In the enzyme methionine synthase, vitamin B12 acts by accepting a _____ group from
_____ and donating this group to _____ to form methionine.
a. carbon, methionine, folate
b. methyl, 5-methyltetrahydrofolate, homocysteine
c. methyl, formiminoglutamic acid, succinyl-CoA
d. carbon, serine, glycine
Anticoagulant drugs that act by inhibiting vitamin K activity do so by which
mechanism?
a. inhibiting the formation of the active form of vitamin K
b. interfering with micelle formation so vitamin K is not absorbed
c. not allowing calcium to interact with Gla residues
d. stimulating osteocalcin synthesis
Which of the following is NOT a neurotransmitter?
a. acetylcholine
b. serotonin
c. insulin
d. epinephrine
Choose the non-genomic effect of vitamin D.
a. increased synthesis of calbindin
b. bone accretion
c. rapid calcium absorption
d. intracellular cytosolic signal transduction
Which of the following is NOT transported by the vascular system?
a. regulatory hormonal messages from the endocrine system
b. oxygen from the respiratory system
c. regulatory neural messages from the nervous system
d. organic nutrients and minerals from the digestive system
The product(s) of pepsin’s action is/are _____.
a. disaccharides
b. amylose
c. short-chain fatty acids
d. hydrolyzed proteins
For the specified conditions given in the table below, indicate if the components shown
will increase (I) or decrease (D) immediately following the event and before
homeostatic mechanisms return levels to normal.
For active transport (e.g., of glucose), you need:
a. ATP.
b. a Na-K pump.
c. Na.
d. an integral protein.
e. all of the above
Urea synthesis occurs partly in the mitochondria and partly in the cytosol of the _____.
a. glomeruli
b. tubules
c. enterocytes
d. hepatocytes
What are the homopolymers of glucopyranose found in cereal brans such as oats and
barley that are effective in reducing serum cholesterol?
a. beta-glucans
b. fructans
c. fructooligosaccharides
d. chitin
Which ultratrace element was used as a preservative for meat, fish, and dairy products
in the early 1900s, considered dangerous for humans in the 1920s, and then deemed
essential starting in the 1980s?
a. cobalt
b. arsenic
c. boron
d. vanadium
Triacylglycerols with saturated fatty acids of longer chain length tend to be _____ at
room temperature.
a. liquid oils
b. emulsified
c. non-esterified fats
d. solid fats
What is the condition that occurs in starvation or diabetes in which there is an increase
in the urinary excretion of ammonia?
a. metabolic alkalosis
b. metabolic acidosis
During the end reaction of the electron transport chain, molecular oxygen becomes
_____.
a. oxidized to carbon dioxide
b. reduced to water
c. NADH + H+
d. FADH2
The enzyme ATP synthase is believed to catalyze the formation of ATP, as described by
the _____ theory.
a. leakage
b. hydrogen pump
c. protein channel
d. chemiosmotic
A number of metabolic pathways have a problem in that certain components required
for them to function are found in either the cytosol or the mitochondria, and some
intermediates cannot cross the membrane. This requires that certain compounds be
shuttled from one compartment to the other. Explain this shuttling process for either: (a)
glycolysis/TCA cycle OR (b) gluconeogenesis. Your answer should include: what needs
to be shuttled, why it needs to be shuttled, and how this is accomplished.
Match the regulatory hormones with their primary functions in integrative metabolism.
Hormones
1) GI hormones
2) insulin
3) epinephrine
4) glucagon
5) glucocorticoids
Primary Functions
a. stimulates liver glycogenolysis and gluconeogenesis
b. amplify the response of pancreatic beta-cells to glucose
c. stimulate gluconeogenesis by acting on the muscle to enhance release of alanine
d. stimulates removal of glucose from the blood and anabolic reactions
e. primarily stimulates muscle glycogenolysis
Which of the carotenoid pigments has the greatest vitamin A activity?
a. alpha-carotene
b. beta-carotene
c. gamma-carotene
d. delta-carotene
When diagnosing lactose intolerance, _____ is measured in the breath following oral
consumption of 50 g lactose.
a. methane
b. hydrogen
c. carbon dioxide
d. sulfur
Iron content of the average Western diet is estimated to be about
a. 1 to 4 mg iron per 1,000 kcal.
b. 5 to 7 mg iron per 1,000 kcal.
c. 8 to 15 mg/day.
d. 18 g /day.
If someone consumes a high-protein diet to meet energy needs, he/she will use _____
oxygen relative to the amount of CO2 he/she is generating (Hint: think RQ).
a. less
b. more
c. equal
d. not enough information
Which of the microminerals is considered essential for normal brain function?
a. chromium
b. fluorine
c. vanadium
d. manganese
How long does it take for the postabsorptive state to evolve into the fasting state?
a. 12-18 hours
b. 24-36 hours
c. 18-48 hours
d. 36-72 hours
Thromboxane A2 is a hormone-like substance made from:
a. stearic acid.
b. arachidonic acid.
c. palmitic acid.
d. myristic acid.
