against dehydration (holds nutrients inside cell)
ability to cause disease
Capsule stickiness allows the organism to..
adhere to and colonize host cells
Certain organisms such as Bacillus anthracis ca only cause disease if they are..
allows the bacterium to survive by attaching to diff surfaces w/in microbes environment
Cons of extracellular polysaccarides to other bacteria, catheters, implants, teeth, plant roots, water pipes etc..
this quality allows the bacterium to attach to them and thrive (hard to get rid of)
found on some prokaryotic cells, long filamentous and used for motility, need been to be produced, move in cork screw motion
3 primary parts of flagella
Filament of flagella
composed of circular flagellin protein forming helix around hallow core, not covered by sheath
Hook of flagella
made of different protein than the flagella, attached to basal body
Basal body of flagella
Anchors the flagellum to plasma membrane and cell wall
flagella distrbuted over entire cell surface, multiple flagella
single polar flagella
2 or more flagella at 1 or both ends of the cell. can describe multiple types of flagellar arrangements
tuft of flagella at each cell end
Flagellar proteins are used to differentiate ..
in between strings of diff bacteria
Flagella can rotate either..
clockwise or counterclockwise
Flagellar movement depends on..
movement in one direction for continuous period of time
abrupt or random changes in direction, result when flagella changes its direction
move away dangerous environments and toward favourable environments
movement toward chemical stimulus
movement toward light stimulus
Pili and fimbriae
hair like appendages (stick to walls to reproduce) that are shorter, thinner than flagella and not used for motility, found in many gram - bacteria (never +)
Pili/frimbriae on prokaryotes are wither
bacteria(gram - or +) or archaea
Bacterial cell can contain a few to hundreds, can be all over or only at poles
Frimbriae enables the bacterial cell to..
adhere to surfaces and other bacterial cells
Frimbriae allows bacterium to..
adhere and colonize, w/o frimbriae colonization cannot occur and disease doesn't occur
longer than frimbriae, only 1-2 per cell
pili filaments join 2 bacterial cells in order to transfer DNA in between them, direct port of passage for info
Bacterial cell wall
semi-rigid, complex and semi permeable, provides cell shape, prevents cell rupture, important means of classifying bacteria
Bacterial cell wall is composed of the polysaccharide..
polysaccarides composed of repeating disaccharides, very unique
Peptidoglycan chains are..
-layered on top of on another
-liked together by short polypeptides (creating lattice and strong cell wall resistant to osmotic changes)
Disaccharide unit is composed of..
-N-acetyl glucosamine (NAG)
-N-acetyl mermaid acid (NAM)
Gram positive cell wall contains..
thick layer of peptidoglycan outside of the plasma membrane
only found in gram + organisms, they hold everything together on top of membrane (toothpicks)
2 forms of teichoic acids
-wall teichoic acids
Wall terichoic acids
extend out from the peptidoglycan (only goes to the peptidoglycan)
connect the plasma membrane to the peptidoglycan (goes all the way to the lipid membrane)
Gram positive bacteria only have....
one membrane, plasma membrane. no top layer
Gram negative bacteria contain a..
plasma membrane and outer membrane
space between two membranes. filled w/ periplasmic fluid
Outer membrane of gram negative cell contains
Lipopolysaccharides lipid portion ..
toxic, referred to as endotoxin
Lipopolysaccharide polysaccharide portion..
composed of O sugars used to distinguish gram negative organisms
First step of gram stain
crystal violet applied, gram +'s and -'s appear purple while only the gram + is actually stained
Second step of gram stain
add iodine, gram + and gram - are both still purple
Third step of gram stain
add alcohol (a destain) which disrupts the outer membrane has washes away any crystal violet leaving gram + purple and gram - colorless
Final step of gram stain
Add safranin (counterstain) which is take up by gram - cells so the gram + are purple still while gram - are now pink
Peptidoglycan is a common target for both..
host defences (lysozymes in saliva) and chemotherapies (penicillin)
Plasma membrane composed of .. and provides a barrier in between ...
classic phospholipid bilayer; the intracellular and extracellular environments
Semi permeable barrier exists in a semi-fluid state where..
fluid enough that membrane proteins are able to move/perform function but sold enough to maintain cell shape
What disputes the plasma membrane
Cytoplasm composed of ..
75% water (cytozol)
amino acids, carbohydrates, nucleotides, enzymes, inorganic ions, nucleiod, ribosome,
Cytoplasm is ...
aqueous but thick and semi transparent
contains bacterial chromosome, no nuclear membrane, may have plasmids
small circular double stranded DNA molecules
non essential genes which can help bacterium to survive adverse conditions (antibiotic resistance)
where protein synthesis occurs, made of protein and ribosomal RNA
Ribosomes consist of 2 subunits
-50S subunit; large
-30S subunit; small
50S and 30S subunits come together to form..
Eukaryotic ribosomes are..
larger and heavier (80S) large subunit is 60S and small subunit is 40S
Why is it a perfect opportunity for antibiotics to target bacterial ribosomes
to execute selective toxicity, it can target the ribosome and will not cause harm to host cells
deposits of nutrient granules store for later use, serve basis for identification
Types of inclusion bodies include:
-lipid inclusions *
(*important NRG sourcE)
Endospores are only formed from..
special structures that allow bacterium to resist heat, desiccation, chemicals, and radiation
Endospore will remain ____ for long periods of time and leave ____ when..
dormant; dormancy; good growth conditions
very resilient and some can even survive boiling water for hours making them difficult to get rid of
Examples of spore forming bacteria include
First step in sporulation
bacterial cell replicates its DNA
Second step in sporulation
a septum forms diving the cell
Third step in sporulation
larger compartment engulfs the smaller forming foreshore within the mother cell
Fourth step in sporulation
peptidoglycan and other protective material forms around forespore (the spore coat)
Fifth step in sporulation
spore is free from mother cell
-algae (multi and unicellular)
plants and animal
Eukaryotic flagella and cilia
long and flexible, move in whip like motion, contain protein and cytoplasm, used for motility
Eukaryotic cell wall
not present in animal cells, structurally simple, composed of singly polysaccharide
Polysaccharide in algae and plants
Polysaccharide in fungi
Eukaryotic plasma membrane
same structure as prokaryotic, contain phospholipids, proteins, sterols
not in prokaryotes, cause eukaryotes membrane to be more rigid
Eukaryotes are often capable of..
endocytosis which engulfs particles outside cell and brings them inside
Eukaryotic cytoplasm located within..
boundary of plasma membrane but outside n clear membrane
Eukaryotic cytoplasm have complex internal structure called a ___ that ..
cytoskeleton; provides support/shape, acts to transport substance though cell, composed of protein filaments
Membrane bound organelles are..
absent in bacteria, structures w/ specialized function