Chapter 2/4: Bacterial Cell Walls Flashcards Preview

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Flashcards in Chapter 2/4: Bacterial Cell Walls Deck (37):
1

What are most bacterial cell walls composed of?

Peptidoglycan

2

Which two alternating molecules make up petidoglycan?

NAM, NAG

3

Which peptidoglycan subunit is cross-linked at adjacent layers by peptide bonds?

NAM

4

Which two amino acids are connected by a single peptide bond in peptidoglycan cross-linking?

DAP, D-Ala

5

Which two amino acids are connected by a pentaglycine interbridge in peptidoglycan-cross linking?

L-Lys, D-Ala

6

What type of bacteria use a single peptide bond in peptidoglycan cross-linking?

Gram negative

7

What type of bacteria use a pentaglycine interbridge in peptidoglycan cross-linking?

Gram positive

8

What molecule acts as a carrier for NAM in peptidoglycan synthesis?

UDP

9

What serves as a transport channel across the plasma membrane in peptidoglycan synthesis?

Bactoprenol

10

What is the name for the space between the plasma membrane and cell wall?

Periplasm

11

What protein can cleave the bond between NAM-NAG subunits in the peptidoglycan backbone?

Lysozyme

12

What type of structure forms in Gram positive cells after lysozyme treatment?

Protoplast

13

What type of structure forms in Gram negative cells after lysozyme treatment?

Spheroplast

14

What molecule can cleave the peptide interbridge cross-link in certain Staphylococcus species?

Lysostaphin

15

What type of antibiotics prevent transpeptidation?

Beta-lactam

16

What is produced in resistance to Beta-lactam antibiotics?

Beta-lactamases

17

What drug binds to Bactoprenol to prevent subunit synthesis and transport?

Bacitracin

18

What drug prevents NAM-NAG linkages from forming and transpeptidation?

Vancomycin

19

What are three types of Beta-lactam antibiotics?

Penicillin, Ampicillin, Cephalosporin

20

What types of major phenetic group divisions are based on cell wall chemistry differences?

Gram positive vs. Gram negative, Acid fast vs. non acid-fast

21

What type of bacteria lack a cell wall completely?

Mycoplasma sp.

22

What color are Gram-negative cells stained?

Pink

23

What color are Gram-positive cells stained?

Purple

24

What type of cell walls have a thick outer layer of peptidoglycan and a very narrow periplasmic space?

Gram-positive cell walls

25

What negatively charged molecules spear through the peptidoglycan layers in Gram-positive cell walls?

Teichoic acids

26

What function do Teichoic acids serve in Gram-positive cell walls?

Structure

27

What type of cell walls have a varying width periplasmic space and a thin layer of peptidoglycan?

Gram-negative cell walls

28

What type of cell walls have an additional outer membrane?

Gram-negative cell walls

29

What is the outer membrane composed of in Gram-negative cell walls?

Lipopolysaccharide (LPS)

30

What type of cell walls have a peptidoglycan layer with large pores?

Gram-positive cell walls

31

What proteins serve in transport in Gram-negative cells?

Porin, TonB

32

What type of rare transporters allow movement from the periplasm directly to the outside of the cell?

Autotransporters

33

What type of transporters shuttle materials from the cytoplasm to outside of cell in a single step?

Type III

34

What primary stain is used in a gram stain?

Crystal violet

35

What mordant is used in a gram stain to crystallize purple stain?

Gram's iodine

36

What decolorizer dissolves lipopolysaccharides and shrinks Gram-positive large pores in a gram stain?

95% ethanol

37

What counterstain enters only vacant cells in a gram stain?

Safranin