Micro Basics

Question 1

Gram positive

Answer 1

look blue with crystal violet stain

Question 2

Gram negative

Answer 2

look red from crystal violet stain and instead absorb safranin from the counterstain

Question 3

Gram positive layers

Answer 3

2 layers: inner cytoplasmic membrane, outer peptidoglycan layer thick with extensive AA cross-linking
outer cell wall with complex cross-linked proteoglycan, teichoic acid, polysaccharides, and other proteins

Question 4

Gram positive is missing…

Answer 4

NO endotoxin
NO periplasmic space
NO porin channel

Question 5

Gram positive high or low lipid content?

Answer 5

Low

Question 6

What kind of attacks are gram positive vulnerable to?

Answer 6

lysozyme and penicillin

Question 7

Gram negative layers

Answer 7

3
inner cytoplasmic membrane
thin peptidoglycan layer with minimal AA cross linking
outer membrane with LPS

Question 8

Gram negative high or low lipid content?

Answer 8

High

Question 9

What do gram negative organisms have that gram positive ones do not?

Answer 9

endotoxin-LPS
periplasmic space
porin proteins

Question 10

Gram negative LPS layers

Answer 10

outer: specific side chain (made of oligosaccharides) that are useful for Ags for the immune system to respond to
water soluble core polysaccharide
lipid A that is toxic to humans as the gram negative endotoxin; released as our immune system lyses the cells and allows it to be released

Question 11

What kind of attacks are gram negative organisms resistant to?

Answer 11

lysozyme and penicillin

opposite of gram positive which is vulnerable to these attacks

Question 12

Clinical relevance of the difference between gram +/-

Answer 12

gram + cell membranes have the ability to allow low molecular weight substances through like dyes and antibiotics, while the gram - does not, making them more resistant

Question 13

4 main shapes of bacteria

Answer 13

cocci
bacilli
spiral forms
pleomorphic

Question 14

Cocci

Answer 14

spherical

Question 15

Bacilli

Answer 15

Rods

short rods are coccobacilli

Question 16

Spiral forms

Answer 16

comma shaped, S-shaped, or spiral shaped

Question 17

Pleomorphic

Answer 17

lacking a distinct shape (like jello)

Question 18

7 classic gram positive bugs in humans

Answer 18

Streptococcus
Enterococcus
Staphylococcus
Bacillus
Clostridium
Corynebacterium
Listeria

Question 19

Gram positive cocci in humans

Answer 19

Form strips–>streptococcus, enterococcus

form clusters–>staphylococcus

Question 20

Gram positive rods in humans

Answer 20

produce spores–>bacillus, clostridium

no spores–>corynebacterium, listeria

Question 21

Gram negative cocci in humans

Answer 21

diplococcic
Neisseria
Moraxella

Question 22

Gram negative spiral shaped in humans

Answer 22

treponema
sorrelia
leptospira

Question 23

Other gram negatives in humans

Answer 23

rods or pleomorphic

Question 24

Mycobacteria

Answer 24

weakly gram +, stain better with acid fast

Question 25

Spirochetes

Answer 25

have a gram - cell wall, too small to be seen on light microscope, better with dark field have a few exposed membrane proteins and hidden internal periplasmic flagella

Question 26

Mycoplasma

Answer 26

no cell wall, only cell membrane so are neither gram - or +

Question 27

Bacterial DNA

Answer 27

circular and can send out small circles called plasmids

Question 28

Prokaryotic ribosomes

Answer 28

70S with a 50S and 30S subunit

Question 29

Eukaryotic ribosomes

Answer 29

80S

Question 30

Obligate aerobes

Answer 30

use all of the same O2 energy gaining mechanisms that humans use possess catalase, SOD, and peroxidase

Question 31

Facultative anaerobes

Answer 31

prefer to use O2 like humans, but can also go to fermentation if need be to live possess catalase and SOD

Question 32

Microaerophilic

Answer 32

use only fermentation and can only survive a little O2 with the help of SOD

Question 33

Obligate anaerobes

Answer 33

have no defense against O2

Question 34

Catalase

Answer 34

allows for H2O2 to be broken down to water and O2

Question 35

All staph related to Catalse

Answer 35

catalase positive

Question 36

All strep related to Catalase

Answer 36

catalase negative

Question 37

Gram positive facultative aerobes

Answer 37

bacillus cereus

Question 38

Gram positive facultative anaerobes

Answer 38

staph bacillus antracis cornyebacterium listeria

Question 39

Gram positive microaerophilic

Answer 39

enterococcus | strep (some are facultative)

Question 40

Gram positive obligate aerobes

Answer 40

clostridium | prefer puncture wounds

Question 41

Gram negative obligate aerobes

Answer 41

``` Neisseria pseudomonas bordetella legionella brucella ```

Question 42

Gram - facultative anaerobes

Answer 42

most other gram - rods

Question 43

Gram - microaerophilic

Answer 43

spirochetes-->treponema, borrelia, leptospira | campylobacter

Question 44

Gram - obligate anaerobes

Answer 44

bacteroides