EXAM 2 - BIOS 242 – CHAMBERLAIN questions and
answers 2025-2026 update
what is a heterotroph?-ANS >>organism that must obtain its carbon in organic form
what is an autotroph?-ANS >>an organism that uses inorganic CO2 as its carbon source
what is a phototroph?-ANS >>microbes that photosynthesize
what is a chemotroph?-ANS >>microbes that gain energy from chemical compounds
what is the temperature range for the optimal rate of growth for a psychrophile?-ANS >>0-15 degree
Celsius
what is the temperature range for the optimal rate of growth for a mesophile?-ANS >>20-40 degree
Celsius
what is the temperature range for the optimal rate of growth for a thermophile?-ANS >>45-80 degree
Celsius
what does a barophile require for growth?-ANS >>high hydrostatic pressure
what is an example of a barophile?-ANS >>deep sea microbes live in 1000x atmospheric pressure
what does a halophile require for growth?-ANS >>high concentration of salt (9-25% NaCl)
what are enzymes?-ANS >>biological catalysts that increase the rate of a chemical reaction
___ ___ is needed for a reaction to occur-ANS >>activation energy
true or false: enzymes lower the activation energy-ANS >>true
, enzymes act on reactant molecules known as ___-ANS >>substrates
enzymes bind and chemically change substrates into ___-ANS >>products
what is an apoenzyme?-ANS >>protein, composed of a sequence of amino acids
what is required for a holoenzyme?-ANS >>cofactors and coenzyme
cofactors are ___ elements-ANS >>inorganic
coenzymes are ___ elements-ANS >>organic
what are cofactos?-ANS >>metal ions that activate enzymes
cofactors help bring the ___ and substrate close together-ANS >>active site
true or false: cofactors do not directly participate in chemical reactions with the enzyme-ANS >>false
what the is main function of coenzymes?-ANS >>remove a chemical group from one substrate molecul
and add it to a substrate
what is the most important component of coenzymes?-ANS >>vitamins
what are the phases of the growth curve in a bacterial culture?-ANS >>lag phase, exponential growth/lo
phase, stationary growth phase, death phase
what is the lag phase?-ANS >>flat period on the graph when the population appears to not be growing
what are the reason growth lags?-ANS >>1. newly inoculated cells require a period of adjustmen
enlargement, and synthesis
2. the cells are not multiplying at max rate
3. the population of cells is sparse/dilute that the sample misses them
what is the exponential growth/log phase?-ANS >>the growth curve increase geometrically
during the exponential growth/log phase, the phase will continue as long as the cells have ...-AN
>>adequate nutrients and the environment is favorable
answers 2025-2026 update
what is a heterotroph?-ANS >>organism that must obtain its carbon in organic form
what is an autotroph?-ANS >>an organism that uses inorganic CO2 as its carbon source
what is a phototroph?-ANS >>microbes that photosynthesize
what is a chemotroph?-ANS >>microbes that gain energy from chemical compounds
what is the temperature range for the optimal rate of growth for a psychrophile?-ANS >>0-15 degree
Celsius
what is the temperature range for the optimal rate of growth for a mesophile?-ANS >>20-40 degree
Celsius
what is the temperature range for the optimal rate of growth for a thermophile?-ANS >>45-80 degree
Celsius
what does a barophile require for growth?-ANS >>high hydrostatic pressure
what is an example of a barophile?-ANS >>deep sea microbes live in 1000x atmospheric pressure
what does a halophile require for growth?-ANS >>high concentration of salt (9-25% NaCl)
what are enzymes?-ANS >>biological catalysts that increase the rate of a chemical reaction
___ ___ is needed for a reaction to occur-ANS >>activation energy
true or false: enzymes lower the activation energy-ANS >>true
, enzymes act on reactant molecules known as ___-ANS >>substrates
enzymes bind and chemically change substrates into ___-ANS >>products
what is an apoenzyme?-ANS >>protein, composed of a sequence of amino acids
what is required for a holoenzyme?-ANS >>cofactors and coenzyme
cofactors are ___ elements-ANS >>inorganic
coenzymes are ___ elements-ANS >>organic
what are cofactos?-ANS >>metal ions that activate enzymes
cofactors help bring the ___ and substrate close together-ANS >>active site
true or false: cofactors do not directly participate in chemical reactions with the enzyme-ANS >>false
what the is main function of coenzymes?-ANS >>remove a chemical group from one substrate molecul
and add it to a substrate
what is the most important component of coenzymes?-ANS >>vitamins
what are the phases of the growth curve in a bacterial culture?-ANS >>lag phase, exponential growth/lo
phase, stationary growth phase, death phase
what is the lag phase?-ANS >>flat period on the graph when the population appears to not be growing
what are the reason growth lags?-ANS >>1. newly inoculated cells require a period of adjustmen
enlargement, and synthesis
2. the cells are not multiplying at max rate
3. the population of cells is sparse/dilute that the sample misses them
what is the exponential growth/log phase?-ANS >>the growth curve increase geometrically
during the exponential growth/log phase, the phase will continue as long as the cells have ...-AN
>>adequate nutrients and the environment is favorable
