Lecture 4:

Question 1

What is the capsule made of?

Answer 1

Glycocalyx

Question 2

What is the slime layer made of?

Answer 2

Glycocalyx

Question 3

Do bacteria demonstrate learning behavior?

Answer 3

Yes!

Question 4

How much of our cells are actually human?

Answer 4

10%

Question 5

How much of the genetic material in our body is human?

Answer 5

1%

Question 6

What does the new view of bacterial biology state?

Answer 6

Bacteria are:
• Highly ordered and dynamic
• Capable of polarizing and differentiation into cell types
• Signal each other to coordinate multicellular actions
• Exhibit learning behaviour – anticipate changes in their environment
(Pavlovian conditioning)

Question 7

Is it possible to produce synthetic microorganisms?

Answer 7

Yes.

Question 8

What is the cell wall of a bacterial cell mostly made of?

Answer 8

Peptidoglycan

Question 9

On average, how many years of life does antibiotics add to a person?

Answer 9

20!

Question 10

What is the function of bacterial cell walls?

Answer 10

1. Rigid macromolecular layer that provides strength to cell

2. Protect cells from osmotic lysis and confers cell shape

Question 11

How does antibiotics work?

Answer 11

It targets the peptidoglycan cell wall, and the cell explodes from osmotic pressure.

Question 12

What is transpeptidase?

Answer 12

The enzyme that cross links the peptidoglycan chains to form rigid cell walls.

Question 13

What two types of cells does a gram test test for?

Answer 13

Gram positive and gram negative.

Question 14

What type of cell has a very thick layer of peptidoglycan?

Answer 14

Gram positive (dye remains in the gram test).

Question 15

What is a gram negative cell?

Answer 15

A type of cell that has a thin layer of peptidoglycan between two membranes.

Question 16

Do bacteria operate in a coordinated or random fashion?

Answer 16

Coordinated.

Question 17

What are the three parts that make up the Flagella?

Answer 17

The long filament, the hook and the basal body.

Question 18

What is the long filament of a flagella?

Answer 18

The part that extends out and operates like the blades of a rotor.

Question 19

What is the hook of a flagella?

Answer 19

A curved section which connects the filament to the cell wall.

Question 20

What is the basal body of a flagella?

Answer 20

The ‘gears’, for coordinating speed and rotation.

Question 21

As bacteria are too small to sense spatial gradients, how do they navigate?

Answer 21

They ‘tumble’ and ‘run’, moving forward, sensing concentration (using chemoreceptors), comparing and moving forward again.

Question 22

What is the main purpose of fimbrae?

Answer 22

Adhesion.

Question 23

What are fimbrae, and what is another name for them?

Answer 23

They are ‘hairs’ on the surface of bacterial cells with adhesins on the outer ends. These adhesins bind to specific receptors.

Question 24

What’s the difference between capsules and slime layers?

Answer 24

Capsules are well organised around the cell, whereas slime layers make a random mesh around the cell.

Question 25

What is an example of asymmetric cell division?

Answer 25

Bacterial endospores

Question 26

What is the advantage of a bacterial endospore?

Answer 26

They are resistant to heat, harsh chemicals, etc. and can remain dormant for a long time, until conditions are ideal.

Question 27

What are the protective layers of an endospore?

Answer 27

Exosporium, spore coat, core wall, cortex, and then the DNA.

Question 28

True or False:

“Bacterial endospores have a very high water content”

Answer 28

FALSE. Bacterial endospores have low water content.