Energetics/Enzyme Worksheet-O-Rama
Name_______________________________________
Period_______
Date________________
In the blanks preceding each item, indicate if the first law of thermodynamics (I) or the second law of
thermodynamics (II) is best described.
You need to eat a good breakfast if you want to successfully think in first period
Evaporation of gasoline into the atmosphere
The creation of a snowman by children
The death and decay of an organism
Label each part of this molecule of ATP
What is the one word that you could use to
describe a. and b. together?
________________________________
What properties of c. cause the conversion of ATP into ADP to be spontaneous?
_______________________________________________________________________________________
Look at the picture below to answer the following 6 questions. Each question could have more than one answer.
Which
Which
Which
Which
Which
Which
bond is a peptide bond?
bond has the greatest polarity?
functional groups or R groups are hydrophobic?
functional groups or R groups are hydrophilic?
functional group is an amino group?
functional group or R group is an acid?
Enzymes
a.
b.
c.
d.
e.
Impart to substrates the kinetic energy they need to react.
May have at their active sites amino acids from widely different parts of a polypeptide chain.
Help align substrates so that the latter are oriented to each other in a very precise way.
Two of the above are correct.
a, b, c are correct
The conformation of a protein molecule depends upon several different types of bonds and group interactions. Which of
these remain intact when a protein is denatured?
a.
peptide bonds
b. ionic bonds
c. hydrophobic interactions d. hydrogen bonds e. none of the above
Match the items on the sketch below with the list of descriptions. Answers may be used once only.
7.
8.
A.
B.
C.
D.
E.
10.
9.
11.
Complementary active site of the enzyme
Enzyme, a protein with catalytic power
Substrate(s)
Enzyme/Substrate complex
Product
For the questions below, use the diagram above of a polypeptide chain. The heavy line represents the backbone of the
chain. Selected R groups of amino acids are shown together with various bonds and interactions that stabilize the
folding of the chain. Each bond or interaction is labeled with a roman numeral in parentheses.
Which of the atoms below are bonded together linearly to form the backbone of the chain?
a. C, H, and N
b. C, H, and O
c. C, and N
d. C and O
e. C, N, and O
Which of the bonds between R groups is (are) ionic bonds?
a. I
b. III
c. IV
d. III and IV
Which of the R group interactions is (are)hydrophobic?
a. I
b. II
c. I and II
d. III
e. I and II
e. III and IV
Which of the bonds between R groups is (are) hydrogen bonds(s)?
a. II
b. III c. IV
d. II and III
e. II and IV
A student learned that biological redox reactions occur if cells contain the enzyme
dehydrogenase. She wished to determine whether this enzyme is present in liver cells. She also knew
that methylene blue becomes colorless when it accepts hydrogen ions.
The student set up a series of test tubes numbered 1-5. The contents of each tube
(summarized in the chart below) were covered with a layer of mineral oil. Each tube was placed into a
water bath at 37C, which is approximately 99 F for 20 minutes.
The student’s question, “ Is enzyme present in liver cells?,” was answered by test tubes numbered
a. 1 & 2
b. 3 & 4
c. 4 & 5
d. 2 & 3
e. 1 & 5
Which tube served as the control group?
a. 1
b. 2
c. 3
d. 4
e. 5
An experiment is designed to measure the rate of maltase activity. Different amounts of maltose were
added to a system containing a fixed concentration of maltase. Which graph would MOST likely result from
plotting the data collected from the experiment?
Refer to the following figures to answer the following questions.
Which curve was generated using an enzyme taken from a bacterium that lives in hot springs at
temperatures of 70C or higher?
a. 1
b. 2
c. 3
d. 4
e. 5
The optimum temperature for enzyme 1 (curve 1) is approximately
a. 0C
b. 35C
c. 45C
d. 75C
e. Can not be determined
Which curves would be generated from analysis of an enzyme from a human small intestine where conditions
are slightly basic?
a. 1 & 4
b. 2 & 5
c. 3 & 4
d. 1 & 5
e. 3 & 5
An enzyme is classified as a:
a. Protein
b. Lipid
c. Carbohydrate
d. Nucleic Acid
Given what you know about enzymes, which of the following molecules is an enzyme?
a. amylose
b. sucrose
c. protease
d. nucleic acid
e. more than one of the above
Which of the following is a true statement about cofactors?
a. They are often necessary to facilitate enzyme-substrate binding
b. They are often vitamins
c. They are often minerals -- (metal ions) such as magnesium and iron
d. Two of the above are correct
e. All of the above are correct
Enzymes that function in the stomach cannot work well elsewhere in the digestive tract. This is probably
because:
a. The enzymes in the stomach only work at that particular temperature.