A genetic polymorphism that decreases the activity of N5,N10 methylene
tetrahydrofolate reductase has been identified. This would cause _____.
a. an accumulation of 5-methyl THF
b. an increase in the homocysteine concentration in the cell
c. a decreased risk for megaloblastic anemia
d. a decreased risk for heart disease
The use of prebiotics for blood glucose regulation:
a. is not currently recommended.
b. is recommended for those with prediabetes but not diabetes.
c. has been proposed but not investigated through research.
d. is more effective than the use of other dietary fibers.
Which mineral may substitute for magnesium in the complement system?
a. boron
b. cobalt
c. silicon
d. nickel
Nutrient-drug interactions caused by antacids used to treat GERD are most likely to
result in
a. poor absorption of nutrients such as iron.
b. poor absorption of the drug when taken with grapefruit.
c. enhanced metabolism of the drug rendering it less effective when taken on an empty
stomach.
d. enhanced excretion of potassium and other electrolytes.
Excessive intake of non-heme iron interferes with absorption of which mineral by an
unknown mechanism?
a. manganese
b. zinc
c. chromium
d. selenium
True/False
The various components within a cell (e.g., mitochondria) are not “free-floating” in the
cytosol, but rather are held in place by the cytoskeleton.
Ascorbic acid provides a reducing equivalent so that iron is in the _____ form in lysyl
hydroxylase.
a. ferric
b. ferrous
Discuss the role of drug therapies such as Tagamet, Zantac, and Pepcid in the treatment
of peptic ulcers.
Discuss the role of HDL in counteracting risk by modifying plaque formation.
Indicate whether the statement is true or false. If the statement is false, explain why it is
false.
During fasting conditions, glucagon induces phosphoenolpyruvate carboxykinase
(PEPCK) and glucose 6-phosphatase as a means to increase gluconeogenesis in
muscles.
Glycogenesis, glycogenolysis, gluconeogenesis, and glycolysis are tissue-specificthat
is, either the pathway or certain aspects of the pathway are different for different
tissues. Pick ONE metabolic process and describe what occurs, including what tissues
are involved and any tissue-specific differences. Make sure to indicate any and all
signals involved in this process.
Indicate whether the statement is true or false. If the statement is false, explain why it is
false.
Zinc fingers are involved in gene expression by playing a structural role in nuclear
binding proteins such as RAR; thus, RAR is a metalloenzyme.
Alcohol consumption increases the NADH/NAD+ ratiothat is, alcohol metabolism
results in an increase of NADH and a depletion of NAD+. In terms of changes in
enzyme activities, describe how alcohol consumption via the change in the
NADH/NAD+ ratio decreases the oxidation of carbohydrates.
Indicate whether the statements is true or false. If the statement is false, explain why it
is false.
Magnetic resonance imaging, a method for assessing body composition, involves the
use of isotopes such as deuterium, radioactive tritium, or oxygen-18.
Sketch the Krebs cycle beginning with glycogen and show where various vitamin
cofactors act in energy metabolism.
List 5 dietary factors that influence iron absorption and indicate what each factor does.
Explain how the HMG-CoA reductase regulates cholesterol synthesis.
Neural and hormonal events affect the activities of the GI tract. These can be classified
as stimulatory or inhibitory. For questions 56-62, choose “a” if the action described is
stimulatory and “b” if it is inhibitory.Secretin on HCl release
Lipoprotein Transport. List the four lipoproteins below and provide a BRIEF
explanation of their function with respect to transportation of lipids and lipid-soluble
compoundsyour answer should include the tissue of origin, what they transport, and
what they do with their cargo.
Indicate whether the statement is true or false. If the statement is false, explain why it is
false.
Biotin and B12 are both required for the synthesis of odd-chain fatty acids.
The anion gap is a clinically useful parameter for identifying metabolic disorders that
affect electrolyte balance. How is it calculated?
In anaerobic conditions the NADH produced in glycolysis is not reoxidized by oxygen
in the mitochondria but is oxidized to NAD in the cytoplasm by an enzyme. What is the
enzyme and what is the importance of this reaction for conditions of low oxygen level?
Changes in hormone balance serve as the primary mechanism for adjustment to
starvation. What changes occur and how do they facilitate adjustment to starvation?
When dietary intake of carbohydrate is reduced or blood glucose concentration
declines, the pathway that is stimulated in the liver by glucagon and corticosteroids is
called _____. Four non-carbohydrate precursors that serve as substrates for this
pathway are: _____, _____, _____ and amino acids.