Download Chemistry 100 Exam 3 Part 2

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Instructor: Nicole Stevens
Semester: Winter 2006
Chemistry 100 Exam 3
Part 1: Objective
You may write on this part of the test, but mark your final answers on a separate bubble sheet!
Consider the pictures below for questions 1-2.
A
B
C
D
1.
Which picture best represents a protein's primary structure?
a. A
d. D
b. B
e. B, C and D
c. C
f. all of the above
2.
Which structure would NOT contain hydrogen bonding?
a. A
d. D
b. B
e. B, C, and D
c. C
f. all of the above contain hydrogen bonding
3.
Which of the following is true of fats?
a. they are also called amino acids
b. they are all more dense than water
c. they have the same structure as proteins
4.
d.
e.
f.
Which of the following is NOT true of enzymes?
a. they lower the energy needed for reaction
b. they are used up in the reaction
c. they lower the temperature needed for reaction
they are all insoluble in water
they are classified by number of carbons
all of these are true of fats
d.
e.
they catalyze (speed up) reactions
all of these are true of enzymes
For questions 5-8, match each item on the left with the description on the right that best fits.
5.
Thymine
6.
Phosphate group
7.
Cytosine
8.
Deoxyribose
a.
b.
c.
d.
e.
f.
g.
h.
i.
j.
Amine base, bonds with guanine
Replaces thymine in RNA
A purine, bonds with cytosine
A fat molecule, part of the DNA backbone
Amine base, bonds with thymine
A polyatomic ion, part of the DNA backbone
A purine base that contains 2 heterocyclic rings
A pyrimidine, not present in RNA
A sugar molecule, part of the DNA backbone
A sugar molecule, part of the RNA backbone
Instructor: Nicole Stevens
2 of 9
Semester: Winter 2006
Chemistry 100 Exam 3
Part 1: Objective
You may write on this part of the test, but mark your final answers on a separate bubble sheet!
9.
Which vitamin(s) can be stored in the body for later use?
a. A and B-complex
d. B-complex and K
b. B-complex and C
e. C and E
c. B-complex and D
f. C and K
g.
h.
i.
A, D, E and K
C, D, E and K
all of the above
10. Which of the following is NOT a symptom of dehydration?
a. excess body fat
f. lack of energy
b. water retention
g. joint pain
c. migraines
h. difficulty regulating body temperature
d. build up of toxins in blood
i. stomach pain and ulcers
e. kidney damage
j. all of these are symptoms of dehydration
Consider the following label from a bag of fertilizer for questions 11-12.
11. What does the second number (3) mean in the above example?
a. # of grams of nitrogen
d. % phosphorus
b. # of grams of sulfur
e. % calcium
c. % nitrogen
f. % potassium
g.
h.
i.
# of grams of phosphorus
# of grams of potassium
can't tell from information given
12. Which of the essential plant nutrients is present in the greatest amount?
a. potassium
d. phosphorus
b. calcium
e. iodine
c. nitrogen
f. sulfur
13. In our bodies, proteins are broken down into what?
a. glucose
d. DNA
b. saturated fats
e. carbohydrates
c. unsaturated fats
f. amino acids
g.
h.
i.
fatty acids
trace minerals
whatever the body needs
14. Which of the following is a common food additive that does not increases the nutritive value of the food?
a. Vitamin C
d. iodine
b. sulfur dioxide
e. niacin
c. folic acid
f. all of these increase the nutritive value of the food
15. In our bodies, triglycerides are broken down into what?
a. glucose
d. DNA
b. vitamins
e. carbohydrates
c. fiber
f. amino acids
g.
h.
i.
fatty acids
trace minerals
whatever the body needs
3 of 9
Instructor: Nicole Stevens
Semester: Winter 2006
Chemistry 100 Exam 3
Part 1: Objective
You may write on this part of the test, but mark your final answers on a separate bubble sheet!
16. The enzyme amylase breaks down what types of things in our food?
a. carbohydrates
d. nucleic acids
b. protein
e. minerals
c. fats
f. vitamins
g. water
h. food poisons
i. any of these
Match each term below with the description that best fits it on the right.
