Exam 2

Question 1

Our model organism, E. coli, is which of the following:

Answer 1

Chemoorganotroph

Question 2

Peptidoglycan synthesis occurs where within the cell?

• cytoplasm
• cell membrane
• cell wall
• cytoplasm and cell membrane
• cytoplasm and cell wall
• all of the above

Answer 2

ALL of the above

Question 3

How does penicillin inhibit cell division?

Answer 3

Penicillin mimics the pentapeptide and covalently binds transpeptidase preventing the addition of peptidoglycan

Question 4

What is the structure of peptidoglycan monomers?

Answer 4

N-acteylglucosamine -> N-acteylmuramic acid -> pentapeptide crosslinker

Question 5

What is the condensed chromosome of a bacterium called?

Answer 5

Nucleoid

Question 6

Which of the following is an accumulation of extracellular material visible by microscopy?

Answer 6

capsule

Question 7

The rfa genes are involved in the synthesis of what molecule?

Answer 7

Lipopolysaccharide

Question 8

What microbial product is important for biofilm formation?

Answer 8

Slime Layer

Question 9

Which of the following best describes a bacterium’s movement?

Answer 9

Zig-Zag or circular random walk

Question 10

What type of export pathway is used to form the flagella filament?

Answer 10

Type III

Question 11

Which of the following is NOT a component of the bacterial flagella/chemotaxis?

Answer 11

Axoneme

Question 12

In E. coli, smooth directional swimming is associated with…

Answer 12

CCW flagellar rotation

Question 13

How do bacteria know when to change direction?

Answer 13

Stimulus of MCPs

Question 14

Superoxide dismutase are enzymes that dissipates superoxide to hydrogen peroxide and oxygen and are present in aerobic organisms.

Answer 14

True

Question 15

Which of the following secretion systems autotransport their cargo.

Answer 15

Type V

Question 16

Which of the following statement is true for Aerobic bacteria:

Answer 16

oxygen serves as the terminal electron acceptor

Question 17

Following is NOT true for Mesophilic bacteria

Answer 17

Maximum temperature at which bacterial can grow is >80 °C

Question 18

Which of the following transport mechanisms does not utilize energy?

Answer 18

Facilitated Diffusion

Question 19

Which of the following transport mechanisms modifies the transported material?

Answer 19

Group Transport

Question 20

The F0-F1 ATPase is an example of what type of transporter?

Answer 20

Ion driven

Question 21

Catalase are the enzymes:

Answer 21

All the statements are true

Question 22

How do Gram-positive bacteria secrete material?

Answer 22

Sec Pathway

Question 23

Clostridium tetani and botulism neurotoxin (BoNT) of Clostridium botulinum both are A-B toxin composed of heavy chain (B subunit) and light chain (A-subunit). Both TeNT and BoNT inhibit neuroexocytosis.

Answer 23

True

Question 24

Which of the following is not an example of Neurotoxin

Answer 24

Cholera toxin

Question 25

A-B toxins act as autotransporters. What class of toxin are these?

Answer 25

Exotoxins

Question 26

Which of the following is True about injected Toxins

Answer 26

They are secreted directly into the host cytoplasm by Type II and VI systems

Question 27

Which is an incorrect statement about Toxins

Answer 27

toxins are beneficial for the host

Question 28

Which of the below-mentioned statements are not correct about Cholera Toxin.

Answer 28

It increases absorption of Na+

Question 29

Bacteria use quorom sensing for what purpose?

Answer 29

To communicate with other bacteria in the area to work together

Question 30

Pore forming Toxins secreted by bacteria kills the host cell by:

Answer 30

by forming pores in the cell membranes

Question 31

Which of the following is NOT true about Anthrax toxin from Bacillus anthracis

Answer 31

It is an endotoxin

Question 32

Which of the following statements are true about Gliding Motility

Answer 32

All are true (select all) | except Type IV Pilli

Question 33

The growth of aerotolerant organisms is frequently enhanced by culture on media containing blood or other natural materials but contain catalase or peroxidase

Answer 33

True

Question 34

Complete LPS molecule is made up of

Answer 34

``` o-antigen core polysaccharide disaccharide diphosphate fatty acids (a, b, c and d) ```

Question 35

Select TRUE statements about Gram-Negative Bacteria

Answer 35

outer cell membrane LPS represent one of the most important features of gram-negative cells presence of LPS causes septic shock (a, b, c)

Question 36

Teichoic and Lipoteichoic acids are found in Gram-Negative bacteria

Answer 36

False

Question 37

Capsule does not have well-defined boundaries and is not visible by Microscopy

Answer 37

False

Question 38

Swarming Motility is a

Answer 38

rapid and coordinated movement of a bacterial population across a solid or semi-solid surface Coordinated quorum sensing Involves periodic morphological changes at 1-2 hr intervals Swarming motility are produced from relatively short and sparsely flagellated cells (ALL of the above)