Lecture 3

Question 1

Chromosome

Answer 1

Double Stranded
super coiled
All bacteria

Question 2

Plasmids

Answer 2

Some bacteria
Separate from the chromosome
Accessory genes to help adapt

Question 3

Mutation

Answer 3

Physical change in DNA = mRNA = change in protein

Spontaneous
Induced
Slow

Question 4

Conjugation (bacterial mating)

Answer 4

Transfer of plasmid by sex pili

Can retransfer so all will have it

Question 5

Binary Fission

Answer 5

1 cell => two Identical daughter cells

1 BF = Generation time (G)(doubles after every generation)

Species and environment dependent

Growth is the number of cells in the population

Question 6

One colony

Answer 6

One bacterial cell in the original suspension

CFU = Colony forming unit

Question 7

Requirement for Growth creates:

Answer 7

1. Grow bacteria in the lab

2. ability to analyse growth properties allowing identification of species

Question 8

Nutrients (GR)

Answer 8

Generate energy breaking down organic compounds

End products vary

Question 9

Water

Answer 9

essential requirement for bacterial growth

Solvent in which nutrients and enzymes are dissolved

Cannot grow without water but can survive dry conditions via spores

Question 10

pH (acid/alkali)

Answer 10

Neutral pH (7) is optimal

Some can grow at extremes

Question 11

Temperature Requirements

Answer 11

Grows over range (stops outside min/max range)

Optimum temp = one temp

Question 12

Psychrophiles

Answer 12

10 degrees

Food spoilage

Question 13

Mesophiles

Answer 13

37 degrees
Bacterial species (Humans)

Question 14

Thermophiles

Answer 14

70 degrees

Question 15

Extreme thermophiles

Answer 15

80 degrees and above

Question 16

Significance of Growth Temp

Answer 16

1. Food preservation:
   mesophiles do not grow not grow at low temp
   fridge temp prevent/slow growth
2. In Disease:
   Bacteria infect body sites

Question 17

significance of oxygen Requirements

Answer 17

body sites (muscles vs body)

Lab growth

Question 18

Aerobes

Answer 18

Need oxygen

Question 19

Anaerobes

Answer 19

Killed by oxygen

Question 20

Facultative anaerobes

Answer 20

Grow best if oxygen is present but can grow without