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FSHN 101: Introduction to Food Science and Human Nutrition
Hour Exam II: Food Chemistry and Composition
Fall Semester 2009: Friday, October 16, 2009
Description: This is an exam over what you have learned during the second section of the course. The results of
this test will aid you in clarifying any points of difficulty and thus, help you complete the course successfully.
Instructions: Please use the computer answer form provided to record your answers to the questions below. The
multiple-choice questions should be answered using the first four bubbles per row (A, B, C or D). The TrueFalse questions should be answered using the first two bubbles per row (A or B). Please use only a No. 2 pencil
to record your answers and be certain to completely fill the bubble with the pencil mark. Each of the 40
questions is worth 2.5 points for a total of 100 points.
A. Multiple Choice 1 Carbon14 is an isotope of the element Carbon, which means that it possesses a different number
of _________, but the same number of _________ and _________.
d. 2 To satisfy the octet rule, Hydrogen (element H) shares its outer shell electron with Chlorine
(element Cl), resulting in hydrogen chloride (HCl). This type of bond is called a(n):
d. 3 protons; electrons; nucleus
electrons; nucleus; neutrons
neutrons; protons; electrons
electrons; protons; neutrons covalent bond
dipole-dipole bond Which of the following foods is composed of three phases of matter:
d. carbonated soda
still bottled water
orange juice with pulp
whipped cream 4 The chemical functional group illustrated below is called a (or an) ________ and is important in
________. a. ester; aromas (i.e. flavors) and lipids
b. carboxylic acid; proteins and lipids
c. ketone; aromas (i.e. flavors) and carbohydrates
d. amide; proteins
5 Due to the fact that water is composed of 2 partially positive Hydrogen atom(s) and 1 partially
negative Oxygen atom(s), water can hydrogen bond with _________ other water molecule(s).
d. 6 1
4 Using the phase diagram for pure water, identify the approximate boiling point of water at a
pressure of 20 atm (see black arrow for help)? a. 312°C
d. 374°C 7 ________ heat is added when solid water to melts into liquid water at 0ºC. In order for 1 gram
of liquid water to go from 20°C to 50°C, the addition of ________ heat is required.
a. sensible; more sensible
b. dormant; rational
c. latent; sensible
d. sensible, latent 8 A batch of Combos® accidentally slipped through quality control before being evaluated for
water activity (Aw). Due to a production error, the Aw of the cracker portion of the Combos®
was ~0.3 and the Aw of the cheese in the center of the Combos® was ~0.6. Considering these Aw
values and the fact that the Combos® are placed together in a sealed container, which of the
following events will occur over time?
a. The moisture content of both products will become equal.
b. The moisture content of both products will increase.
c. The relative humidity of the air space in the container will decrease.
d. The Aw o f both products will become equal. 9 Which of the following products possesses the least favorable conditions for microbial growth:
d. 10 ________ is a disaccharide found in ________ that is composed of ________ and ________.
d. 11 Lactose; milk; glucose and glucose
Sucrose; milk; glucose and fructose
Lactose; sugar beets; glucose and fructose
Sucrose; sugar beets; glucose and fructose Which of the following is never a functional property of simple carbohydrates:
d. 12 cheese at 40% moisture content and a 0.97 Aw
bread at 36% moisture content and a 0.96 Aw
Spam® at 40% moisture content and a 0.83 Aw
jam at 33% moisture content and a 0.86 Aw They provide texture to foods
They provide viscosity to liquids
They increase water activity (Aw)
They participate in browning reactions ________ is an alternative sweetener that is often paired with aspartame in beverages, yet does
not contribute any calories to the beverages (unlike aspartame).
Neotame 13 ________ is a complex carbohydrate that contains -1,4 linkages and is typically considered a
straight chain molecule.
d. 14 You decide to make yourself some homemade pudding. You make the pudding according to
the directions and cannot wait to enjoy it when it¶s ready. After you put it in the refrigerator,
your friend calls and asks you to go to dinner. Of course you accept, forgetting about the
pudding entirely. In fact, you don¶t remember the pudding until five days later, at which point
the pudding has ³cracked´ and there is water seeping out of it. This phenomena is called:
d. 15 Amylopectin
Dietary fiber gelatinization
viscosity Which of the following statements regarding dietary fiber consumed by humans is true:
a. Fiber is always insoluble in water.
b. Only insoluble fiber is needed in the diet.
c. Insoluble fiber cannot be metabolized by bacteria in the large intestine, but it is still
required in our diet.
d. In terms of chemical classification, fiber is in its own separate category. 16 Which functional group in amino acids gives each amino acid its unique identity and chemical
d. 17 At _________, an amino acid possesses as many hydrogens as it can possess, resulting in
positive charges on amine groups and neutral charges on carboxyl groups.
d. 18 the alpha carbon
the carboxyl group
the amine group
the ³R´ group acidic pH (pH < 7)
neutral pH (pH = 7)
basic pH (pH > 7)
the isoelectric point Which of the following is not characteristic in peptide bond formation:
d. Peptide bonds result from condensation reactions.
