PROPERTIES OF WATER AND MACROMOLECULES HW
AP BIOLOGY
DR. WEINER
1. In a single water molecule, two H atoms are bonded to the O atom by
a. Ionic bonds
b. Polar covalent bonds
c. Nonpolar covalent bonds
d. Hydrogen bonds
2. Between two water molecules, the H atoms of one water molecule are bonded to the O atoms of
another by
a. Ionic bonds
b. Polar covalent bonds
c. Nonpolar covalent bonds
d. Hydrogen bonds
3. The reason water can form hydrogen bonds is due to
a. The great difference in electronegativities between O and H
b. The similarities in electronegativities between O and H
c. Their ability to form ionic bonds
d. Their ability to form nonpolar covalent bonds
4. Which of the following effects is produced by the high surface tension of water?
a. Lakes don’t freeze solid in winter despite the low temperatures
b. A water strider can walk across the surface of water
c. Evaporation of sweat from skin helps cool people
d. Water flows up from the roots in a plant
5. Liquid water’s high specific heat is mainly a consequence of the
a. Small size of water molecules
b. higher density of liquid water that ice
c. high specific heat of the hydrogen and oxygen atoms
d. absorption and release of heat when hydrogen bonds break and form
6. Why does ice float in water?
a. the high surface tension of liquid water keep ice on top
b. ice always has air bubble that keep it afloat
c. hydrogen bonds stabilize and keep the molecules in ice farther apart than water molecules
of liquid water
d. the crystalline lattice of ice causes it to be denser than liquid water
7. When an ionic compound such as sodium chloride (NaCl) is placed in water, the components of the
NaCl crystal dissociate into individual Na+ and Cl- ions. In contrast, the atoms of covalently
bonded compounds like glucose do not dissociate in water. which of the following would have the
greatest number of solute molecules?
a. 1L of 0.5M NaCl
b. 1L of o.5M glucose
c. 1L of 1M NaCl
d. 1 L of 1 M glucose
8. What is the pH of a solution with [OH-] concentration of 10-12 M?
a. pH 2
b. pH 12
c. pH 10
d. pH 4
9. If the pH of a solution is increased from 5 to 7, it means that the
a. concentration of OH- is 100x more than it was at pH 5
b. concentration of OH- is 2x more than it was at pH 5
c. concentration of H+ is 100x more than it was at pH 5
d. concentration of H+ is 2x more than it was at pH 5
10. One liter of a solution at pH 2 has how many more H+ ions than I L of a solution at pH 6?
a. 10 times
b. 40 times
c. 10000 times
d. 40000 times
One of the buffers that contributes to pH stability in human blood is carbonic acid, H2CO3. It is a
weak acid that dissociates into bicarbonate (HCO3-) and H+ according to the following equation
H2CO3↔HCO3- + H+
11. If the pH of the blood drops, one would expect EXPLAIN WHY
a. The HCO3- to act as a base and remove H+ ions with the formation of H2CO3
b. The HCO3- to act as an acid and remove H+ ions with the formation of H2CO3
c. The concentration of HCO3- to increase
d. The concentration of H2CO3 to decrease
12. If the pH of the blood increases, one would expect EXPLAIN WHY
a. A decrease in the concentration of H2CO3 and an increase in the concentration of HCO3b. An increase in the concentration of of H2CO3 and a drcrease in the concentration of
HCO3c. a decrease in the concentration of HCO3- and an increase in the concentration of H+
d. an increase in the concentration of HCO3- and an decrease in the concentration of OH-
temperature
13. Identical heat lamps are arranged to shine on identical containers of water and methanol so that
each liquid absorbs the same amount of energy per minute. The covalent bonds of methanol are
nonpolar, so there are no hydrogen bonding among methanol molecules. Which of the following
graphs correctly describes what will happen to the temperature of the water and methanol?
EXPLAIN WHY!!
60
40
methanol
20
water
0
0
20
40
temperature
time, minutes
60
40
methanol
20
water
0
0
20
40
tmperature
time, minutes
50
40
30
20
10
0
methanol
water
0
20
40
trmperature
time, minutes
50
40
30
20
10
0
methanol
water
0
20
time, minutes
40
14. Which of the following molecules will dissolve in water? EXPLAIN WHY!!
a.
b.
c.
d.
