BCHS 3304 Exam 1 Material Questions and
CORRECT Answers
enzyme
Definition: a protein which carries out a chemical reaction
protected, orientation
What are the two methods through which enzymes catalyze reactions?
- providing _________________ environment
- providing all reactive partners in correct ________________
high, mild, high, high
Generally, enzymes have:
1. ___________ reaction rates (high/low)
2. ____________ reaction conditions (extreme/mild)
3. _______________ specificity (high/low)
4. _______________ regulation (high/low)
rate enhancement
What is x in the following equation?
[ x = enzymatic reaction rate / nonenzymatic rate]
oxidoreductase, transferase, hydrolase, lyase, isomerase, ligase
What are the 6 classifications of enzymes?
,transferase
Classification: Which class of enzymes involves the transfer of functional groups?
hydrolase
Classification: Which class of enzymes involves hydrolysis?
lyase
Classification: Which class of enzymes involves elimination of a group to form double bonds?
ligase
Classification: Which class of enzymes involves bond formation with ATP hydrolysis?
complimentarity
_______________ between enzyme and substrate is the basis of the lock and key model.
induced fit model
Definition: The enzyme-substrate model in which the binding pockets can be adjusted.
F (enzymatic reactions are HIGHLY stereospecific)
T/F: Enzymatic reactions are not stereospecific
chiral, chiral
Are enzymes composed of achiral or chiral amino acids? If a substrate were achiral, what would
the chirality be of the product?
no
Does every enzyme require cofactors?
,cofactor
Definition: non protein elements of some enzymes that can be broken down to many subgroups
coenzymes
Along with metal ions, __________________ are a subgroup of cofactors and are
organic/biological cofactors
cosubstrates , prosthetic groups
There are two subgroups of coenzymes:
1. ____________ transiently/temporarily associated coenzymes
2. _____________ __________ permanently enzyme associated.
holoenzyme
Definition: the name for the catalytically ACTIVE enzyme-cofactor complex
apoenzyme
Definition: the catalytically INACTIVE protein as a result of the removal of the cofactor.
reaction coordinate
Definition: the path of minimum free energy which reactants approach one another
transition state
Definition: representative of the free energy maxima
activation energy, overall free energy
, ΔG++ represents:
while ΔG represents:
highest, slowest
The rate determining/limiting step will have the ________________ (highest/lowest) activation
energy as is the ____________ step (fastest/slowest)
transition states, intermediates
In a two step reaction with two "hills", what do the tops and troughs of the hills represent,
respectively?
T
T/F: enzymes and catalysts can reduce the activation energy of both the forward and reverse
reactions
F (enzymes can't alter overall free energy)
T/F: enzymes can alter both ΔG++ and ΔG
acid-base catalysis
What type of catalysis is sensitive to pH since charged amino acid ionization is affected?
neutral
What type of pH, acidic basic or neutral maximize enzyme efficiency?
low
Is enzyme activity higher at low or high temperature?
CORRECT Answers
enzyme
Definition: a protein which carries out a chemical reaction
protected, orientation
What are the two methods through which enzymes catalyze reactions?
- providing _________________ environment
- providing all reactive partners in correct ________________
high, mild, high, high
Generally, enzymes have:
1. ___________ reaction rates (high/low)
2. ____________ reaction conditions (extreme/mild)
3. _______________ specificity (high/low)
4. _______________ regulation (high/low)
rate enhancement
What is x in the following equation?
[ x = enzymatic reaction rate / nonenzymatic rate]
oxidoreductase, transferase, hydrolase, lyase, isomerase, ligase
What are the 6 classifications of enzymes?
,transferase
Classification: Which class of enzymes involves the transfer of functional groups?
hydrolase
Classification: Which class of enzymes involves hydrolysis?
lyase
Classification: Which class of enzymes involves elimination of a group to form double bonds?
ligase
Classification: Which class of enzymes involves bond formation with ATP hydrolysis?
complimentarity
_______________ between enzyme and substrate is the basis of the lock and key model.
induced fit model
Definition: The enzyme-substrate model in which the binding pockets can be adjusted.
F (enzymatic reactions are HIGHLY stereospecific)
T/F: Enzymatic reactions are not stereospecific
chiral, chiral
Are enzymes composed of achiral or chiral amino acids? If a substrate were achiral, what would
the chirality be of the product?
no
Does every enzyme require cofactors?
,cofactor
Definition: non protein elements of some enzymes that can be broken down to many subgroups
coenzymes
Along with metal ions, __________________ are a subgroup of cofactors and are
organic/biological cofactors
cosubstrates , prosthetic groups
There are two subgroups of coenzymes:
1. ____________ transiently/temporarily associated coenzymes
2. _____________ __________ permanently enzyme associated.
holoenzyme
Definition: the name for the catalytically ACTIVE enzyme-cofactor complex
apoenzyme
Definition: the catalytically INACTIVE protein as a result of the removal of the cofactor.
reaction coordinate
Definition: the path of minimum free energy which reactants approach one another
transition state
Definition: representative of the free energy maxima
activation energy, overall free energy
, ΔG++ represents:
while ΔG represents:
highest, slowest
The rate determining/limiting step will have the ________________ (highest/lowest) activation
energy as is the ____________ step (fastest/slowest)
transition states, intermediates
In a two step reaction with two "hills", what do the tops and troughs of the hills represent,
respectively?
T
T/F: enzymes and catalysts can reduce the activation energy of both the forward and reverse
reactions
F (enzymes can't alter overall free energy)
T/F: enzymes can alter both ΔG++ and ΔG
acid-base catalysis
What type of catalysis is sensitive to pH since charged amino acid ionization is affected?
neutral
What type of pH, acidic basic or neutral maximize enzyme efficiency?
low
Is enzyme activity higher at low or high temperature?
