bacterial growth requirments

Question 1

name physical requirements

Answer 1

temperature
PH
Osmotic pressure

Question 2

name chemical requirements

Answer 2

Carbon hydrogen nitrogen phosphorus sulphur oxygen

CHONPS

Question 3

why do bacteria require carbon

Answer 3

biosynthesis

Question 4

what are bacteria called that can use C02 as main source of energy

Answer 4

Autotrophs

Question 5

what are bacteria called that use organic sources of energy

Answer 5

heterotrophs

Question 6

define Growth factors

Answer 6

any compound which an organism needs for growth but cannot synthesise its self .
e.g- amino acids, vitamins

Question 7

all organisms require water. what is this expressed as?

Answer 7

water activity

Question 8

define water activity

Answer 8

measure of water avaliable for use by microorganisms

Question 9

most bacteria only grow well at what water activity

Answer 9

AW 0.98 or above

Question 10

what does cardinal temperatures mean?

Answer 10

the min, optimum and max temperature at which each organism can grow

Question 11

if a bacteria lives in extreme temperature it is called

Answer 11

extreamophile

Question 12

what bacteria live in the poles and have a optimum of 15 and a min of 0

Answer 12

psychrophiles

Question 13

what bacterias optimum temp is 20 and cannot grow above 40

Answer 13

psychrotrophs

Question 14

what bacteria has its optimum growth at 37-40

Answer 14

pathogens and commensal flora belong in this group

called MESOPHILES

Question 15

what bacterias optimum is 60

Answer 15

Thermophiles

Question 16

what happens to bacteria in a hypertonic solution

Answer 16

shrinks

Question 17

what happens to cells in a hypotonic solution

Answer 17

lysis/turgid

Question 18

what does a Osmophile do

Answer 18

tollerate sugar solutions

Question 19

what does a Xerophile do

Answer 19

tolerate dry conditions

Question 20

what does a Halophile do

Answer 20

need a certain amount of salt to grow

Question 21

what does hallotollerant mean

Answer 21

can tollerate high levels of salt

Question 22

do all organisms need oxygen

Answer 22

nope

Question 23

what do bacteria always need for metabolism

Answer 23

electron acceptor

Question 24

what bacteria grow only if oxygen is present

Answer 24

Obligate aerobes

Question 25

what bacteria only grow if oxygen is not present

Answer 25

obligate anaerobes

Question 26

what bacteria doesnt require oxygen but grows better with it

Answer 26

Facultative anaerobes

Question 27

what bacteria require a specific level of oxygen

Answer 27

Microaerophiles

Question 28

what bacteria grow equally well with or without oxygen

Answer 28

Aerotollerant

Question 29

what is PH

Answer 29

measure of the concentration of hydrogen ions

Question 30

what ph is an acid

Answer 30

below 7

Question 31

define acidophiles

Answer 31

organism which grows well in a acid environment

Question 32

define alkalophiles

Answer 32

organisms that grow well in alkaline environment

Question 33

what PH do most bacteria grow at

Answer 33

neutral ph between 6.5 and 7.5

Question 34

what ph do most yeast grow at

Answer 34

ph 5-6

Question 35

name the factors affecting microbial growth

Answer 35

temp, water availability, 02 availability, salt, ph