The organelle that serves as the digestive system for the cell is the _____.
a. polysome
b. endosome
c. lysosome
d. ribosome
Which of the following vitamins has a Tolerable Upper Intake Level established?
a. thiamin
b. riboflavin
c. vitamin B6
d. vitamin B12
Which ultratrace element is not required by humans in its ionic form, but is a necessary
component of the coenzyme form of a vitamin?
a. iron
b. boron
c. cobalt
d. vanadium
The hormone whose major action is to alkalize intestinal contents by stimulating
secretion of bicarbonate from the pancreas and by inhibiting gastric acid secretion and
gastric emptying is _____.
a. gastrin
b. secretin
c. cholecystokinin
d. GRP
Nutrient-drug interactions caused by anticonvulsants such as phenobarbital used to treat
seizures 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. reduced metabolism of vitamins.
d. enhanced excretion of potassium and other electrolytes.
In which cellular site is most of the energy released when carbohydrates are oxidized to
carbon dioxide and water?
a. cytoplast
b. reticuloendothelium
c. Golgi body
d. mitochondrion
Vitamins and Energy Metabolism. Vitamins play a big role in our ability to acquire
energy from macronutrients. Pick one macronutrient and discuss how vitamins are
involved in procuring energy; choose from: (1) carbohydrates (glycolysis/ TCA); (2)
lipids (lipolysis/ β-oxidation); or (3) protein/ amino acids (gluconeogenesis). Your
answer should be as specific as possible: names of vitamins and what they do with
respect to the macronutrient you”ve chosen to help generate energy. A diagram may be
especially useful.
Hint: there are 4 vitamins for (1), 3-5 vitamins for (2), and 2-4 vitamins for (3)the
range for (2) and (3) is because it depends on the FA or AA you start with.
When the amino group has been removed from an amino acid, the carbon skeleton or
α-keto acid may be used in many different ways. Which of the following is NOT a
possible fate for the carbon skeleton?
a. conversion to glucose
b. oxidation for energy
c. production of ketone bodies
d. synthesis of creatine
Which of the following is enterohepatically circulated?
a. pancreatic enzymes
b. bile
c. glucose
d. CCK
An individual with poor vitamin A status would have a _____ RDR than someone with
a good vitamin A status.
a. greater
b. lesser
Methionine is used to synthesize S-adenosylmethionine (SAM). Why is this important?
a. so that 5-methyl THF is formed
b. so that dUMP is catalyzed to dTMP
c. so that fatty acids with an odd-numbered chain can be metabolized
d. so that methyl groups are available
Within the nucleus, all trans-retinoic acid and/or 9-cis retinoic acid binds to _____.
a. nuclear retinoic acid receptors
b. mannosylated glycoproteins
c. cell aggregates
d. transcription factors
Amino acids used primarily by muscle for synthesis of dispensable amino acids and for
protein synthesis are
a. branched-chain amino acids.
b. aromatic amino acids.
c. basic amino acids.
d. acidic amino acids.
Glucagon stimulates hepatic gluconeogenesis and suppresses glycolysis by reducing the
concentration of _____, a positive modulator of phosphofructokinase.
a. fructose-2,6-bisphosphate
b. fructose-1,6-bisphosphate
c. glucose-6-phosphate
d. glucose-1-phosphate
Most human enzymes are synthesized intracellularly and function
a. within the same cell.
b. in another location after secretion.
c. in the bloodstream due to leakage from the synthesizing cell.
d. to promote tumors unless quickly degraded.
Which of the following techniques for measuring body composition is best for
determining regional body composition?
a. hydrodensitometry
b. computerized (axial) tomography
c. total body water
d. bioelectrical impedance
Which symptom of a vitamin A deficiency is most likely responsible for
deficiency-related deaths?
a. its function as a teratogen
b. poor cellular differentiation and growth
c. keratinization of the cornea
d. severe infections
Match the category of physiological proteins with their function.
