Download 07-Quiz 3 Key

2
1. (22) Select (by circling) the best answer to each question below. No credit for more than one answer.
r
a. How
a.
b.
/c.
d.
are HDPE and LDPE different?
Only one of these is a member of the "Big Six."
They are made from different monomers.
One has branched chains; the other is linear.
One is made by addition polymerization, one by condensation polymerization.
V
b. This structure represents a common vitamin. From the structure, which statement about this vitamin is correct?
a. It is expected to be very soluble in fats, making an overdose possible.
b. It will playa role in metabolizing minerals in the body, making an overdose
likely.
c. It is expected to be very soluble in water, making an overdose unlikely.
d. It will be a major source of energy for the body, making an overdose
impossible.
fl)
L/'
c. Which statement is false with respect to carbohydrates?
a. They cause obesity and should be totally eliminated from a healthful diet.
b. They are metabolized in the body, producing energy.
c. They can be produced in plants by photosynthesis in an endothermic reaction.
d. Simple carbohydrates, such as monosaccharides, are made up of C, H, and 0 in a 1:2:1 ratio.
d. The
a.
b.
c.
d.
~
primary structure of proteins refers to:
the identity and sequence of the amino acids present.
the helical form that results from hydrogen bonding
the degree of aggregation of the protein units.
the folding of the chains, resulting in helices or globular forms.
e. A triglyceride is an ester of:
a. three fatty acids and a glycerol molecule.
b. a fatty acid and three glycerol molecules.
c. three fatty acids.
d. three glycerol molecules.
r
f. This is one of the coding symbols adopted by the plastics industry for packaging materials. What is the purpose of
these coding symbols?
a. to make recycling easier by making the identification of the plastics easier
b. to help manufacturers identify safety restrictions for the use of each type of plastic
c. to facilitate identification for the monomers needed to produce the polymer indicated
d. to create a code that will show how the polymer ranks in tons produced/year in the U.S.
fK
g. What do
a.
b.
c.
d.
G
PS
all minerals have in common?
They are present in your body in small amounts (<<1g).
They are non-polar
They are ions, either + or -.
They cannot hurt you if you ingest too much.
h. Complete the analogy
a. carbohydrate
b. water
/ ( ) c. disaccharide
d. glucose
e. none of the above
Amino acid:protein as
Y
i. What determines which artificial sweeteners are truly non-caloric?
a. their perceived sweetness
b. their ability to be digested
c~. if they are based on peptides or carbohydrates
their affect on rats
none of the above
~
:cellulose
3
j. Polyvinyl chloride, PVC, can exhibit many diffe::..:r..:::e-,-,n~t........'=e::.:-rties. Circle the arrangement which shows the "head-to­
head, tail-to-tail" orientation?
H H H H H H H H H H
I
I
I
I
I
I
I
I
\
I
-c-c-c-c-c-c-c-c-c-c
I
I
I
Itt
I
I
I
I
Cl Cl Cl Cl Cl Cl Cl Cl Cl CI
H H H H H H H H H H
I
I
I
I
I
I
I
I
I
I
- C - C - C - C - C - C - C - C - C - r; I
I
I
I
I
I
I
I
I
I
Cl H CI H Cl H C1 H (:1 H
H H H
I
I
I
i-l
I
H H H H H H
I
I
I
I
I
I
-(;-(;-C-C-C-C-G-C-C-C­
I
I
I
Cl H H
I
I
('1 H
I
I
I
I
r
CI CI H (;1 H
k. Which statement concerning the studies on caloric restriction we discussed in class is invalid?
a. The rats in the study group were malnourished.
b. The biosphere supports the theory that caloric restriction improves health.
~c Studies are underway with primates but take longer to complete than the studies with rats .
• '\ jd. The rats in the study group lived longer but in general experienced poorer health.
2. (8) a. Explain the dietary risk of not consuming complete protein and how someone who consumed no complete
protein could still live a healthy life.
b. In his song Thrasher, Musician/songwriter Neil Young said, "Me, I'd had enough. Burned my credit card for fuel.
Headed out where the pavement turns to sand." Could this have happened based on what we have covered In
class?
3. (9) Use your understanding of chemistry to explain why:
a Crosslinks stiffen a polymer
b. We can digest potatoes but not grass.
c.
Eggs turn white/opaque when cooked
)
4
4. (15)
3 different ways to
denature a protein.
3 ways to indicate
mono- and di­
saccharide content
In food labels, in
addition to suqar
3 different ways to
change the
properties of
polymers
3 advantages of food
irradiation
3 ways to handle
used plastics
NoJ
CLcid
~
CCJVV\~('Uf
fylJ.L+-O~
0{C£:b \l ~S
Pv~v:)
r¥\fJV\t5YvUx ~
t
~+
¢t~~ t fYlJ-P l,t-e.­
~<?-h',",~ ~
b1'ode~aJ~ lY
\{\U" NXafe,
re.U1V\e,
-
'Go­
5. (10) Both unsaturated fats and polymers can display cis/trans isomers.
atoms are on the same side, while
product of
t. (S
_+Va..t\S means they are on opposite sides.
~ reactions, in which carbon-carbon
The shape of a molecule is very important.
~z-y~
starting material of reactions they catalyze according to the
these reactions are sometimes called
enzymes need a
~~C~ to work properly.
means that groups of
bonds are replaced by
~ &U
melting point.
must have shapes complimentary to the
~ and ~ model.
'5U JofJ+raro
:::!C
Trans fats are the undesired
clcu..Me..
hydrogen atoms. This changes the shape of the molecule and causes it to have a
~
The reactants in
In addition to the proper 2°/3° structure, some
Vitamins and minerals often play this role, "turning on" the
protein catalysts.
6. (11) Explain all the scientific and economic aspects that must be considered when choosing "paper or plastic" at
the grocery store, focusing on how you arrive at your personal decision.