15. Which of the following best summarizes the relationship between dehydration reaction and
hydrolysis reactions?
a. Dehydration reactions assemble polymer and hydrolysis reactions break down polymers
b. Dehydration reactions eliminate water from lipid membranes and hydrolysis reactions make
lipid membranes water permeable
c. Hydrolysis creates monomers and dehydration reactions break down polymers
d. Dehydration reactions ionize water molecules and add hydroxyl groups to polymers while
hydrolysis reactions release hydroxyl groups from polymers
16. The enzyme amylase can break glycosidic linkages between monomers only if the monomers are in
the α form. Which of the following could amylase break down?
a. Glycogen
b. Cellulose
c. Chitin
d. Glycogen, cellulose, and chitin
17. Which of the following is true of both starch and cellulose?
a. They are both polymers of glucose
b. They are both cis/trans isomers of each other
c. They are both digested by humans
d. They are both used to store energy in plants
18. Humans can digest starch but not cellulose because
a. Starch’s monomers is glucose but cellulose’s monomer is galactose
b. Humans have enzymes that break the β glycosidic linkages of starch but not the α
glycosidic linkages of cellulose
c. Humans have enzymes that break the α glycosidic linkages of starch but not the β
glycosidic linkages of cellulose
d. Humans have starch digesting bacteria in their guts
19. Upon chemical analysis, a polypeptide is found to have 100 amino acids. How many peptide bonds
are in the polypeptide?
a. 101
b. 100
c. 99
d. 98
20. What aspects of protein structure are stabilized by hydrogen bonds?
a. Secondary
b. Tertiary
c. Quaternary
d. Secondary, tertiary, and quaternary
21. At what level of protein structure are interactions between R groups most important?
a. Secondary
b. Tertiary
c. Quaternary
d. All of them
22. What maintains the secondary structure of a protein?
a. Peptide bonds
b. Hydrogen bonds between R groups
c. Hydrogen bonds between the amino group of one amino acid and the carboxyl group of
another
d. Hydrophobic interaction
23. The tertiary structure of a protein is the
a. Unique 3D shape of a fully folded polypeptide
b. Order of amino acids in the polypeptide
c. The interactions of several polypeptides in a functional protein
d. Organization of the polypeptide into α-helices and β-sheets
24. The R group of the amino acid serine is –CH2-OH. The R group of the amino acid leucine is –
CH2-CH-(CH3)2. Where would you expect to find these amino acids in a globular protein in
aqueous solution? EXPLAIN WHY
a. Serine would be in the interior but leucine would be on the exterior
b. Leucine would be in the interior but serine would be on the exterior
c. Both serine and leucine would be in the interior
d. Both serine and leucine would be on the exterior
e. Both would be located in the interior and on the exterior
25. Changing a single amino acid in a protein consisting of 325 amino acids would
a. Alter the primary structure of the protein but not its tertiary structure of function
b. Always alter the biological activity of the protein
c. Always disrupt the primary structure of the protein and disrupt its biological function
d. Always alter the primary structure of the protein and sometimes alter the tertiary structure
of the protein and its function
26. Which of the following statements is true regarding the molecule above?
a. It is a saturated fatty acid
b. It is an unsaturated fatty acid
c. A diet rich in this molecule can contribute to atherosclerosis
d. It is a saturated fatty acid and a diet rich in this molecule can contribute to atherosclerosis
27. Which of the following statements is true regarding the molecule above?
a. It is a saturated fatty acid
b. It is an unsaturated fatty acid
c. It is an unsaturated fatty acid and is liquid at room temperature
d. It can contribute to atherosclerosis
28. Normal hemoglobin is a tetramer, consisting of 2 molecules of β-hemoglobin and 2 molecules of αhemoglobin. In sickle cell disease, as a result of a single amino acid change, the mutant
hemoglobin tetramers associate with each other and assemble into large fibers. Based on this
information alone, we can conclude that sickle-cell hemoglobin exhibits
a. Altered primary structure
b. Altered secondary structure
c. Altered primary, secondary, and tertiary structure
d. Altered primary and quaternary structure; secondary and tertiary structure may or may not
be altered
29. If cells are grown in the presence of radioactive 35S, which of the following molecules will be
labeled? EXPLAIN WHY
a. Proteins
b. Nucleic acids
c. Phospholipids
d. polysaccharides
Questions
1. What elements are found in
a. Proteins
b. Triglycerides
c. Phospholipids
d. Carbohydrates
e. Nucleic acids
2. A student wants to radioactively label ONLY the proteins in a cell. What element would best
be used in this study? Explain
3. 3. A student wished to radioactively label only the nucleic acids in a cell and she used 32-P as
her radioactive element. Did she achieve her goal? Why or why not?
4. An enzyme has the following amino acid sequence:
Met-glu-gly-ala-asp-arg-his-val-met-ile-phe-ser-arg-lys
The following 2 separate amino acid changes in the enzyme were observed:
1.
Met-glu-gly-ala-glu-arg-his-val-met-ile-phe-ser-arg-lys
2.
Met-glu-gly-ala-ala-arg-his-val-met-ile-phe-ser-arg-lys
The first amino acid change resulted in no change in the enzyme’s function, whereas the second
amino acid change did. Explain why