Bacterial Structure

Front 1

the cell envelope of bacteria contains what?

Back 1

cell wall, cell membrane, capsule, pili, and flagella

Front 2

how do archaea relate to humans and what distinguishes them biochemically from bacteria?

Back 2

some species are present in the digestive tract. They have no peptidoglycan and different membrane chemistry

Front 3

the 4 bacterial groups that are pathogenic are...?

Back 3

gram +, gram -, spriochetes, and chlamydia

Front 4

of the organelles that all eukaryotic cells contain, which are not present in bacteria?

Back 4

nucleus (and associated parts), ER, golgi, and mito

Front 5

how many proteins are found in the bacterial RNA polymerase? eukaryotic RNA poly?

Back 5

one. three

Front 6

branched filamentous bacteria resemble what?

Back 6

fungi

Front 7

bacilli can form what secondary characteristics?

Back 7

diplo, strep, and cocco (sphere like rod)

Front 8

mucoid colony appearance usually indicates what? waxy? thin and spread out? pigment?

Back 8

capsules. high lipid content possibly mycobacterium. high motility. protection against light thus not usually pathogenic

Front 9

compare gram pos with gram neg

Back 9

gram pos have thick peptigoglycan outer layer then membrane. gram neg have outer membrane of LPS then a periplasmic layer with a thin layer of peptidoglycan within it and then the cell membrane

Front 10

what proteins that can be possible virulence factors are found in the peptidoglycan layer of gram pos bacs?

Back 10

teichoic and lipoteichoic acids

Front 11

what is the significance of the periplasmic space in gram neg bacs?

Back 11

there may be virulence factors

Front 12

describe the color and results of a gram stain and what are some exceptions thatr make this test inaccurate?

Back 12

purple is pos while red is negative. dead or damaged orgs will stain red. orgs lacking peptidoglycan or mycobacteria with a waxy coating have inaccurate results

Front 13

what are the membrane lipids found in the bacterial cell membrane?

Back 13

PE, PG, cardiolipin, and sterols (ONLY in helicobacter and mycoplasmas)

Front 14

the chief role of the peptidoglycan layer in bacs is for what? what is its role in pathogenesis?

Back 14

resistance to osmotic stress. it has pyrogenic activity

Front 15

describe the chemical structure of peptidoglycan. what enzyme can disrupt it and how?

Back 15

repeating monomers of NAG and NAM connected by a B 1,4 link with a sugar backbone and peptide crosslinks. lysozyme disrupts the B 1,4 links.

Front 16

what two compounds in the chemical structure of peptidoglycan are never found in eukaryotes?

Back 16

NAM and DAP

Front 17

describe the structure and function of the LPS of gram negs.

Back 17

o specefic polysaccharide then core polysaccharide then the toxic lipid A. the oliogosaccharide side chain produces virulence. the core provides resistance to hydrophobic compounds. the outer LPS membrane prevents large compounds from entering. Divalent calcium and magnesium strengthen the LPS, but it is weakend by EDTA. It is toxic to humans. The extensive external size of the LPS reduces the interaction of external compounds to the lipid bilayer

Front 18

what does the LPS do to humans?

Back 18

activates B cells, stimulates macs and dendritic cells to produce inflammatory cytokines, causes early leukopenia, enhances glycolysis thus may lead to hypoglycemia.

Front 19

shock due to LPS or other septic symptoms can be fatal how? what does the activation of the coagulation pathway by cytokines lead to?

Back 19

extreme hypotension caused by vasodilation via NO from the cytokines leads to multiorgan failure due to hypoperfusion. disseminated intravascular coagulation

Front 20

describe the envelope of mycobacteria (includes TB)?

Back 20

related to gram pos, but do not stain pos, have outer layer of mycolic acid which is a lipid like, waxy substance. This provides resistance to detergents, many antibiotics and other antibacterial agents. It will stain acid fast

Front 21

describe the envelope of mycoplasmas.

Back 21

no cell wall, one membrane with sterols, again related to gram pos

Front 22

what does compliment do to gram neg bacs? gram pos bacs?

Back 22

lyses the bac. opsonizes but does not lyse

Front 23

what are the structure, function, and alternative names for the capsule?

Back 23

usually layer of polysaccharides (polypeptide in B. anthracis). It is an important virulence factor via antipahgocytic activity, adherance ability, and partial inhibition of complement mediated lysis.

Front 24

what organisms is vaccination with their capsular material effective?

Back 24

H. influenzae type b and S. pneumoniae.

Front 25

another name for the antigenic aspect of flagella is...?

Back 25

H antigen

Front 26

describe the structure, function, and uses of the pili.

Back 26

composed of protein subunits, cover entire cell surface, specialized sex pili transfer plasmids during conjugation. promote adherence to host or other bacteria. and they are antigenic.

Front 27

what kind of bacteria can produce endospores?

Back 27

some gram + bacteria

Front 28

endospores are only sensitive to what?

Back 28

steam (autoclave), glutaraldehyde, hypochlorite, and peracetic acid

Front 29

describe the structure of the endospore and the specefic function of the different levels of structure.

Back 29

the core contains the genome, protein synth machinery, and energy. Next is the spore wall which is made of peptidoglycan, then is the cortex which is concentric layers of peptidoglycan, then the spore coat which is keratin like and contains ample disulfide bonds, then the exosporum which is the remnant of the mother cell membranes. note that dipicolinic acid is found in all endospores and helps protect DNA

Front 30

the oxidase test detects what? what orgs does it help differentiate?

Back 30

detects the presence of cytochrome C oxidase and differentiates pseudomonads from enterobacterciae.