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Biology 30
Practice Exam 2 Questions
Bioenergetics/Enzymes
1. Glucose molecules provide energy to power the swimming motion of sperm. In this example, the sperm are changing:
a) chemical energy into kinetic energy;
b) chemical energy into potential energy;
c) kinetic energy into potential energy;
d) kinetic energy into chemical energy.
2. When an enzyme catalyzes a reaction; it?
a) lowers the amount of energy that is required to get the reaction going;
b) raises the amount of energy that is required to get the reaction going;
c) becomes the product of the reaction;
d) acts as the reactant.
3. After you have broken down your breakfast items into simpler products. The chemical reactions that result in the
building of more complex molecules are referred to as
reactions.
a) anabolic;
b) catabolic;
c) dehydration;
d) none of these.
4. Three or four of the following statements concerning enzymes are true and correct. Which one, if any, is NOT correct?
If all the statements are correct, choose "All of the above."
a) Enzymes are proteins;
b) An enzyme is not consumed (or used up) by the catalytic process;
c) An enzyme is very specific in terms of which substrates it can bind to;
d) An enzyme lowers the activation energy of a chemical reaction
e) all of these are correct statements regarding enzymes.
5. Which of these statements about enzyme inhibitors is true?
a) A competitive inhibitor binds to the enzyme outside the active site;
b) the action of competitive inhibitors may be reversible or irreversible;
c) A noncompetitive inhibitor does not change the shape of the active site;
d) When the product of an enzyme or an enzyme sequence acts as its inhibitor, this is known as positive feedback;
e) Antibiotics and pesticides generally do not act on enzymes, but rather affect the genetic code of their victims.
6. A reaction is designated as exergonic rather than endergonic when ___________.
a) activation energy exceeds net energy release;
b) activation energy is necessary;
c) no kinetic energy is released;
d) the potential energy of the products is less than the potential energy of the reactants;
e) it absorbs more energy.
7. The first law of thermodynamics ____________.
a) states that energy is neither created not destroyed;
d) states that entropy spontaneously increases;
b) deals with entropy; c) deals with heat content;
e) predicts the direction of a reaction.
8. Which of these is exhibiting kinetic energy?
a) a rock on a mountain ledge;
b) the high energy phosphate bonds of ATP;
c) an archer with a flexed bow;
d) a space station orbiting Earth; e) a person sitting on a couch while watching TV.
9. Which of the following do enzymes work on?
a) substrates;
b) products;
c) inhibitors;
d) competitive inhibitors;
e) dynamite.
10. The cells of an ant and an elephant are, on average, the same small size; an elephant just has more of them. What is
the advantage of small cell size?
a) small cells are less likely to burst than large cell;
b) small cells are less likely to be infected by bacteria;
c) small cells can better take up what they need from their environment;
d) it takes less energy to make an organism out of small cells;
e) small cells can "morph" more easily than larger cells.
11. Which of the following does not contain DNA?
a) nucleus;
b) chloroplast;
c) mitochondria;
d) bacteria;
e) you;
ab) all of these contain DNA.
12. In eukaryotes, the electron transport chain is a series of electron carrier molecules embedded in which
organelle?
a) the smooth ER;
b) the rough ER;
c) plasma membrane;
d) mitochondria
13. The net gain of ATP for each glucose molecule that enters glycolysis is, in the absence of oxygen,
approximately?
a) 38 ATP; b) 4 ATP;
c) 2 ATP;
d) 0 ATP; e) hum…
14. What is the name of the process in which pyruvate is converted to lactate?
a) chemiostic theory; b) fermentation; c) glycolysis;
d) citric acid cycle
15. Enzymes such as succinic acid dehydrogenase (SDH) are important in the citric acid cycle. They can be found?
a) cytosol;
b) mitochondrial matrix;
c) inner membrane of the mitochondria;
d) thylakoid;
e) damn…I should have paid more attention yesterday!
16. The molecule that serves as the final electron acceptor in cellular respiration is?
a) O2;
b) CO2;
c) water;
d) ATP;
e) beer.
17. After learning about cellular respiration, you decide to do an experiment where you fed mice with glucose (C 6H12O6) in
which the oxygen portion was radioactively labeled. You monitored the mice closely, and in a few minutes radioactive
oxygen atoms from the glucose showed up in: (Hint look at the cellular respiration equation)
a) CO2; b) NADH;
c) H2O; d) ATP;
e) O2;
ab) Damn, I knew I shouldn’t have fallen asleep.
