lecture 3 bacterial nutrition and growth

Question 1

what are micronutrients

Answer 1

required in small amounts

not required by all organisms

Question 2

what are macronutrients

Answer 2

required in large amounts

present in all cells

Question 3

bacterial growth stages

Answer 3

lag phase
exponetial phase
stationary phase
death phase

Question 4

what is binary fission

Answer 4

one cell divides into two

Question 5

how to measure bacterial growth

Answer 5

direct microscopic count
viable count (colony) with a serial dilution to obtain appropriate colony numbers
indirect measurment through turbidity (spectrophotometer)

Question 6

what else are macro elements needed for

Answer 6

enzyme activity
stabilises ribosomes, membranes, DNA
part of electron transport proteins

Question 7

what are the microelements

Answer 7

Copper
 Zinc
 Nickel
 Vanadium
 Selenium
 etc
components pf various enzymes

Question 8

what is culture media

Answer 8

nutrient solutions that provide all the elements required for growth

Question 9

what is a chemically defined medium

Answer 9

the exact chemical composition is known

Question 10

what is a complex media

Answer 10

the exact composition is NOT known

made of complex material such as milk protein, beef, yeast

Question 11

what is solid culture media

Answer 11

nutrient agar plates

Question 12

where is lipid culture media stored

Answer 12

erlenmeyer flasks

test tubes

Question 13

what is growth

Answer 13

increase in cell numbers

Question 14

how does most bacteria grow

Answer 14

binary fission

one cell divides into two

Question 15

what is a generation

Answer 15

when one cell turns to two one generation has occured

Question 16

what is doubling time

generation time

Answer 16

time needed for generation to double

Question 17

what is exponention growth shown as on a graph

Answer 17

in logarithms

Question 18

what is a batch culture

Answer 18

culture grown in a closed system

Question 19

heterotrophs

Answer 19

require organic molecules made by other organisms

Question 20

autotrophs

Answer 20

co2 is the principal carbon source

Question 21

autotrophs

Answer 21

co2 is the principal carbon source

Question 22

phototrophs

Answer 22

use light energy to produce ATP

Question 23

chemotrophs

Answer 23

oxidise organic or inorganic compounds

Question 24

what are the environmental factors that effect bacterial growth

Answer 24

oxygen
temp
pH
osmolarity

Question 25

obligate aerobes

Answer 25

need o2

Question 26

obligate anerobes

Answer 26

cannot grow in the presence of o2

Question 27

facultative anerobes

Answer 27

can grow with or without o2

Question 28

aerotolerant anaerobes

Answer 28

dont need o2 but tolerate it

Question 29

microaerophilic

Answer 29

need o2 but only tolerate it at low concs

Question 30

below 15 as opt temp dont grow above 20 cant grow below 0

Answer 30

psychrophiles

Question 31

around 20 -40 as opt temp body temp 37

Answer 31

mesophiles

Question 32

around 45 - 80 as opt temp

Answer 32

thermophiles live in hot springs compost heaps

Question 33

above 80 as opt temp

Answer 33

hyperthermophiles | live in hot springs

Question 34

current record holder

Answer 34

Geogemma barossii - grows between 80-121 °C - survives at least 2 hours at 130 °C

Question 35

acidophiles

Answer 35

prefer pH below 7

Question 36

alkaliphiles

Answer 36

prefere pH above 7

Question 37

mild halophiles

Answer 37

1-6% NaCl

Question 38

moderate halophile

Answer 38

7-15% NaCl

Question 39

extreme halophiles

Answer 39

15-30% NaCl