Basic Bacteriology: Bacterial Structures and Taxonomy Flashcards Preview

First Aid: Microbiology Cards > Basic Bacteriology: Bacterial Structures and Taxonomy > Flashcards

Flashcards in Basic Bacteriology: Bacterial Structures and Taxonomy Deck (26):
1

What is the function and chemical composition of peptidoglycan?

Function: Rigid support, protect against osmotic pressure.

Composition: Sugar backbone with peptide side chains cross-linked by transpeptidase

2

What is the function and chemical composition of the cell wall/cell membrane of gram positive bacteria?

Function: Major surface antigen

Composition: Peptidoglycan for support. Lipoteichoic acid induces TNF and IL-1.

3

What is the function and chemical composition of the outer membrane of gram negative bacteria?

Function: Site of endotoxin (lipopolysaccharide [LPS]); major surface antigen

Composition: Lipin A induces TNF and IL-1. O polysaccharide is the antigen.

4

What is the function and chemical composition of the bacterial plasma membrane?

Function: Site of oxidative and transport enzymes

Composition: Phospholipid bilayer

5

What is the function and chemical composition of bacterial ribosomes?

Function: Protein synthesis

Composition: 50S and 30S subunits

6

What is the function and chemical composition of bacterial periplasm?

Function: Space between cytoplasmic membrane and outer membrane in gram-negative bacteria.

Composition: Contains hydrolytic enzymes, including beta-lactamases.

7

What is the function and chemical composition of bacterial capsules?

Function: Protects against phagocytosis

Composition: Polysaccharide (except Bacillus anthracis, which contains D-glutamate).

8

What is the function and chemical composition of bacterial pilus/fimbria?

Function: Mediate adherence of bacteria to cell surface; sex pilus forms attachment between 2 bacteria during conjugation

Composition: Glycoprotein

9

What is the function and chemical composition of a bacterial flagellum?

Function: Motility

Composition: Protein

10

What is the function and chemical composition of bacterial spores?

Function: Resistant to dehydration, heat, and chemicals

Composition: Keratin-like coat, dipicolinic acid, peptidoglycan.

11

What is the function and chemical composition of bacterial plasmids?

Function: Contains genes for antibitoic resistance, enzymes, and toxins

Composition: DNA

12

What is the function and chemical composition of bacterial glycocalyx?

Function: Mediate adherence to surfaces, especially foreign surfaces (indwelling catheter)

Composition: Polysaccharide

13

What cell wall structures are shared between gram-negative and gram-positive organisms?

Flagellum, Pilus, Capsule, Peptidoglycan, and Cytoplasmic Membrane.

(See figure page 120)

14

What cell wall structures are unique to gram positive organisms?

Lipoteichoic acid

(See figure page 120)

15

What cell wall structures are unique to gram-negative bacteria?

Endotoxin/LPS

Periplasm

(See figure page 120)

16

Name the genera of gram-positive and gram-negative cocci.

Gram positive: Staphylococcus, Streptococcus

Gram negative: Neisseria

17

Name the genera of gram-positive rods.

Clostridium

Corynebacterium

Bacillus

Listeria

Mycobacterium (acid fast)

Gardnerella (gram variable)

18

Name the genera of enteric gram-negative rods (bacilli).

(There's lots!)

E. coli, Shigella, Salmonella, Yersinia, Klebsiella, Proteus, Enterobacter, Serratia, Vibrio, Campylobacter, Helicobacter, Pseudomonas, Bacteroides

19

Name the genera of gram-negative respiratory rods.

Haemophilus (pleomorphic morphology)

Legionella (silver stain)

Bordetella

20

Name the genera of zoonotic gram-negative rods.

Francisella

Brucella

Pasteurella

Bartonella

21

Name the genera of branching, filamentous bacteria.
Are they gram-positive or gram-negative?

Gram-positive.

Actinomyces

Nocardia (weakly acid fast)

22

What are the genera of highly pleomorphic bacteria?

If you see a pleomorphic bacteria, is it likely gram positive or gram negative?

Gram negative!

Rickettsiae (Giemsa stain)

Chlamydiae (Giemsa stain)

 

(Haemophilus is also pleomorphic - or a coccobacilli, and it's also gram negative.)

23

What are the genera of spiral bacteria?

Do these tend to be gram negative or gram positive?

Spiral = spirochetes. Tend to stain gram-negative.

Borrelia (Giemsa stain)

Leptospira

Treponema

24

What genus of bacteria has no cell wall?

Mycoplasma (does not gram stain)

25

What is unique about mycoplasma plasma membranes?

No cell wall

Contain sterols

26

What is unique about mycobacterial cell membranes/walls?

Contain mycolic acid.

High lipid content