REF Flashcards
Is there any difference between vanillin made synthetically
and vanillin extracted from vanilla beans?
No, assuming each is pure
What important experiment was carried out by Wöhler in 1828?
A. Combining organic compounds with inorganic compound
B. Heating ammonium nitrate to form ammonia and water
C. Heating ammonium cyanate to form urea
D. carbon dioxide and water to form glucose
C
From which plant is capsaicin extracted?
Capsicum
Is cis-trans isomerism possible in alkanes?
No, alkanes restricted rotation at the double bond
When was nitroglycerin discovered? Is this substance a solid, a
liquid, or a gas?
1847, pale yellow oily liquid
Define conformation
A. A conformation is any three-dimensional arrangement of the
atoms in a molecule that results from rotation about a double
bond.
B. A conformation is any three-dimensional arrangement of the
atoms in a molecule that results from rotation about a triple
bond.
C. A conformation is any three-dimensional arrangement of the
atoms in a molecule that results from rotation about a single
bond.
D. All of these.
C
The heat of combustion of methane, the major component of
natural gas, is 213 kcal/mol. The heat of combustion of
propane, the major component of LPG or bottled gas, is 530
kcal/mol. On a kcal/mol basis, which of these two fuels is
the better source of heat energy? On a kcal/g basis, which
of these two fuels is the better source of heat energy?
A. propane, propane
B. methane, propane
C. propane, methane
D. methane, methane
C
Explain the differences in structure between a saturated hydrocarbon from an
unsaturated hydrocarbon.
A. Any of these
B. A saturated hydrocarbons contains only carbon-carbon single bonds, while
an unsaturated hydrocarbon contains one or more carbon -carbon double or
triple bonds.
C. A saturated hydrocarbon is used mainly in cheaper forms of gasoline for
vehicle use, while unsaturated hydrocarbons composed most of the
gasoline formulas, used by current gasoline manufacturers.
D. A saturated hydrocarbon can no longer accept any hydrocarbon or
inorganic element and compound, while an unsaturated hydrocarbon is
more of flexible in reaction mechanisms.
B
What is the molecular weight in amu/g /mol of 11 -tetradecenyl
acetate?
A. 382.4
B. 25.4
C. 196.2
D. 505.8
B
What different functions are performed by the rods and cones in the
eye?
A. Rods are primarily responsible for color vision. Cones are
responsible for peripheral and black-and-white vision.
B. Rods are primarily responsible for peripheral and black-and-
white vision. Cones are responsible for color vision.
C. Both are responsible for color vision.
D. Both are responsible for peripheral and black-and-white vision.
B
Which of the following objects are chiral (assume that there
is no label or other identifying mark)?
a) Pair of scissors
b) Tennis ball
c) Paper clip
d) Beaker
e) The swirl created in water as it drains out of a sink or
bathtub
A. chiral, chiral, chiral, chiral, chiral
B. achiral, chiral, chiral, achiral, chiral
C. chiral, achiral, chiral, chiral, achiral
D. chiral, achiral, achiral, achiral, chiral
D
Name the major physiologically active substances that comes from:
bark of the willow tree, the pituitary gland, the sap of the poppy
and the belladenna plant.
A. Cocaine, reserpine, salicin, atropine
B. Reserpine, atropine, B-endorphine, opium
C. Opium, cocaine, salicin, and reserpine
D. Salicin, beta-endomorphin, opium, atropine
D
Alcohols, phenols, and carboxylic acids all contain an OH
group. Which are the strongest acids? Which are the weakest
acids?
A. carboxylic acid – strongest, phenol – weaker, alcohol -
weakest
B. carboxylic acid – weaker, phenol – weakest, alcohol -
strongest
C. carboxylic acid – weakest, phenol – strongest, alcohol –
weaker
D. carboxylic acid – strongest, phenol – weakest, alcohol -
weaker
A
What is not correct about the meanings of sunblock and sunscreen?
A. A sunblock prevents all ultraviolet radiation from reaching
protected skin by reflecting it away from the skin.
B. A sunscreen prevents a portion of the ultraviolet radiation from
reaching protected skin.
C. The effectiveness of sunblock is related to its skin protection
factor (SPF).
D. None of these.
C
In the study of fats and lipids, determine which of the two
triglycerides has a higher melting point? Substance A containing
only lauric acid and glycerol, or substance B-containing only stearic
acid and glycerol?
A. Both have the same melting points
B. A
C. B
D. None of these
C
Predict the increasing order of the melting points of triglycerides
containing fatty acids, as follows:
(a) Palmitic, palmitic, stearic
(b) Oleic, stearic, palmitic
(c) Oleic, linoleic, oleic
A. a, b, c
B. c, b, a
C. a, c, b
D. b, c, a
B
Name all the groups of complex lipids that contain ceramides.
A. sphingomyelin
B. sphingolipids
C. sphingomyelin and sphingolipids
D. sphingomyelin, sphingolipids and cerebrosides
D
Which of the following is a correct statement describing the
induced-fit model of enzyme action? Substrates fit into the active
site
A. because both are exactly the same size and shape.
B. by changing their size and shape to match those
of the active site.
C. by changing the size and shape of the active site
upon binding.
D. All of these
D
What is the difference between DNA and RNA?
A. DNA has the sugar deoxyribose, while RNA has the sugar ribose.
B. RNA has uracil, while DNA has thymine.
C. All of these
D. None of these
C
In the deacetylation of acetyl histone, what is
the reactant equation?
A. Histone - (CH2) 4-NH3+ +-CH3-COOO Acetylation→ Histone –
(CH2) 4-NH-C-CH3
B. all of these
C. Histone - (CH2)4-NH3++CH3 – COO acetylation<Histone -
(CH2)4-NH-CH -> Deacetylation
D. 2 Histone- (CH2)4-NH3++4 CH3-COO -> 4 Histone- (CH2) 4-
2NHO
C
How many high-energy phosphate bonds are in the ATP molecule?
A. 1
B. 2
C. 3
D. 4
2
Glucose is the only carbohydrate compound that the brain can use
for energy. Which pathway is mobilized to supply the need of the
brain during starvation:
A. glycolysis
B. gluconeogenesis
C. glycogenesis
D. none of these
B
_______ is a rather disagreeable-smelling liquid used as a
preservative for laboratory specimens.
A. Acetaldehyde
B. Methanol
C. Methanal
D. Valeraldehyde
C
Assume that the following exothermic reaction is at equilibrium:
H2(g) = I2(g) +2HI(g)
Tell whether the position of equilibrium will shift to the right or
the left if we
(1) Remove some HI
(2) Add some I2
(3) Remove some I2
(4) Increase the temperature
(5) Add a catalyst
A. right, right, left, left, no shift
B. right, left, left, right, no shift
C. left, left, right, right, no shift
D. right, right, left, right, right
A