17. Surfactant
18. Humectant
19. Exfoliant
20. Moisturizer
21. Astringent
a.
b.
c.
d.
e.
f.
g.
h.
i.
j.
inhibits bacterial growth and contamination
removes the outer layer of dead skin cells
creates lather and foam
balances the pH
stabilize a suspension of polar and non-polar molecules
blocks UV rays from entering the skin
prevents perspiration
constricts pore openings
forms a physical barrier to hinder water evaporation
holds water by hydrogen bonding
22. Which of the following is NOT true of a sunscreen or sunblock?
a. the SPF value means sun protection factor
b. sunscreens contain chemicals that absorb UV radiation before it can damage the skin cells
c. sunblocks contain chemicals that reflect UV radiation so that it isn't absorbed at all
d. wearing sunscreens and sunblocks can help prevent damage to our cells from UV radiation
e. most sunscreens primarily protect against UVC radiation because it's the most damaging
f. most sunblocks contain a metal oxide that reflects radiation
g. all of these are true of sunscreens and sunblocks
23. Which of the following cleaning products is typically acidic ?
a. oven cleaner
d. drain cleaner
b. ammonia
e. toilet bowl cleaner
c. bleach
f. soap
24. Which of the following is true of detergents?
a. an example is palm kernelate
b. leaves mineral deposits in hard water
c. causes build-up called "soap scum"
g.
h.
d.
e.
f.
all of these are acidic
none of these are acidic
contain synthetic surfactants
an example is sodium tallowate
all of these are true of detergents
4 of 9
Instructor: Nicole Stevens
Semester: Winter 2006
Chemistry 100 Exam 3
Part 1: Objective
You may write on this part of the test, but mark your final answers on a separate bubble sheet!
Mark the following statements true or false.
a.
b.
TRUE
FALSE
25. Color-safe bleach isn't a bleach at all--it is a chemical brightener that reflects blue light.
26. Depilatories are generally very acidic and work by uprooting the hair shafts.
27. Starches are polysaccharides, while sugars and cellulose are monosaccharides.
28. Regular bleach works because sodium perchlorate oxidizes colored stains into colorless products.
29. Anabolism is the process of building up molecules, and catabolism breaks molecules apart for energy.
30. During DNA replication, mRNA reads the original DNA strand, then tRNA translates the mRNA into a new
protein.
Part 1 = 45 pts.
5 of 9
Instructor: Nicole Stevens
Semester: Winter 2006
Name
Chemistry 100 Exam 3
Part 2: Write-on
Part 2 = 55 pts.
Write your answers directly on this part of the test. Please write clearly and SHOW ALL WORK!
I.
For the following DNA sequence, write the amino acid chain it would encode. Use the 3-letter
abbreviations for the amino acids, as shown in the chart in Part 1 of the exam.
4
DNA sequence: GGTTTCACCTACAATTTGATT
The mRNA sequence, in codons, would be:
CCA AAG UGG AUG UUA AAC UAA
From the chart, I would look up the amino acids that correspond to the three leter codons in the mRNA.
Amino acid sequence:
Pro - Lys - Trp - Met - Leu - Asn (stop)
II.
Fill in the blanks with the requested information, AS DISCUSSED IN CLASS:
1. Plants produce glucose and oxygen from what 2 reactants?
carbon dioxide
1 each
blank
water
2. Name 1 mineral and its role in our bodies:
Mineral:
see following list
3. Name 1 "natural" food color:
4. Name 1 food additive for increasing storage:
see following list
Role:
see following list
see following list
see following list
5. Name the 3 essential plant nutrients and their role in plant life:
Nutrient: nitrogen
Role: build
proteins
phosphorus
build, maintain RNA and DNA
potassium
fluid balance
6. List the 3 components of an RNA nucleotide.
Ribose sugar (need to say ribose!)
Phosphate group
Amine base
7. How do DNA bases bond with each other?
Hydrogen bonding
8. How do amino acids (primary protein structure) bond together?
Peptide bond (amide linkage)
6 of 9
Instructor: Nicole Stevens
Semester: Winter 2006
Name
Chemistry 100 Exam 3
Part 2: Write-on
Write your answers directly on this part of the test. Please write clearly and SHOW ALL WORK!
III.
2
For each item, discuss what chemicals they contain and how they work . You may include pictures.
a. Hair perm
Hair's natural shape (straight, curly, wavy, etc.) is determined at least in part by disulfide bonds in the hair
proteins. To perm hair, a reducing agent is placed on the hair that breaks the disulfide bonds. The hair is
arranged in a new shape (usually around rollers), then an oxidizing agent is added that will stop the
reduction and allow the disulfide bonds to re-form with the hair in the new shape.
2
b. Hair colors and bleaches
Hair is naturally colored by melanins. The more melanins in the hair, the darker the color of the hair.
Hair colors are most commonly benzene-amine compounds that soak into the hair shaft and reflect a
different color.
Hair bleaches are usually hydrogen peroxide compounds, which oxidize the natural melanins in the hair
into colorless products.
2
c. Hairspray
Hairspray is composed of semisolid organic polymers dissolved in a solvent (usually alcohol and water).
The solvent quickly evaporates, leaving the polymer which forms a sticky resin on the hair and holds
the hair in desired shape.
