BACTERIAL GROWTH REQUIREMENT

Question 1

involves an orderly and organized increase in the sum of all components of the
organism which may entail replication of all cellular structures, organelles, and
components.

Answer 1

Growth

Question 2

concerned with the increase in number of cells and not increase in the size of the organism

Answer 2

• Microbial growth

Question 3

The process by which organisms divide and reproduce

Answer 3

BINARY FISSION

Question 4

Time required for a cell to divide and its population to

double

Answer 4

GENERATION TIME

Question 5

Illustrates the phases in the growth of the population of bacteria when they are grown in a culture of fixed volume. It reflects the different stages in the growth of a bacterium

Answer 5

BACTERIAL GROWTH CURVE

Question 6

• Bacteria are still adjusting to their environment
  • Bacteria absorb nutrients, synthesize enzymes, and prepare for cell division.
  • Cells grow in size but not in number

Answer 6

LAG PHASE

Question 7

*Exponential or logarithmic phase
• Rapid binary fission
• Number of cells grow exponentially
• Very susceptible to Gram Staining and cell wall inhibitors

Answer 7

LOG PHASE

Question 8

• culture is at its greatest population density.
  • Number of cells produced= number of cells dying
  • nutrients in the liquid medium are used up
  • concentration of toxic waste products from the metabolizing bacteria build up

Answer 8

STATIONARY PHASE

Question 9

*aka logarithmic decline phase Accumulation of toxic metabolites and autolytic enzymes
• culture may die completely, or a few microorganisms or may continue to survive for months
• formation of spores
• Morphologic changes occur (Bacteria assume different shapes)

Answer 9

DEATH PHASE

Question 10

give the BACTERIAL GROWTH REQUIREMENTS (physical)

Answer 10

1. water/moisture
2. Temperature
3. pH
4. Osmotic pressure
5. Oxygen

Question 11

why is water/moisture a physical requirement for bacterial growth?

Answer 11

The bacterial cell is composed mainly of water. All living organisms require water to carry out their normal metabolic processes, and most will die in environments containing too little moisture.

Question 12

live in the refrigerator

Answer 12

(0-20 oC) Psychrophiles

Question 13

very pathogenic

Answer 13

.Mesophiles (21-45 oC)

Question 14

 freeze at body temperature

Answer 14

Thermophiles (46 oC and higher)

Question 15

bacterial physical requirement – pH 8.4 – 9.0

Answer 15

Alkalophiles

Question 16

bac growth req– pH 6.5 – 7.5

Answer 16

Neutrophiles

Question 17

Acidophiles

Answer 17

– pH less than 6

Question 18

osmotic pressure- – require very high salt concentration for growth

Answer 18

.Extreme halophiles

Question 19

OSMOTIC PRESSURE- require very high salt concentration for growth.

Answer 19

Extreme halophiles

Question 20

require enough salt concentration for growth

Answer 20

Obligate halophiles

Question 21

– do not require high salt concentration but able to grow at salt concentrations up to 2%.

Answer 21

Facultative halophiles

Question 22

Only aerobic growth; oxygen required. high concentration of oxygen (bacteria all at the top)

Answer 22

OBLIGATE AEROBES

Question 23

growth is best where most oxygen is present, but occurs throughout tube. Growth is greater in presence of oxygen

Answer 23

FACULTATIVE ANAEROBES

Question 24

only anaerobic growth, ceases in presence of oxygen. growth where there is no oxygen

Answer 24

OBLIGATE ANAEROBES

Question 25

Only anaerobic growth, continues in presence of oxygen, occurs evenly, oxygen has no effect

Answer 25

AEROTOLERANT ANAEROBES

Question 26

only aerobic growth; oxygen required in low concentration, growth occurs where a low concentration of oxygen has diffused into medium (BACTERIA IN THE MIDDLE)

Answer 26

MICROAEROPHILES

Question 27

A FACULTATICE ANAEROBE WITH NO CELL WALL

Answer 27

MYCOPLASMA

Question 28

WHAT ARE THE CHEMICAL REQUIREMENTS?

Answer 28

1. carbon 2. nitrogen, sulfur, phosphorus 3. inorganic ions 4. growth factors

Question 29

organisms that use lift as an energy source

Answer 29

PHOTOTROPHS

Question 30

organisms that use chemicals as an energy source

Answer 30

CHEMOTROPHS

Question 31

organisms that use CO2 as a carbon source

Answer 31

AUTOTROPHS

Question 32

e.g., algae, plants, some photosynthetic bacteria including cyano bacteria

Answer 32

PHOTOAUTOTROPHS

Question 33

e.g, some bacteria

Answer 33

CHEMOAUTOTROPHS

Question 34

organisms that use organic compounds other than COc as a carbon source

Answer 34

HETEROTROPHS

Question 35

e.g, some photosynthetic bacteria

Answer 35

PHOTOHETEROTROPHS

Question 36

e.g, protozoa, fungi, animals, most bacteria

Answer 36

CHEMOHETEROTROPHS

Question 37

necessary for synthesis of proteins and nucleic acids

Answer 37

Nitrogen, Sulfur, Phosphorus

Question 38

what are the inorganic ions?

Answer 38

magnesium potassium calcium iron

Question 39

stabilizes ribosomes, cell membranes, and nucleic acids; also serves as co-factor in the activity of enzymes

Answer 39

MAGNESIUM (Mg)

Question 40

for normal functioning and integrity of ribosomes and enzyme activities

Answer 40

POTASSIUM (K)

Question 41

important component of gram-positive bacterial cell wall and contributes to the resistance of bacterial endospores

Answer 41

CALCIUM (Ca)

Question 42

component of cytochrome, a component of the electron transport chain and co-factor for enzymatic activities

Answer 42

IRON (Fe)

Question 43

Essential to promote the growth and development of the bacterial cell. These include Vitamin B Complex and amino acids.

Answer 43

Growth Factors

Question 44

bacteria with the fastest generation time

Answer 44

BACILLUS THERMOPHILUS (1.3MINS)

Question 45

Bacteria with the longest generation time

Answer 45

TREPONEMA PALLIDUM (1980mins)