L1 and L2: Intro, Functional Anatomy, and Life Cycle Flashcards
True or False: Prokaryotes lack a nuclear membrane and contain a single, circular molecule of DNA
True
True or False: Eukaryotes have a nuclear membrane and use mitosis for both division and sexual repro
False - while eukaryotes do have nuclear membranes, they use mitosis for division and meiosis for sexual repro
How do prokaryotes divide? sexually reproduce?
Prokaryotes divide via: binary fission
and use horizontal gene transfer for repro
True or False: prokaryotes have membranes that CONTAIN sterols
False - prokaryotes have membranes that usually LACK sterols
50S, 30S, and 70S are found in ____ while 40S, 60S, and 80S are found in ____
50S, 30S, and 70S = Prokaryotes
40S, 60S, and 80S = Eukaryotes
Compare respiratory system in prokaryotes vs. eukaryotes:
Prokaryotes - plasma membrane
Eukaryotes - mitochondria
What type of cell wall is present in prokaryote vs. eukaryotes?
Prokaryote - peptidoglycan cell wall
Eukaryote - polysaccharide cell wall
True or False: eukaryotes have endospores
False - only prokaryotes!
True or False: Both prokaryotes and eukaryotes have cytoskeleton
True
(in eukaryotes: tubulin, actin, and IF)
How do flagella compare in prokaryotes vs. eukaryotes?
Prokaryotes: submicroscopic, single-repeating peptide
Eukaryotes: 9+2 arrangement of microtubules; microscopic
True or False: Gliding is present in both prokaryotes and eukaryotes
True
(in eukaryotes: amoeboid and pseudopodia)
True or False: Mycoplasma and Polio virus are two of the largest bacteria/virus while Bacilus anthracis and pox virus is one of the smallest
False - Mycoplasma and Polio virus are one of the SMALLEST while Bacilus anthracis and Pox Virus is one of the LARGEST
How can T. pallidum best be seen?
A. Darkfield microscopy
B. Bright field microscopy
A. Darkfield microscopy
Which stain will stain CELLS and not the extracellular medium?
A. Positive
B. Negative
A. Positive
Which stain will stain the EXTRACELLULAR MEDIUM and not the cells?
A. Positive
B. Negative
B. Negative
- Note: India ink for visualizing capsules
True or False: Gram positive cell wall/peptidoglycan layer retains crystal violet-iodine complex, while Gram negative wall does not
True
What are the steps of staining bacteria?
Crystal violet
Iodine (fixative)
Alcohol (decolorizer)
Safranin (counterstain)
Which two gram (+) bacteria stain Gram-variable and Gram(-) negative, respectively?
A. Listeria; Lactobacillus
B. Enterococcus; Gardnerella
C. Garderella; Mobiluncus
C. Garderella; Mobiluncus
True or False: 70S exists in both eukaryotes and prokaryotes
True - mitochondria in eukaryotes is 70S
What are the five steps to staining?
1) Fixation (heat)
2) Crystal Violet
3) Iodine Treatment
4) Decolorization (alcohol)
5) Counter stain (safranin)
You have a Gram (+) bacteria. However, after doing the staining procedure, it becomes red (not purple). Why is this?
Forgot to treat with iodine (therefore: bacteria did not get fixed with the primary stain)
In the second step of staining, crystal violet is administered to the bacteria, causing both gram positive and gram negative bacteria to turn ___
In the third step of staining, bacteria is treated with iodine, causing both gram positive and negative bacteria to turn ___
blue
purple
During the decolorization phase of staining, what color is the gram (+) bacteria? Gram (-) bacteria?
Gram (+) = Purple
Gram (-) = None
At the final stage of staining, what color is gram (+) bacteria? Gram (-) bacteria?
Gram (+) = purple
Gram (-) = red
What can occur if you over decolorize Gram (+) bacteria? What can occur if you under decolorize Gram (-) bacteria?
Gram (+) = translucent to red
Gram (-) = purple to purple
What are the three types of cellular arrangements that bacteria can take?
Diplococci (kidney bean or lancet) ; Chain ; Cluster
What are the five types of cellular morphology that bacteria can have?
1) Cocci
2) Rod
3) Helicoidal
4) Pleomorphic Bacillus
5) Endospore
What are the four medically significant gram (+) bacteria that end in -coccus?
1) Strepto
2) Staphylo
3) Entero
4) Peptostrepto
True or False: Clostridium is a medically significant gram NEGATIVE bacteria
False - clostridium is a medically significant gram (+) bacteria
What are the four medically significant gram (+) bacteria that end in -bacterium?
1) Corynebacterium
2) Bifidobacterium
3) Propionibacterium
4) Cutibacterium
What are the two medically significant gram (+) bacteria that end in -cillus?