18. Which of the following is NOT needed for DNA replication?
a) ribosomes; b) DNA;
c) nucleotides;
d) enzymes;
e) all of the above are needed
19. DNA replication is said to be semiconservative. This means that _____.
a) half of the old strand is degraded and half is used as a template for the replication of a new strand
b) one of the two resulting double helices is made of two old strands, and the other is made of two new strands
c) the old double helix is degraded and half of its nucleotides are used in the construction of two new double helices
d) one strand of the new double helix is made of DNA and the other strand is made of RNA
e) each new double helix consists of one old and one new strand
20. The flow of information in a cell proceeds _____.
a) from RNA to DNA to protein;
b) from protein to RNA to DNA;
d) from RNA to protein to DNA;
e) from DNA to RNA to protein
c) from DNA to protein to RNA
21. The information carried by a DNA molecule is in _____.
a) its amino acid sequence;
b) the sugars and phosphates forming its backbone
c) the order of the nucleotides in the molecule
d) the total number of nucleotides it contains
e) the RNA units that make up the molecule
22. How does RNA polymerase know where to start transcribing a gene into mRNA?
a) It starts at one end of the chromosome.
b) Transfer RNA acts to translate the message to RNA polymerase.
c) It starts at a certain nucleotide sequence called a promoter.
d) The ribosome directs it to the correct portion of the DNA molecule.
e) It looks for the AUG start codon.
23. After an RNA molecule is transcribed from a eukaryotic gene, portions called ____ are removed and the remaining
____ are spliced together to produce an mRNA molecule with a continuous coding sequence.
a) operators ... promoters;
b) exons ... introns;
c) silencers ... enhancers;
d) introns ... exons;
e) promoters ... operators
24. Which of the following processes occurs in the cytoplasm of a eukaryotic cell?
a) DNA replication;
b) translation;
c) transcription;
d) DNA replication and translation
e) translation and transcription
25. Which one of the following is true of tRNAs?
a) Each tRNA binds a particular amino acid.
c) tRNAs carry special sequences known as codons.
e) All of the above.
b) tRNAs are extremely small molecules.
d) There are four types of tRNA.
26. A mutagen causes _____.
a) problems with mitosis;
b) a change in the base sequence of DNA;
c) blockage of the ribosome-binding sites;
d) decreased permeability of the nuclear envelope
e) a reduction in the number of tRNA molecules available for protein synthesis
27. A gene is usually _____.
a) the same thing as a chromosome
b) the information for making a polypeptide
c) made of RNA
d) made by a ribosome
e) made of protein.
28. Which of the following is why you and your siblings (if you have any) are different?
a) crossing over;
b) independent assortment;
c) random fertilization;
d) all of these.
29. Which one of the following is a difference between sexual and asexual reproduction?
a) regeneration is exclusive to sexual reproduction;
b) sexual reproduction produced more offspring;
c) sexual reproduction includes the development of unfertilized eggs;
d) sexual reproduction is more likely to increase genetic variation than is asexual reproduction;
e)asexual reproduction always increase the number of sets of chromosomes in the offspring whereas sexual
reproduction decreases the number of sets of chromosomes in the offspring.
30. If the S-phase of interphase was eliminated from the cell cycle, the daughter cells at the end of mitosis would:
a) have half the genetic material as the parent cell;
c) be genetically identical to the parent cell;
b) be genetically identical;
d) none of these are correct choices.
31. You’re a researcher for a drug company. Which of the following candidate drugs would be worth developing as a
cancer chemotherapy agent? A drug that:
a) causes cells to divide at a right angle from their usual orientation;
b) interferes with cellular respiration;
c) prevents sister chromatids from separating at anaphase;
d) prevents crossing over;
e) prevents tetrad formation.
32. Which one of the following is not a function of mitosis? Mitosis helps organisms:
a) grow;
b) regenerate lost parts;
c) reproduce asexually;
d) repair tissues;
e) all of these.
33. Using the following sentence: “Where is the dog?” Which one of the following variations of this sentence is most like
a chromosomal deletion?
a) Where is the dog?
d) Where is dog?
b) Where is the the dog;
e) Where is dog the?
c) Where is is is the dog?
ab) what the heck…
34. Which of the following is the most significant difference between mitosis and meiosis?
a) chromosomes are duplicated twice before mitosis;
c) homologous chromosomes separate during meiosis;
b) meiosis is not followed by cytokinesis;
d) a spindle formed of microtubules moves chromosomes.
Use the following diagram to answer the next three questions:
d
a
b
c
35. The phase in which enzymes copies the genetic material.
36. The phase in which is the reverse of prophase.
37. The phase just prior to sister chromatid separation.
e