Download Practice Q Ch 8 metabolism with key

BIO 101
Practice questions Ch 8 STUDY NOTES AND TEXTBOOK BEFORE ATTEMPTING THESE. This is
NOT COMPREHENSIVE (does not contain all the information you need to study for the exam. Consult notes
and textbook)
1. Choose the pair that completes this sentence: Catabolism is to anabolism as ___ is to __
a. Exergonic: spontaneous
b. Exergonic: endergonic
c. Heat: entropy
d. First law of thermodynamics: second law
16.
2. Which of the following metabolic processes can occur without a net influx of energy?
a.
b.
c.
d.
ADP +
→ ATP + H2O
C6H12O6 + 6 O2 → 6 CO2 + 6 H2O
6 CO2 + 6 H2O → C6H12O6 + 6 O2
amino acids → protein
3. If an enzyme in solution is saturated with substrate, the most effective way to obtain a faster
yield of products products is to
a. add more enzyme.
b. heat the solution to 90°C.
c. add more substrate.
d. add a noncompetitive inhibitor.
4. Some bacteria are metabolically active in hot springs because
a. they are able to maintain a lower internal temperature.
b. high temperatures make catalysis unnecessary.
c. their enzymes have high optimal temperatures
d. their enzymes are insensitive to temperature
5. Using a series of arrows, draw the branched metabolic reaction pathway described by the following
statements, and then answer the question at the end. Use red arrows and minus signs to indicate inhibition.
L forms M and N.
M can form O.
O can forms P and R.
P can form Q.
R can form S.
O inhibits the reaction of L to form M.
Q inhibits the reaction of O to form P.
S inhibits the reaction of O to form R
Which reaction(s) would occur if both Q and S were present in the cell in high concentrations?
a. L  M
b. M O
c. L N
d. O P
e. R S
BIO 101
6. Examine the following reaction, and then answer the questions below:
The enzyme in this reaction is... _________________________
The product in this reaction is... ________________________
The substrate in this reaction is.. _________________________
7. An enzyme is made of:
a. carbohydrate
b. protein
c. nucleic acid
d. lipid
8. Which of the following enzymes would digest a fat?
a. sucrase
b. fatose
c. protease
d. lipase
9.
Competitive inhibitors stop an enzyme from working by
a. changing the shape of the enzyme
b. merging with the substrate instead
c. blocking the active site of the enzyme
d. combining with the product of the reaction
10. When a molecule binds to an area of an enzyme that is not the active site, and changes the
shape of the enzyme so that it no longer can work, this is called
a. denaturation
b. competitive inhibition
c. noncompetitive inhibition
d. substrate delocation
11. In an enzymatic reaction, the amount of _____ determines the amount of product produced.
a. catalyst
b. reactant
c. enzyme
d. water
12. An enzyme:
a. is a substrate
b. is a carbohydrate
c. is used up in a reaction
d. none of the above
BIO 101
13. Exergonic reactions:
a. release energy
b. are spontaneous reactions
c. can be coupled to endergonic reactions
d. All statements are true
14. Consider the reaction: Glucose + ATP  Glucose-6-phosphate + ADP
Δ G is + 12.6 kJ/mol.
a. The reaction is endergonic and thus makes free energy available to fuel life processes
b. The reaction requires free energy and thus is endergonic
c. This is an exergonic reaction which is spontaneous and makes energy available
d. The reaction requires free energy and is exergonic
15. Enzymes influence chemical reactions in living systems by
a. providing the substrate required for the reaction to occur
b. affecting the rate at which reactions occur
c. absorbing water released when polymers are formed
d. combining with excess hydrogen to form gaseous wastes
16. An enzyme that digests the sugar, amylose, will not act upon maltose. This is an indication that enzymes
are
a. proteins
b. specific
c. catalytic
d. synthetic
17. Here are of some stages of an enzyme-controlled reaction.
Label: enzyme, product(s), substrate, enzyme/substrate complex
18. Shown below is a graph describing energy versus reaction coordinate for a catalyzed and uncatalyzed
reaction. Fill in the blanks with the letter that corresponds to each stage of the graph.
_____ ES
_____ S (substrate)
_____ P (product)
_____ Uncatalyzed reaction
BIO 101
19. Enzymes are classified by the:
a. Size of enzyme b. size of substrate c. reaction catalyzed
d. rate of reaction
20. Which of the following is uncharacteristic of ATP?
A. It is formed by attaching a phosphate group to ADP with a high energy bond
B. In most reactions involving ATP, the outer, high energy bond is broken
C. ATP is a good long term energy storage molecule
D. When dephosphorylated, ATP becomes ADP
a.
21. Enzyme B requires Zn2+ in order to catalyze the conversion of substrate X. The zinc is best
identified as a(n): a. coenzyme b. cofactor c. substrate d. product e. enzyme
22. Which of the following is not true concerning ATP?
a. When utilized, ADP is the end product
b. ATP contains three phosphates
c. ATP stands for adenosine triphosphate
d. When broken down, the reaction is endergonic
23. Which of the following situations does not represent a transformation of one type of
energy to another?
a.
b.
c.
d.
The burning of gas in a car to move a car
The production of sugar by photosynthesis
A collision between one ball and another ball causing both to move
The production of electrical power by damming a river
24. In general, use of ATP drives cellular work by:
a. Changing to ADP and P
b. Releasing free energy that can be coupled to other reactions
c. Releasing heat
d. Lowering the free energy of a reaction
25. What is meant by “induced fit”?
a. The substrate can be altered so that it is induced to fit into the enzyme’s active site
b. The enzyme structure is altered so that it can be induced to fit many types of
substrate
c. Substrate binding induces the enzyme to alter is shape slightly
d. The shape of the active site is perfect for the substrate
1. B 2. B 3. A 4. C 5. A, B, C
6. Oxidase, benzoquin. Catechol. 7B. 8D. 9. C 10. C 11. B
12. D 13. A 14. B 15. B 16. B. 17. D = enzyme C = products A = substrate B = ES complex 19. C
20. C 21. B 22. D 23. C 24. B 25. C