Bacillus and Lactobacillus
True or False: Both Gardnerella and Mobiluncus are structurally gram (+)
True
What are the three medically important “kidney bean” shaped GRAM NEGATIVE diplococci?
1) Neisseria
2) Moraxella
3) Veillonella
True or False: This is a gram (+) bacteria diplococci, known as N. gonorrhoeae
False - while this is N. gonorrhoeae - it is a gram negative diplococci
Which medically important “lancet-shaped” diplococci is this?
A. Listeria
B. Neisseria
C. Streptococcus pneumonia
C. Streptococcus pneumonia
True or False: This is an acid fast positive (pink) bacteria, which utilizes a: Carbol Fuchsin/ Ziehl-Neelsen stain
True
Mycobacteria and Nocardia are: _____
A. Gram (+) Bacteria
B. Gram (-) Bacteria
C. Viruses
D. Endospore Formers
E. Acid-Fast Bacteria
E. Acid-Fast Bacteria
Mycobacteria and Nocardia are: _____
A. Gram (+) Bacteria
B. Gram (-) Bacteria
C. Viruses
D. Endospore Formers
E. Acid-Fast Bacteria
E. Acid-Fast Bacteria
Clostridium and Bacillus are: ____
A. Gram (+) Bacteria
B. Gram (-) Bacteria
C. Viruses
D. Endospore Formers
E. Acid-Fast Bacteria
D. Endospore Formers
True or False: This is an example of bacterial endospore formers
True
Which of the following gram-negative comma (vibrio) shaped bacteria is shown?
A. Vibrio
B. Helicobacter
C. Campylobacter
B. Helicobacter (H. pylori)
Which of the following gram-negative comma (vibrio) shaped bacteria is shown?
A. Vibrio
B. Helicobacter
C. Campylobacter
C. Campylobacter
Which of the following gram-negative comma (vibrio) shaped bacteria is shown?
A. Vibrio
B. Helicobacter
C. Campylobacter
A. Vibrio (V. cholera)
Bipolar staining is used and the bacteria have a safety-pin appearance. What two features can you determine about this bacteria given these facts?
A. Gram positive, bacillus
B. Gram positive, cocci
C. Gram negative, rod
D. Gram negative, helicoidal
C. Gram negative, rod
Which gram negative, rod-shaped bacteria caused the plague?
Which gram negative, rod-shaped bacteria can arise via animal bites?
Plague - Yersinia pestis
Animal bites - Pasteurella
True or False: E.coli and Klebsiella are rod shaped, gram (+) bacteria
False - while they are rod shaped, they are gram (-)
Identify the following stains:
Which of the following is shown?
A. Streptococci (chain)
B. Staphylococci (cluster)
B. Staphylococci (cluster)
Which of the following is shown?
A. Streptococci (chain)
B. Staphylococci (cluster)
A. Streptococci (chain)
True or False: Both Staphylococci and Streptococci are gram positive bacteria
True
___ is shown to be a very short rod
Coccobacillus
What type of arrangement does Klebsiella, a gram negative, rod shaped bacteria, have?
A. Chain
B. Single
B. Single
What type of arrangement does Bacillus have?
A. Chain
B. Single
A. Chain
True or False: Diptheroids are thin-branching filamentous rods
False - diptheroids are club-shaped rods
Which of the following is shown:
A. Corynebacterium
B. Nocardia
C. Actinomyces
D. Vibrio
A. Corynebacterium
This bacteria is a thin-branching, filamentous rods. Given this, which of the following is it most likely to be?
A. Coccobacillus
B. Actinomyces
C. Corynebacterium
D. Nocardia
B/D
True or False: Borrelia and Treponema are spirochetal shaped
True
True or False: This a curved rod (Vibrio)
False - it is spirochetal (treponema)
True or False: H. influenzae is pleomorphic bacillus, meaning it varies in size and shape
True
Which three features make up the bacterial envelope?
1) Capsule
2) Cell wall - peptidoglycan
3) Cell membrane - cytoplasmic/plasma membrane
Which three features are sometimes present in a bacterial cell?
Plasmic, Capsule, and Flagella
___ are extrachromosomal elements found intracellularly in bacteria
plasmids/prophages
True or False: Bacterial chromosomes are single, circular, and double-stranded
True
True or False: Intracellular bacteria structures are monomeric units (Type II-T independent antigens)
False - cell surface structures (such as: flagella, pili, or the capsule) are monomeric units (therefore: Type II-T independent antigens)
Which bacterial structures are also known as H antigens?
Which bacterial structures are also known as K antigens?
Flagella = H antigens
Capsule/slime layer = K antigens
What are the three primary functions of pili?
Adherence, motility, and anti-phagocytic
(also conjugation, sometimes)
True or False: Type IV Pili is important for gliding and twitching motility
True
What are three types of exopolysaccharides that can be used to create a capsule/slime layer?
