Bacteria anatomy

Question 1

Why is it important to study bacterial structures?

Answer 1

• Identification
• Determine pathogenicity and pathogenesis
• Targets for control

Question 2

3 basic shapes of bacteria?

Answer 2

• Spherical (coccus)
• Rods (bacillus)
• Spirals or spirochets

Question 3

What is a monomorphic shape?

Answer 3

Uniform shape and size

Question 4

What is pleomorphic

Answer 4

Variable shape

Question 5

What are three broad categories of bacterial structures?

Answer 5

1. Cell envelope (cytoplasmic membrane and cell wall)
2. Cytoplasmic structures
3. Surface structures

Question 6

What are bacterial cytoplasmic membranes made of?

Answer 6

Phospholipids and proteins but no sterols

Question 7

What is one bacteria that does have sterols in their cytoplasmic membrane?

Answer 7

Mycoplasma

Question 8

What is the function of cytoplasmic membrane?

Answer 8

• Selective barrier
• Contains enzymes
• Target for antibiotics and disinfectants

Question 9

What is the purpose of the cell wall

Answer 9

• Complex and rigid
• Protects interior of the cell
• Contributes to virulence
• Determines gram stain

Question 10

What are the steps of the Gram stain?

Answer 10

1. Crystal violet
2. Iodine (mordant)
3. Alcohol (decolorizing agent)
4. Safranin (counter stain)

Question 11

What color is gram positive?

Answer 11

Purple

Question 12

What color is gram negative?

Answer 12

Pink, colorless until you use the counter stain

Question 13

What is the macromolecule cell wall are made of?

Answer 13

Peptidoglycan

Question 14

What is the target for penicillin?

Answer 14

The cross linkage between tetrapeptides of peptidoglycans

Question 15

What is the periplasm?

Answer 15

Space between peptidoglycan and cytoplasmic membrane

Question 16

What is teichoic acid?

Answer 16

Polymer of glycerol or ribitol with phasphate. Only found in Gram +

Question 17

What are the classes of teichoic acid?

Answer 17

• Lipoteichoic acid

- Cell wall teichoic acid

Question 18

What is the function of teichoic acid

Answer 18

Transport cations

Question 19

What is the biggest difference in cell envelope of Gram-

Answer 19

Very tin peptidoglycan wall

Question 20

What is the outer membrane of gram - made of?

Answer 20

Lipopolysaccharide and protein

Question 21

What is the cell envelope consist of in gram -

Answer 21

Cytoplasmic membrane (phospholipid), Peptidoglycan (thin), Outer membrane (phospholipid and lipid a)

Question 22

What is lipopolysaccharide?

Answer 22

Endotoxin. Found in gram -. Main component is lipid A

Question 23

What is in the cell wall of mycobacterium?

Answer 23

No peptidoglycan. Contains waxy lipid coat of mycolic acid

Question 24

How can you stain mycobacterium?

Answer 24

Acid fast staining

Question 25

What is extrachromosomal DNA?

Answer 25

Plasmid

Question 26

Do bacteria have nuclear membranes?

Answer 26

No

Question 27

What type of DNA do bacteria have?

Answer 27

Circular dsDNA

Question 28

What type of ribosome do bacteria have?

Answer 28

70S. 16S rRNA 1500 NT

Question 29

What are mesosomes?

Answer 29

Only found in Gram -. Folds of cell membrane in cytoplasm used for cell division

Question 30

What are inclusions or storage granules?

Answer 30

Reserve materials stored in cytoplasm

Question 31

What genes are found in plasmids?

Answer 31

Selective advantages to the cells not for growth or division

Question 32

What is curing?

Answer 32

Elimination of plasmids either spontaneously or from treatment

Question 33

What are spores?

Answer 33

Consists of thick spore coat and resistant to most things. Ensures that the DNA inside survives

Question 34

What are actin-like proteins?

Answer 34

Cytoskeletons that give the cell its shape. Major ones is MreB in rods and spirals

Question 35

What are the types of cell surface structures?

Answer 35

Capsule or slime. Most are polysaccharide

Question 36

How do you stain capsule?

Answer 36

Negative stain. Stain everything but the capsule

Question 37

What is the function of capsules?

Answer 37

- Protection - Nutrition - Antigenic determinant (K antigen) - Mediates attachment

Question 38

What is the biofilm

Answer 38

Group of bacterial cells embedded in a common matrix of the capsular polysaccharide

Question 39

What is a flagella?

Answer 39

Originate from cytoplasmic membrane made from flagellin. Used for movement. Antigenic (H antigen)

Question 40

What are pili or fimbriae?

Answer 40

Made from protein pilin and mediate attachment to cells. Sex pilus is used in conjugation (Transfer of DNA)