AP BIOLOGY UNIT 3 ENZYME EXAM
REVIEW QUESTIONS AND ANSWERS
endergonic reaction - ANSWER-A non-spontaneous chemical reaction in which free
energy is absorbed from the surroundings.
cooperativity - ANSWER-A kind of allosteric regulation whereby a shape change in
one subunit of a protein caused by substrate binding is transmitted to all the others,
facilitating binding of subsequent substrate molecules.
free energy - ANSWER-The portion of a biological system's energy that can perform
work when temperature and pressure are uniform throughout the system.
substrate - ANSWER-reactant of an enzyme-catalyzed reaction
catalyst - ANSWER-substance that speeds up the rate of reaction but is not
consumed
allosteric - ANSWER-A type of enzyme that changes its conformation and its
function in response to a modifier
competitive inhibition - ANSWER-substance that resembles the normal substrate
competes with the substrate for the active site; slows rate
noncompetitive inhibitor - ANSWER-A substance that reduces the activity of an
enzyme by binding to a location remote from the active site, changing its
conformation so that it no longer binds to the substrate.
denatured enzyme - ANSWER-when active site loses its shape and therefore its
function
optimal - ANSWER-Best or most favorable
allosteric site - ANSWER-A receptor site on the enzyme remote from the active site
which can be switched on or off.
Effect of temperature on enzyme activity - ANSWER-As temperature increases, so
does the rate of reaction up until the optimal temperature. After the optimal
temperature, the rate of reaction decreases because the enzyme is denatured.
Effect of pH on enzyme activity - ANSWER-pH affects ionization of the active site
ranges in pH above or below optimal can lead to denaturation of the active site
Effect of concentration on rate of reaction - ANSWER-Increasing the concentration of
a reactant (i.e. having more reactant particles per unit volume) will increase the rate
of reaction as there are more particles available to react at any one time, therefore
more collisions are likely to occur per unit time.
REVIEW QUESTIONS AND ANSWERS
endergonic reaction - ANSWER-A non-spontaneous chemical reaction in which free
energy is absorbed from the surroundings.
cooperativity - ANSWER-A kind of allosteric regulation whereby a shape change in
one subunit of a protein caused by substrate binding is transmitted to all the others,
facilitating binding of subsequent substrate molecules.
free energy - ANSWER-The portion of a biological system's energy that can perform
work when temperature and pressure are uniform throughout the system.
substrate - ANSWER-reactant of an enzyme-catalyzed reaction
catalyst - ANSWER-substance that speeds up the rate of reaction but is not
consumed
allosteric - ANSWER-A type of enzyme that changes its conformation and its
function in response to a modifier
competitive inhibition - ANSWER-substance that resembles the normal substrate
competes with the substrate for the active site; slows rate
noncompetitive inhibitor - ANSWER-A substance that reduces the activity of an
enzyme by binding to a location remote from the active site, changing its
conformation so that it no longer binds to the substrate.
denatured enzyme - ANSWER-when active site loses its shape and therefore its
function
optimal - ANSWER-Best or most favorable
allosteric site - ANSWER-A receptor site on the enzyme remote from the active site
which can be switched on or off.
Effect of temperature on enzyme activity - ANSWER-As temperature increases, so
does the rate of reaction up until the optimal temperature. After the optimal
temperature, the rate of reaction decreases because the enzyme is denatured.
Effect of pH on enzyme activity - ANSWER-pH affects ionization of the active site
ranges in pH above or below optimal can lead to denaturation of the active site
Effect of concentration on rate of reaction - ANSWER-Increasing the concentration of
a reactant (i.e. having more reactant particles per unit volume) will increase the rate
of reaction as there are more particles available to react at any one time, therefore
more collisions are likely to occur per unit time.
