AP BIO CHAPTER 6: METABOLISM:
ENERGY AND ENZYMES EXAM
QUESTIONS WITH COMPLETE
SOLUTIONS
metabolic pathway - ANSWER--an orderly sequence of linked reactions; each step is
catalyzed by a specific enzyme.
-metabolic pathways begin with a particular reactant, end with end product, and have
many intermediate steps
-one pathway leads to the next; since pathways have the same molecules, one
pathway can lead to several others
-energy released in small increments is more useful
enzymes - ANSWER--catalysts that speed chemical reactions without the enzyme
being changed
-every enzyme is specific in its action and catalyzes only one reaction or one type of
reaction
-each step in a series of chemical reactions is assisted by an enzyme
-in a cell, an enzyme is analogous to a friend because it brings together particular
molecules and causes them to react with one another
enzymatic reactions - ANSWER-- A to F are reactants and B to G are products
-products from previous reaction become the reactant for the next
-E1 to E6 are enzymes
-A is the substrate for E1 and B is the product; B becomes substrate for E2
substrate - ANSWER-- a reactant for an enzymatic reaction
-A is the substrate for E1, and B is the product. Now B becomes the substrate for E2,
and C is the product... and so on.
reactant - ANSWER-a substance that participates in a reaction; a product is
substance formed by the reaction.
activiation energy - ANSWER--the energy that must be added to cause molecules to
react with one another
-molecules often do not react with each other unless activated in some way
-for metabolic reactions to occur in a cell, an enzyme must usually be present
-without enzymes, activation is achieved by heating reaction flask to increase
molecular collisions
enzyme-substrate complex - ANSWER--enzymes speed up chemical reactions by
lowering the activation of energy by forming a complex with their substrates at the
active site
-only a small amount of enzyme is needed in a cell because enzymes are not used
up.
-some enzymes actually participate in the reaction (ex. trypsin)
, - a particular reactant(s) may produce more than one type of product(s)
a. presence or absence of enzyme determines which reaction takes place
b. if reactants can form more than one product, the enzymes present determine
product produced.
-every cell reaction requires its specific enzyme; enzymes are named for substrates
by adding "-ase"
-reaction can be degradation/synthesis
-substrate attaches on active site
-active site undergoes a slight change in shape called "induced fit model"
-this facilitates reaction to occur
-active site returns to original shape after reaction is complete; ready to bind to
another
active site - ANSWER-an active site of a small region on the surface of the enzyme
where the substrate(s) bind.
-when a substrate binds to an enzyme, the active site undergoes a slight change in
shape that facilitates the reaction
how enzymes work - ANSWER--small amount of enzyme is needed; enzymes are
not used up in reaction
-some enzymes do participate in reaction, example- active site of 'trypsin' contains 3
amino acids
-it first breaks the peptide bond, then adds water
requirements for enzymatic reaction - ANSWER--reactant may produce more than
one type of product
-presence or absence of enzyme determines which reaction will take place
-every reaction requires a specific enzyme
-enzymes are named for their substrate
Enzymatic speed - ANSWER--the rate of a reaction is the amount of product
produced per unit time
-to achieve maximum product per unit time, there should be enough substrate to fill
active sites, and adequate temperature and pH
How substrate concentration affects enzymatic speed - ANSWER--increase in
substrate concentration increases enzyme activity because there are more collisions
between substrate molecules and the enzyme
-more substrate means more product per unit time, but rate of activity can not
increase any more if active sites are filled (maximum rate has reached)
how temperature and pH affect enzymatic speed - ANSWER--as temperature rises,
enzyme activity increases because there are more molecular collisions at warmer
temperatures
-enzyme activity declines rapidly when temperature rises beyond a certain point
because the enzyme is denatured; results in a change in the shape of enzyme (won't
bind to active site sufficiently)
-each enzyme has optimal pH that maintains its normal configuration
ENERGY AND ENZYMES EXAM
QUESTIONS WITH COMPLETE
SOLUTIONS
metabolic pathway - ANSWER--an orderly sequence of linked reactions; each step is
catalyzed by a specific enzyme.
-metabolic pathways begin with a particular reactant, end with end product, and have
many intermediate steps
-one pathway leads to the next; since pathways have the same molecules, one
pathway can lead to several others
-energy released in small increments is more useful
enzymes - ANSWER--catalysts that speed chemical reactions without the enzyme
being changed
-every enzyme is specific in its action and catalyzes only one reaction or one type of
reaction
-each step in a series of chemical reactions is assisted by an enzyme
-in a cell, an enzyme is analogous to a friend because it brings together particular
molecules and causes them to react with one another
enzymatic reactions - ANSWER-- A to F are reactants and B to G are products
-products from previous reaction become the reactant for the next
-E1 to E6 are enzymes
-A is the substrate for E1 and B is the product; B becomes substrate for E2
substrate - ANSWER-- a reactant for an enzymatic reaction
-A is the substrate for E1, and B is the product. Now B becomes the substrate for E2,
and C is the product... and so on.
reactant - ANSWER-a substance that participates in a reaction; a product is
substance formed by the reaction.
activiation energy - ANSWER--the energy that must be added to cause molecules to
react with one another
-molecules often do not react with each other unless activated in some way
-for metabolic reactions to occur in a cell, an enzyme must usually be present
-without enzymes, activation is achieved by heating reaction flask to increase
molecular collisions
enzyme-substrate complex - ANSWER--enzymes speed up chemical reactions by
lowering the activation of energy by forming a complex with their substrates at the
active site
-only a small amount of enzyme is needed in a cell because enzymes are not used
up.
-some enzymes actually participate in the reaction (ex. trypsin)
, - a particular reactant(s) may produce more than one type of product(s)
a. presence or absence of enzyme determines which reaction takes place
b. if reactants can form more than one product, the enzymes present determine
product produced.
-every cell reaction requires its specific enzyme; enzymes are named for substrates
by adding "-ase"
-reaction can be degradation/synthesis
-substrate attaches on active site
-active site undergoes a slight change in shape called "induced fit model"
-this facilitates reaction to occur
-active site returns to original shape after reaction is complete; ready to bind to
another
active site - ANSWER-an active site of a small region on the surface of the enzyme
where the substrate(s) bind.
-when a substrate binds to an enzyme, the active site undergoes a slight change in
shape that facilitates the reaction
how enzymes work - ANSWER--small amount of enzyme is needed; enzymes are
not used up in reaction
-some enzymes do participate in reaction, example- active site of 'trypsin' contains 3
amino acids
-it first breaks the peptide bond, then adds water
requirements for enzymatic reaction - ANSWER--reactant may produce more than
one type of product
-presence or absence of enzyme determines which reaction will take place
-every reaction requires a specific enzyme
-enzymes are named for their substrate
Enzymatic speed - ANSWER--the rate of a reaction is the amount of product
produced per unit time
-to achieve maximum product per unit time, there should be enough substrate to fill
active sites, and adequate temperature and pH
How substrate concentration affects enzymatic speed - ANSWER--increase in
substrate concentration increases enzyme activity because there are more collisions
between substrate molecules and the enzyme
-more substrate means more product per unit time, but rate of activity can not
increase any more if active sites are filled (maximum rate has reached)
how temperature and pH affect enzymatic speed - ANSWER--as temperature rises,
enzyme activity increases because there are more molecular collisions at warmer
temperatures
-enzyme activity declines rapidly when temperature rises beyond a certain point
because the enzyme is denatured; results in a change in the shape of enzyme (won't
bind to active site sufficiently)
-each enzyme has optimal pH that maintains its normal configuration
