Bacteria Structure and Function 1

Question 1

Which of the following is characteristic of bacteria: introns, nucleus, membrane-bound organelles, cell wall, mitosis

Answer 1

Only a cell wall. Bacteria have no introns, no nucleus or other membrane-bound compartments (only a nucleoid region), and reproduce by binary fission not mitosis

Question 2

Bacteria reproduction occurs by what process?

Answer 2

Binary fission

Question 3

What is a bacterial cell wall made of?

Answer 3

Peptidoglycan

Question 4

Is the bacterial ribosome 70S or 80S?

Answer 4

70S - eukaryotes have 80S ribosomes. (makes the bact. ribosome a good drug target)

Question 5

Staph, Strep, and Neisseria bacteria have what type of shape?

Answer 5

Coccus / round

Question 6

E. coli, Vibrio, and Salmonella have what type of shape?

Answer 6

Bacillus / rod (vibrio is a curved rod)

Question 7

Corynebacter, Fusobacter, and Pseudomonas have what type of shape?

Answer 7

Bacillus / rod

Question 8

Borrelia and Treponema have what type of shape?

Answer 8

Spirochete / corkscrew

Question 9

Treponema is very narrow and therefore requires what type of technology to view it?

Answer 9

A darkfield

Question 10

In Gram staining, bacteria are fixed to a slide with heat and then what 4 chemicals are applied (in order)?

Answer 10

Crystal violet (stain) - Iodine (fix) - Alcohol (wash) - Safrinin (counterstain)

Question 11

Describe the membrane and peptidoglycan layers of a Gram (-) bacterium cell wall

Answer 11

2 membranes (inner and outer) + 1 layer of peptidoglycan in between

Question 12

Describe the membrane and peptidoglycan layers of a Gram (+) bacterium cell wall

Answer 12

1 membrane (inner) + 3 layers of peptidoglycan outside

Question 13

What is the most commonly ordered bacterial lab test?

Answer 13

Gram stain

Question 14

Gram (-) diplococci in a cervical smear are indicative of what disease?

Answer 14

N. gonorrhea

Question 15

Which bacteria have LPS/LOS/endotoxin in their plasma membranes: Gram (+), Gram (-), or Acid-Fast?

Answer 15

Gram (-)

Question 16

Which bacteria have more frequent genetic exchanges: Gram (+) or Gram (-)?

Answer 16

Gram (-)

Question 17

Mycobacterium tuberculosis is an example of bacteria with cell walls that are neither Gram (+) nor Gram (-). How is the stain for these mycobacteria described?

Answer 17

Acid-Fast

Question 18

Penicillin, cephalosporins, and vancomycin all inhibit synthesis of what bacterial molecule (Lysozymes also cleave this molecule)?

Answer 18

Peptidoglycan

Question 19

Which bacteria have porins: Gram (+), Gram (-), or Acid-Fast?

Answer 19

Gram (-) and Acid-Fast both have porins

Question 20

What is the less toxic, Gram (+) equivalent of the LPS found in Gram (-) bacteria?

Answer 20

Teichoic Acid. (It can also cause septic shock, but less commonly than LPS)

Question 21

What is the name of the molecule that can form either slime layers/biofilms or capsules around a bacteria?

Answer 21

Glycocalyx

Question 22

What feature of a bacterium aids in attachment and in biofilm formation?

Answer 22

A slime layer

Question 23

What feature of a bacterium aids in attachment and resistance to phagocytosis?

Answer 23

A capsule

Question 24

What feature of a bacterium which aids in attachment is also useful for serologic testing and as a vaccine target?

Answer 24

A capsule

Question 25

Which of the following bacterial structures are useful for attachment: flagellae or pili/fimbrae?

Answer 25

Pili/fimbrae

Question 26

Which of the following bacterial structures are useful for movement: flagellae or pili/fimbrae?

Answer 26

Both

Question 27

Which pili are more complex and have more variation: those of Gram (-) or Gram (+) bacteria?

Answer 27

Gram (-) bacteria (come in many different types)

Question 28

How many bacteria can fit inside a mammalian cell: 10s, 100s, or 1000s?

Answer 28

Hundreds

Question 29

Which kind of bacteria have thicker cell walls: Gram (+) or Gram (-)?

Answer 29

Gram (+): they have 3 peptidoglycan layers

Question 30

In Acid-Fast bacteria, what molecule outside the peptidoglycan layer resists both the crystal violet stain and the safrinin counterstain?

Answer 30

Mycolic Acid

Question 31

Name the compounds in Gram (+) and Gram (-) bacteria that can cause septic shock:

Answer 31

Gram (+): Teichoic Acid; Gram (-): LPS

Question 32

In Gram (-) bacteria, which type of pili are responsible for attachment?

Answer 32

Type 1

Question 33

In Gram (-) bacteria, which type of pili are responsible for propulsion?

Answer 33

Type 4

Question 34

In Gram (-) bacteria, which 2 types of pili are responsible for secretion?

Answer 34

Types 3 and 4