Review I -- Bacteria Growth

Question 1

What is Binary fission?

Answer 1

divides into 2

1 parent to 2 daughter sells

Question 2

What factors influence binary fission in bacteria (i.e. generation time)?

Answer 2

Influenced by: genetic make-up, environmental conditions

Question 3

What does exponential growth mean?

Answer 3

At a fast rate. 2 - 4 - 8 - 16 - 32 ect…..

Question 4

Know the following phases of the bacterial growth curve and characteristics about each phase (ex. What influences the rate of growth at each phase)?
1. Lag phase

Answer 4

A. Bacteria are adjusting to environment

B. Bacteria unable to adjust will not grow

C. Bacteria are metabolically active

D. Bacteria show NO signs of reproducing or dividing

Question 5

Know the following phases of the bacterial growth curve and characteristics about each phase (ex. What influences the rate of growth at each phase)?
2. Log phase

Answer 5

A. Bacteria cells are actively dividing (Divide at maximum rate)

B. Growth rate influenced by:

        1. Physical/Chemical environment
        2. Genetic make-up

C. Bacteria are at metabolic peak

D. Bacteria are most susceptible to antibiotics and antiseptics

Question 6

Know the following phases of the bacterial growth curve and characteristics about each phase (ex. What influences the rate of growth at each phase)?
3. Stationary phase

Answer 6

A. No increase in Population size

           1. Death rate = Reproduction rate
           2. Every cell in the population stops dividing                                  but none die

B. Bacteria cell switch to lowest metabolic rate

C. Cells tend to be less susceptible to antibiotics

D. Spore formers form endospores as a protective mechanism

E. If growth conditions become favorable again, cells could return to Log Phase of growth

Question 7

Know the following phases of the bacterial growth curve and characteristics about each phase (ex. What influences the rate of growth at each phase)?
4. Death/Decline phase

Answer 7

A. Cell death occurs at an exponential rate

B. Death rate is at maximum rate

Question 8

What are the requirements for Microbial growth?

Answer 8

1

Question 9

What is the difference between the following: photoautotroph, chemoautotroph, photoheterotroph, and chemoheterotroph?

Answer 9

1

Question 10

photoautotroph

Answer 10

Energy source: sunlight
Carbon source: Carbon Dioxide
Cyanobacteria pigmented blue green

Question 11

chemoautotroph

Answer 11

Energy Source: Inorganic molecules like sulfur or nitrogen

Carbon Source: Carbon dioxide

Question 12

photoheterotroph

Answer 12

Energy Source: Sunlight

Carbon Source: Organic molecules like protein, sugar

Question 13

chemoheterotroph

Answer 13

Energy Source: Organic molecules
Carbon Source: Organic molecules
Includes most bacteria including pathogens(disease causing) and saprobes(decomposer)

Question 14

What is difference between a saprobe and parasite?

Answer 14

saprobe is a decomposer

parasite is a disease causing

Question 15

. What are the four main temperature growth groups? (psychrophiles, etc…)

Answer 15

Psychrophiles,Mesophiles,Thermophiles,Extreme Thermophiles:

Question 16

Know the five main categories of oxygen requirement for bacteria growth.

Answer 16

Obligate Aerobe,Obligate Anaerobe,Necrotic tissue,Aerotolerant Organisms,Facultative anaerobe

Question 17

What is the effect of pH on bacteria growth?

Answer 17

6-8 tolerated

Question 18

What is the pH scale?

Answer 18

0 pH 7 pH = acid
7 pH  14pH = base(alkaline)
7 pH is neutral

Question 19

What pH does most bacteria prefer?

Answer 19

Most bacteria prefer pH = 7
pH range for most bacteria is 6 – 8
Exceptions: Helicobacter pylori survives pH = 2