2
IV.
d. Hair conditioner
Conditioners commonly contain dimethicone, silk proteins and/or collagen, which smooth the cuticle
of the hair. Most conditioners work by coating the hair shaft, making it smooth and hindering evaporation
of water.
a. Soap is made from what 2 things?
fat and a base
1
b. As discussed in class, draw a soap micelle and label all parts. Explain how soap works.
Soap is a surfactant, which breaks the surface tension
(hydrogen bonding) in water, and stabilizes a suspension
of non-polar dirt and oil molecules in polar water. The
non-polar tail of a soap molecule is attracted to the nonpolar dirt/oil molecule, while the polar head of the soap
molecule remains on the surface and is attracted to the
surrounding polar water molecules. The micelle formed
allows the non-polar contaminants to remain in solution
and be carried away with the water during washing.
Water
4
3
7 of 9
Instructor: Nicole Stevens
Semester: Winter 2006
Name
Chemistry 100 Exam 3
Part 2: Write-on
Write your answers directly on this part of the test. Please write clearly and SHOW ALL WORK!
V.
You just bought a new sun protection product for your vacation to Florida.
2
a. This product has an SPF factor of 45. What percentage of the sun's UV rays does the
product protect you from? (1 decimal place)
100%
1
-
100
45
% =
97.8% protection
b. This product contains both a sunblock and a sunscreen.
1. Name an ingredient that can act as a sunscreen.
1
2. Name an ingredient that can act as a sunblock.
2
melanin
cinnamates, salicylates, PABA
Oct- compounds, benzophenone
avobenzone, octyl succinate
titanium dioxide, zinc oxide
3. Explain how sunblocks work.
Sunblocks are metals that physically reflect the UV rays, keeping them from
penetrating into the skin and causing UV damage.
4. Explain how sunscreens work.
Sunscreens are absorbed into the skin and deactivate UV rays that are absorbed
before they can damage our DNA. Some sunscreens can absorb the energy by
sending an electron to a higher energy level, then when it falls back down it
releases heat. Other molecules change configurations, then change back,
releasing vibrations. Both the heat and vibrations are harmless to our cells.
2
2
2
Discuss 2 ways your body can respond during sun exposure.
1. UV damage causes SUNBURN. Immune system is called into action to clean up dead
cells and kill cells that are too damaged to repair. Blood vessels dilate to bring more blood
to skin's surface, causing heat and redness.
2. UV causes TAN, an increase in melanin production. Melanin acts as a natural sunscreen
in our skin by changing configurations and releasing the UV energy as heat. Damage has
still been done, but less than with a sunburn.
3. Antioxidants (such as Vitamins E and C) are brought in to deactivate free radicals before
they can damage the DNA. Some are oxidized themselves, others disrupt oxidation
d. Discuss 2 ways your body can respond after sun exposure.
1. Specific immunosuppression. Some cells, after UV damage, can prevent the immune
system from killing them like it should. This can lead to cancer and further cell damage.
2. DNA repair. Cells can begin to repair damaged DNA, either by using an undamaged DNA
template (the other side of the helix) and rebuilding, or by cutting out the entire section of
damaged DNA and try to rebuild from scratch.
3. Senescence or apoptosis. If cells are beyond repair, they can go into senesence (a state of
irreversible dormancy) or apoptosis (programmed cell death). Senesence is used when the
cell is still needed for structure or spacing, and apoptosis is when cell is not needed for such.
c.
8 of 9
Instructor: Nicole Stevens
Semester: Winter 2006
Name
Chemistry 100 Exam 3
Part 2: Write-on
Write your answers directly on this part of the test. Please write clearly and SHOW ALL WORK!
VI.
2
3
1
4
1 each
blank
a. What type of object represented by the above picture?
trigylceride
b. What is represented by #1?
c.
glycerol
How are #2, #3 and #4 connected to #1?
carboxylic acid functional group
d. What is the omega- designation of #3?
Omega-7
e. What is the omega- designation of #4?
Omega-6
BONUS!!
Which of our body's fat transporters would carry the above object (represented by the picture)?
VLDL
BONUS!!
Name an essential Omega-3 fatty acid we discussed in class.
Linolenic acid, decosahexaenoic acid (DHA)
BONUS!!
Name 2 ingredients commonly found in toothpaste, as discussed in class.
fluoride, detergent (SDS, sodium laurel/laureth sulfate), abrasive, flavoring
9 of 9
Instructor: Nicole Stevens
Possible Answers for Question II.
2.
Mineral:
iodine
iron
sodium & chlorine
phosphorus
calcium
Function:
thyroid function
oxygen transport
cellular transport
energy exchange
bone health, heartbeat, coagulation
3.
Beta-carotene
saffron
annatto
turmeric
chlorella
beet juice
caramel
4.
sorbic acid
propionic acid
benzoic acid
sodium nitrite
Vitamin C (ascorbic acid)
sulfur dioxide
BHT
BHA
Semester: Winter 2006