b. The enzymes in the stomach only work at that particular pH.
c. The enzymes in the stomach can only be used once.
d. All of the above
If the active site of an enzyme is small and contains mainly hydrophilic and positively charged residue (R)
groups, it would most readily bind with a substrate region which is
a. small, hydrophobic and positively charged
b. small, hydrophilic and positively charged
c. small, hydrophobic and negatively charged
d. small, hydrophilic and negatively charged
e. large, hydrophobic an positively charged
The enzyme succinic dehydrogenase normally catalyzes a reaction involving succinic acid. Another
substance, malonic acid, sufficiently resembles succinic acid to form temporary complexes with the
enzyme, although malonic acid itself cannot be catalyzed by succinic acid dehydrogenase.
In this example, succinic acid is
a. the substrate
b. the active site
Malonic acid is
a. the substrate
c. an inhibitor d. the product
b. a competitive inhibitor c. a cofactor d. a coenzyme e. a irreversible inhibitor
For the next question, also use the diagram to the right.
______ curve showing rate of product formation without the presence of malonic acid
- - - - - possible curves showing rate of product formation with presence of malonic acid
The solid line shows the reaction rate when a certain amount of the enzyme is added to 1M succinic acid.
Then the same amount of enzyme is added to 1 M succinic acid, but 0.5 M malonic acid is also present. Which
of the dotted-line curves best shows the new rate of succinic acid catalysis?
The reaction A + B - C + D is exergonic. All of the following procedures are effective in accelerating the
rate of the chemical reaction except
a. increasing the concentration of C & D
b. increasing the concentration of A & B
c. increasing the pressure on A & B
d. providing an appropriate catalyst
e. heating A and B together
Glucose will not burn in the air unless it is strongly heated. Why is this heat required?
a. Heat provides the activation energy
b. Heat acts as a catalyst
c. Heat lowers the average energy content of the molecules
d. Heat increases the net amount of energy released by the reation.
e. Heat changes exergonic reactions to endergonic reactions.
For the following 5 questions, use the diagram above, showing energy changes in the reaction
X + W  Y + Z. Answers may be used once, more than once, or not at all.
Which segment represents the energy of activation?
Which segment represents the amount of net free energy released by this reaction?
Which segment would be the same irrespective of whether the reaction was uncatalyzed or catalyzed by an
enzyme?
The above reaction is
a. exergonic b. endergonic
c. spontaneous
d. a and c are correct
The above reaction
a. would have a negative G.
b. would have a positive G.
c. could either have a negative or positive G, depending on the reactants and the temperature.
Which of the following statements is true of enzymes?
a. Enzymes lose some or all of their normal activity if their three dimensional structure is disrupted
b. Enzymes are composed of ribose, phosphate, and a nitrogen-containing base.
c. The activity of enzymes is independent of temperature and pH.
d. Enzymes provide the activation energy necessary to initiate a reaction.
e. An enzyme acts only once and is then destroyed.
Refer to the following information and graph. In an experiment, five test tubes were prepared, each
containing the same amount of starch and salivary amylase. Each of the five test tubes was
maintained at a different pH. After 10 minutes the amount of disaccharide in each test tube was
measured and recorded. The results are summarized in the graph below.
What is the product of the breakdown of starch by salivary amylase?
a. maltose b. fructose c. glucose d. glycogen
e. cellulose
The best explanation for the fact that the least amount of disaccharide was observed at pH 11 is that
a. competitive inhibition reduced the number of enzyme molecules free to react with substrate
b. substrate was not available to react with enzyme at pH 11
c. the number of collisions between substrate and enzyme decreased
d. the enzyme was denatured at pH 11
e. the activation energy increases at higher pH
What was the optimal pH for salivary amylase based on this experiment?
a. 3
b. 5
c. 7
d. 9
e. 11
The diagram on the right shows a biochemical pathway depicting the production
of various amino acids by the bacterium Escherichia coli. Answer the two
questions below on the basis of the diagram.
Three enzymes, E1, E2, and E3 convert aspartic acid to product A. These
enzymes are inhibited by negative feedback of lysine, methionine, and threonine
respectively. If there is an excess of lysine in the system, which statement
is True?
a.
b.
c.
d.
e.
No aspartic acid is converted to product A.
The production of product A is cut by approximately one-third.
There will be an increase in all three amino acids.
No threonine or methionine will be produced.
All of product A will be converted to isoleucine.
If a gene mutation occurs, resulting in a defect in E 7, which of the following statements is true?
a.
b.
c.
d.
e.
The production of product A will be cut by approximately one third.
The production of aspartic acid will be affected.
The production of lysine will cease
The production of isoleucine may decrease
The production of product C will be reduced