Covalent bonds comprise peptide bonds.
Two ³R´ groups of two amino acids combine to form a peptide bond.
The carboxyl group of one amino acid and the amine group of another amino acid form a
peptide bond. 19 The ³long distance´ folding of the polypeptide chain that can result once -helices, -pleated
sheets, and random coils are formed is known as the ________ structure of a protein.
d. 20 primary
quaternary You were making a cream based sauce for your pasta and decided to add some freshly canned
tomatoes to the sauce. It tasted fine, but the cream started to curdle. What happened to the
a. The milk proteins in the cream acted as an emulsifier between the moisture in the tomatoes
and the lipids in the cream.
b. Gelation occurred between the milk proteins in the cream and the pectin in the tomatoes.
c. The milk proteins in the cream were denatured by the acid in the tomatoes.
d. The tomatoes changed the primary structure of the milk proteins in the cream. 21 ________ is/are used to cleave proteins at the primary structure, which can soften tough cuts of
meat and clarify American-style lager beers.
d. 22 ________ can be utilized in a desirable manner, for example to clarify fruit juices, or may be
undesirable, causing structural damage in fruits and vegetables.
d. 23 Lipases
Pectinases The lipid pictured below is classified as ________.
a. a triglyceride
b. a saturated fatty acid
c. a monounsaturated fatty acid
d. a polyunsaturated fatty acid 24 The omega notation for a fatty acid is 16:2w-6, 9. What is the corresponding delta notation for
this fatty acid?
b. 16:2d-7, 10
c. 16:2d-3, 6
d. 16:2d-9, 12 25 The table below gives the percent (%) fatty acid composition of 3 lipids (identified as 1, 2, and
3). Which of the following statements is true regarding the physical state of these lipids? Lipid Palmitic
(18:0) Oleic (18:1d9) Linoleic (18:2d-9,
12) 1 32.4 20.8 10.2 14.8 2 11.3 9.8 44.8 22.6 3 23.9 28.2 16.4 15.7 a. Lipids 1 and 3 are classified as fats, whereas lipid 2 is classified as an oil.
b. Lipids 1, 2, and 3 are classified as oils.
c. Lipids 2 and 3 are classified as fats, whereas lipids 1 is classified as an oil.
d. Lipid 2 is classified as a fat, whereas lipids 1 and 3 are classified as oils.
26 ³Trans´ is an adjective used to describe a fatty acid¶s:
d. degree of saturation
absorption B. True/False 27 Functional groups are specific groups of elements within molecules that are responsible for the
chemical behavior of that molecule. 28 Solid water (ice) is less dense than liquid water due to the fact that the molecules in solid water
are more mobile than the molecules in liquid water. 29 A friend who lives in New Orleans, LA, where the atmospheric pressure is greater than the
atmospheric pressure in Champaign, IL, gave you a recipe for brownies. If you want to bake
the brownies in Champaign, you will need to increase the baking temperature and cook the
cake for a shorter period of time. 30 A saturated sugar solution is defined as the maximum amount of sugar that can dissolve in a
given amount of water at a specific temperature. 31 High fructose corn syrup, made using the enzyme glucose isomerase, and invert sugar syrup,
made using the enzyme invertase, are composed of the same chemical compounds, and thus,
our bodies recognize them similarly. 32 Alitame, like aspartame, is chemically composed of two amino acids, and thus, is 4 kcals/gram. 33 Although native starch granules from different plants vary in size and shape, they do not vary
in composition. 34 Soluble fibers, like xanthan gum and pectin, are used in food systems to give highly viscous
solutions at low concentrations. 35 Protein gelation involves the swelling of the protein molecule in the presence of heat. 36 During extrusion cooking, an increase in pressure in the extruder assembly results in an
increase in temperature, providing enough heat to allow the gelatinization of starch and
denaturation of protein. 37 Proteins and triglycerides are formed in condensation reactions, meaning that water is
absorbed when the larger molecules are formed. 38 Enzymes are proteins that increase the temperature of a reaction. 39 Because butter and margarine are both 80% lipid, they provide equal kilocalories per gram. 40 A fatty acid with the structural notation 22:2 will have a higher melting point than a fatty acid
with the structural notation 18:0. ...
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This note was uploaded on 02/18/2012 for the course ECE 333 taught by Professor Overby during the Spring '09 term at University of Illinois, Urbana Champaign.
- Spring '09