LESSON 9: BACTERIAL GROWTH

Question 1

-refers to the increase in number of cells not the size of cells.

Answer 1

MICROBIAL GROWTH

Question 2

-bacteria undergo asexual division to produce 2 daughter cell genitically identical to the parent cell.

Answer 2

BINARY FISSION

Question 3

-the Z-ring is mainly composed of this polymers assemble in the middle of the cell.

Answer 3

FtsZ POLYMERS

Question 4

-it’s the first step of bacterial cytokines.

Answer 4

Z-RING

Question 5

-time required for a bacterium to give rise to 2 daughter cells under optimum conditions.

Answer 5

GENERATION TIME

Question 6

what is generation time o e.coli ?

Answer 6

20min, 7 hours can undergo 20 generations

Question 7

-bacterial counting can be measured in terms of?

Answer 7

1. CELL CONCENTRATION
2. BIOMASS CONCENTRATION

Question 8

-it’s a number of viable cell per unit volume

Answer 8

CELL CONCENTRATION

Question 9

-dry weight of cell per unit volume.

Answer 9

BIOMASS CONCENTRATION

Question 10

-it denotes the total number of bacteria whether they are living or deade.

Answer 10

TOTAL COUNT

Question 11

-total number of living or viable bacteria

Answer 11

VIABLE COUNT

Question 12

-viable count can be obtained by 2 method:

Answer 12

1. DILUTION METHOD
2. PLATING METHOD

Question 13

-series of sequential dilutions used to reduce a dense
culture of cells to a more usable concentrations.

Answer 13

DILUTION METHOD

Question 14

-number of colonies that grow after a suitable incubation time.

Answer 14

PLATING METHOD

Question 15

-the time between inoculation and beginning of multiplication is known as?

note: no appreciable increase in number
of bacterial cell in this phase

Answer 15

LAG PHASE

Question 16

-This phase is characterized by rapid exponential cell growth of bacteria at their maximum rate.

note: the microbes are sensitive to antibiotics & antimicrobial agents

Answer 16

LOG PHASE

Question 17

• in this phase bacterial growth almost stops
  completely due to depletion of essential nutrients.

note: endospores starting to form in this phase.

Answer 17

STAIONARY PHASE

Question 18

-in this phase, the bacterial population declines due to death of cells due to.
1. AUTOLYTIC ENZYME
2. EXHAUSTION OF NUTRIENTS

Answer 18

DECLINE PHASE

Question 19

-Is a method utilized for industrial and research purpose that is achieved by using a special device for replenishing nutrients and removing bacterial population continuously so that bacteria growth is not inhibited due to lack of nutrients or due to accumulation of toxic bacterial metabolites

Answer 19

CONTINUES CULTURE

Question 20

-minimum and maximum temperature are only what?

Answer 20

30 degree celsius

Question 21

-is the lowest temperature at which a species will grow.

Answer 21

MINIMUM TEMPERATURE

Question 22

-this temperature is when a species grow best.

Answer 22

OPTIMUM TEMPERATURE

Question 23

-is the highest temperature at which a species can grow.

Answer 23

MAXIMUM TEMPERATURE

Question 24

-refers to the alkalinity or acidty of a solution.

Answer 24

pH

Question 25

-what is the neutral pH

Answer 25

6.5-7.5

Question 26

-is the pressure required to stop water/solution from
diffusing through a barrier by?

Answer 26

OSMOSIS or OSMOTIC PRESSURE

Question 27

• by osmosis. Microorganisms require water
  for growth and are made of water, how many percentage?

Answer 27

80-90%

Question 28

-when solution outside the cell has higher concentration of solutes than Inside the cell, water is diffused outside of cell and then the cell will SHRINKS

Answer 28

HYPERTONIC

Question 29

-When solution outside the cell has lower concentration of
solutes than inside the cell, water is diffused inside of cell and the cell SWELLS

Answer 29

HYPOTONIC

Question 30

-when concentrations in two solutions are same, so cell
will neither SWELL nor SHRINK

Answer 30

ISOTONIC

Question 31

-important for all organic compounds that make up a living cell;
-also cosist the half dry weight of bacteria

Answer 31

CARBON

Question 32

-helps form the amino group in amino acid.

Answer 32

NITROGEN

Question 33

-used to synthesize sulfur-containing amino acids and vitamins

Answer 33

SULPHUR

Question 34

-important in synthesis of ATP, nucleic acids and
phospholipids of cell membranes.

Answer 34

PHOSPHOROUS

Question 35

-minerals that are minimally required by microbes, and
are also essential in enzymatic reaction.

Answer 35

TRACE ELEMENTS

Question 36

• required by aerobic microorganisms, it is toxic
  to anaerobic bacteria like Clostridium tetanus.

Answer 36

OXYGEN

Question 37

-are essential organic compounds that cannot
be synthesized by an organism thus must be obtained from the environment

Answer 37

ORGANIC GROWTH FACTOR