1) Simple sugar molecule
2) Complex polysaccharides
3) D-glutamic acid
True or False: D-glutamic acid is used to form a polypeptide capsule in B. anthracic
True
Three functions of capsules and biofilm?
1) Adherence to host tissue and surface - e.g catheters/moving solutions
2) Antigen used to identify agent in serodiagnosis
3) Protection
a. Anti-phagocytic
b. Serum factors
c. Antibodies
d. Antibiotics
True or False: The H antigen is important for motility and chemotaxis
True
___: A protected structure of bacterial cells/microcolonies enmeshed in mucoid exopolysaccharide adhering to a wet surface
Biofilms
True or False: Bacteria in biofilms undergo a phenotypic change and persist in the presence of antimicrobial agents that they are normally susceptible to
True
True or False: Both Gram (+) and Gram (-) bacteria have a cell membrane
True
Typically the cell membrane of prokaryotes lack sterols, except which four prokaryotes?
(hint: AHEM)
A-Anaplasma
H-Heliobacter
E-Ehrlichia
M-Mycoplasma
True or False: In both gram positive and gram negative bacteria, the cell membrane is differentially permeable (to nutrients) and membrane transport exists for nutrients that are not permeable
True
Where is the site of septum formation for cellular replication?
cell membrane and plasma membrane
The peptidoglycan layer in the Gram positive cell wall is much ___ than the Gram negative cell wall
thicker
Polysaccharides are covalently linked to the peptidoglycan layer in the ____ cell wall, not in the ____ cell wall
Gram positive; gram negative
True or False: Lipid-containing molecules anchored in the cell membrane extend through the peptidoglycan layer in Gram negative cell walls, but not Gram positive cell walls
FALSE - lipid containing molecules anchored in the cell membrane extend through the peptidoglycan layer in GRAM POSITIVE CELL WALL (not in gram negative cell wall!!)
Which of the following cell walls contains an outer membrane with LPS?
A. Gram positive cell wall
B. Gram negative cell wall
B. Gram negative cell wall
Which of the following cell walls contains the periplasm where the peptidoglycan layer is located?
A. Gram positive cell wall
B. Gram negative cell wall
B. Gram negative cell wall
Label the following structures found in the Gram (+) bacteria:
Label the following structures found in the Gram (-) bacteria:
True or False: The cell wall/peptidoglycan of bacteria act as virulence and toxicity factors, as well as antigens
True
Which type of bacteria is O-antigen found in?
Gram (-)
____: site where differential staining occurs during gram staining
A. Cell membrane
B. Cytoplasm
C. Cell wall
C. Cell wall
Which bacterial structure prevents cell bursting via: osmotic forces and provides mechanical strength and rigidness?
Cell Wall
Penicillin is not effective is bacteria that lack peptidoglycan, such as ____
A. Bacillus
B. Staphylococcus
C. Mycoplasma
D. Streptococcus
C. Mycoplasma
True or False: Only Gram (+) Bacteria possess peptidoglycan
False - both gram positive and gram negative bacteria posses peptidoglycan
_____ structure: fabric shell/mesh-like layer/crystal lattice structure encasing the cell
Murein (peptidoglycan) structure
Peptidoglycan is made of a network of polymers, each consisting of repeating units containing _____ and ______
N-acetylmuramic (NAM) and N-acetylglucosamine (NAG)
___ acts on the aminosugar backbone of peptidoglycan
Lysozyme
How are N-acetylmuramic acid (NAM) subunits on different strands crosslinked?
Via peptide stems (amino acid side chains)
- provides mechanical strength and prevents cell bursting
True or False: In peptidoglycan, the cross-linkage via: peptide stems provides mechanical strength and prevents cell from bursting via: osmotic pressure
True
Gram ____ cell wall consists of a periplasm and outer membrane
Gram negative
The periplasm contains the ___ layer, which is only 1 layer thick
peptidoglycan
True or False: LPS is unique to the outer membrane of Gram positive bacteria
False - LPS is unique to the outer membrane of Gram-negative bacteria
What feature of Gram (-) bacteria allows them to be resistant to dyes, hydrolytic enzymes, and detergents?
Outer Membrane
How does the structure of peptidoglycan vary between bacterial species?
1) peptide side chain composition
2) bridge composition
3) chemical modification of amino acid
Which amino acid is the bridge in the peptidoglycan for Staphylococcus aureus?
Glycine
Why are gram positive bacterias susceptible to dyes, detergents, hydrolytic enzymes?
Lack OM
Major function of periplasm?
