HW 4-6

Question 1

If you want to isolate a pure culture of a bacterium, it is necessary to use what type of growth medium?
1)Solid
2)Complex
3)Defined
4)Liquid

Answer 1

Solid

Question 2

A growth medium containing an antibiotic would be considered a:
1)Complex medium
2)Differential Medium
3)Selective Medium
4)Defined Medium

Answer 2

Selective Medium

Question 3

Direct Count

Answer 3

Measuring population size by counting under a microscope

Question 4

Viable count

Answer 4

Measuring population size by counting colonies on a plate

Question 5

Optical Density

Answer 5

Measuring population size by measuring light scattering

Question 6

Substances added to a culture to keep the pH constant are known as ____

Answer 6

buffers

Question 7

The multiprotein structure that drives septum formation and constriction is called the ___

Answer 7

Divisome

Question 8

Describe how the Min proteins determine the location of septum formation in E.coli.

Answer 8

The Min proteins constantly oscillate from one cell pole to the other. They inhibit divisome formation, and so the divisome forms at the location of lowest average Min protein concentration over time.

Question 9

What is the appearance of bacterial cells in the genus Streptococcus?
1)Individual cocci
2)Groups of 4 or 8 cocci
3)Chains of cocci
4)Individual bacilli
5)Pairs of bacilli
6)Chains of bacilli

Answer 9

Chains of cocci

Question 10

In archaeal lipids, hydrophobic carbon chains are attached to glycerol via:
1)Ether bonds
2)Hydrogen bonds
3)Lipoproteins
4)Ester bonds
5)Bactoprenol

Answer 10

Ether bonds

Question 11

Lipoploysaccharide found in:

Answer 11

Outer membrane

Question 12

Bactoprenol found in:

Answer 12

Cytoplasmic membrane

Question 13

N-Acetylmuramic acid found in:

Answer 13

Peptidoglycan

Question 14

Phytanyl found in:

Answer 14

Cytoplasmic membrane

Question 15

The enzyme found in human secretions that can digest peptidoglycan is called_____

Answer 15

lysozyme

Question 16

A rotating filamentous structure on a bacterial cell surface is called a _____

Answer 16

flagella

Question 17

What membrane is the proton motive force built across?
How is the location of the high proton concentration different between Gram-negative and Gram-positive cells?

Answer 17

The proton motive force is across the cytoplasmic membrane. In Gram-negative species,, the high proton concentration is maintained in the periplasm, inside the outer membrane. IN Gram-positive species, there is no outer membrane to maintain the protons; Teichoic acids assist in maintain the proton gradient.