Osmotic protection
- nutrient uptake
- chemotaxis
True or False: OM is composed of lipopolysaccharide and phospholipid
True
True or False: LPS is an exotoxin
False - endotoxin
True or False: N. meningitis, N. gonorrhoeae, H. influenzae, and Haemophilus lack O-antigenic chain
True
What are the four important structures that make up the LPS in gram negative bacteria?
1) Lipid A - disaccharides, phosphate groups, FA
2) Core polysaccharide - namely: KDO
3) Terminal polysaccharide - very specific
4) LOS
True or False: LPS is chromosomally encoded and can induce a systemic inflammatory response syndrome (SIRS) and act as an exogenous pyrogen due to its broad specificity
True
True or False: LPS forms toxoids and is heat stable, even after autoclaving
False - LPS does not form toxoids; however it is heat stable, even after autoclaving
How can you detoxify LPS?
Burning or oxidation, which disrupts Lipid A
___ is heat labile, meaning it can be inactivated via 10 minutes of boiling
Exotoxin
LPS an an important immunomodulator that can initiate SIRS, which can lead to ______
distributive shock
Four clinical manifestations of SIRS?
temperature
tachy
tachypnea
leukocytosis or leukopenia
What indirect effects can be mediate via LPS binding to LBP?
1) Surface bound CD14 - initiates signal transduction via TLR on macrophages + signal transduced through cytoplasm to the nucleus
2) Soluble CD13 receptor present in serum, which then binds to endothelial cells
SIRS + a UTI suggests:
A. Sepsis
B. Severe Sepsis
C. Septic shock
A. Sepsis
Sepsis + Organ Failure suggests:
A. Distributive Shock
B. Septic Shock
C. Severe Sepsis
C. Severe Sepsis
Severe sepsis + refractory hypotension suggests:
A. Septic shock
B. Distribute Shock
C. Sepsis
A. Septic shock
What causes Distributive Shock (DS) - warm shock/hypovolemic shock?
LPS activates macrophages and binds to the hypothalamus
Non-blanching rash (petechial and purpuric rashes) and fever suggest ____ due to LPS activation of macrophages and binding to hypothalamus
distributive shock
- more specifically: DIC (disseminated intravascular coagulation)
Which two tests can be used to detect LPS?
LAL (limulus amebocyte lysate) test or MAB against LPS
True or False: Distributive shock causes drop in blood pressure due to vascular obstruction
False - due to loss of fluid from vascular system
Endotoxin (LPS) initiates/activates SIRS by binding to ___
LBP (LPS binding protein)
True or False: Gram positive cell wall has an outer membrane and LPS/Endotoxin
False - it does not
Which gram cell contains a thick peptidoglycan cell wall, teicoic acid (covalently bound to peptidoglycan) and lipoteichoic acid?
Gram(+) cell wall
True or False: The teichoic acid and lipoteichoic acid of the gram positive cell wall can extend beyond the peptidoglycan
True
What is the reason for differential staining in gram positive vs. negative cells?
Peptidoglycan is found in greater amounts in the gram (+) bacteria and there is more extensive cross-linkage of muramic acid’s peptide side chain
What are two ways in which the peptidoglycan in gram (+) cell walls is similar to LPS in gram (-) cells?
1) Can induce TNF-a and IL-6
2) Can cause hypotensive shock
True or False: Teichoic acids have a role in adhesion and anti-phagocytosis, like LPS
False - LIPOTEICHOIC ACID has a role in adhesion and anti-phagocytosis, like CAPSULE and PILI
True or False: Both LPS and Teichoic Acids activate complement (alternate pathway) and can initiate hypotensive shock
True
True or False: Disseminated Intravascular Coagulation (DIC) is limited to gram positive and gram negative bacteria
False - it is NOT Linked to these only
Detection of pathogens through a particular binding pattern, known as ______, which induce specific transduction pathways
PAMP’s
Peptidoglycan, teichoic acid, LPS, and CpG nucleotides are all ____
PAMP’s
Bacterial spores (endospores) are only found in which bacteria?
Gram positive
Bacillus and Clostridium are both _____
endospore-formers
____: Heat, desiccation, and chemical resistant organisms that can remain dormat for decades until favored conditions are present
Endospores
What are the stages of bacterial spore formation?
Forespore -> formation of cortex -> formation of coat -> endospore -> free spore
Why are mycobacterium and nocardia considered to be atypical bacteria?
Cell wall is made of mycolic acid (basis for acid fast stain)
____: an atypical bacteria that is wall-less and pleomorphic (lacks peptidoglycan); cell wall is stabilized by sterols
A. Chlamydia
B. Mycoplasma
C. Nocardia
D. Mycobacterium
B. Mycoplasma
____: an atypical bacteria that has gram negative wall architecture, but minimal peptidoglycan
A. Chlamydia
B. Mycoplasma
C. Nocardia
D. Mycobacterium
A. Chlamydia