Category
1) enzymes
2) hormones
3) structural proteins
4) immunoproteins
5) transport proteins
Function
a. chemical messengers secreted by endocrine tissue and transported to target organs
where they regulate metabolic processes
b. combine with nutrients and regulate their circulation and their flow into and out of
cells
c. bind to antigens and inactivate them or cause them to be destroyed
d. catalysts that change the rate of reactions occurring in the body
e. fibrous and contractile proteins found in bone, teeth, skin, muscles, blood vessels,
hair
Which medication inhibits hydrogen release into the gastric juice, which reduces GI
mucosal irritation?
a. Pepcid
b. Nexium
c. Tums
d. Tagamet
Nutrients can be used to compensate for some gaps in our DNA. For example:
a. Individuals with a change in the base sequence for the phenylalanine hydroxylase
gene can correct the sequence of bases by eating a lot of phenylalanine.
b. Obese individuals can lose body weight by eating fewer calories than they expend.
c. Omega-3 fatty acids can up-regulate genes encoding for fat oxidation.
d. Individuals with a polymorphism that decreases activity of a folate-metabolizing
enzyme, methylene tetrahydrofolate reductase, may have more elevated plasma
homocysteine than those with a normal enzyme while more folate intake can normalize
plasma homocysteine for those with this polymorphism.
A major role for thiamin is:
a. energy transformation.
b. blood coagulation.
c. collagen formation.
d. erythrocyte synthesis.
The protein that plays a dual function in both iron and copper homeostasis is:
a. ferritin.
b. transferrin.
c. metallothionein.
d. ceruloplasmin.
What vitamin is associated with diminished proliferation and enhanced differentiation
of cells, which serves as a basis for its use as treatment of skin diseases such as
psoriasis?
a. A
b. E
c. K
d. D
Why is retinoic acid considered a hormone?
a. It has receptors on the nucleus and causes a change in protein synthesis.
b. It has a biologic function similar to insulin.
c. It is synthesized in the same tissue that it affects.
d. It causes the catabolism (break down) of body proteins.
Phospatidylinositol is a membrane phospholipid that can _____.
a. anchor surface proteins to the plasma membrane
b. create 2 second messengers in cell signaling
c. both a and b
d. none of the above
Which of the following amino acids represent the branched-chain amino acids found in
systemic circulation?
a. glycine, alanine, threonine
b. phenylalanine, tyrosine, tryptophan
c. valine, leucine, isoleucine
d. arginine, lysine, histidine
Why might someone who is drunk have high blood lactate levels?
a. High levels of NADH produced by ADH shift the direction of the lactate
dehydrogenase reaction.
b. High levels of NADH produced by the MEOS stimulate lactate dehydrogenase
activity.
c. Consuming calorie-yielding compounds and not providing enough oxygen to cells
increases anaerobic respiration.
d. Reducing equivalents inhibit the synthesis of lactic acid and increase the synthesis of
acetaldehyde.
Develop a hypothesis regarding the effects of a wide-spectrum antibiotic on the
beneficial effects of gut flora.
In response to excess dietary carbohydrate and chylomicron remnants, the liver
synthesizes _____ to transport triacylglycerol.
a. chylomicrons
b. VLDLs
c. LDLs
d. HDLs
Match the substance important for digestion with its site of production.
Molecule
1) pepsinogen
2) trypsinogen
3) ptyalin
4) digestive glycoproteins
5) cholic acid
Site of production
a. hepatocytes
b. gastric chief cells
c. pancreatic exocrine tissue
d. salivary glands
e. small intestine
When hyperventilation occurs there is:
a. an increased loss of CO2 and a decreased production of carbonic acid.
b. a decreased loss of CO2 and an increased production of carbonic acid.
Dietary fiber is currently defined as
a. carbohydrates and lignin that are nondigestible by human enzymes and are intact and
intrinsic in plants.
b. carbohydrates that are nondigestible by human enzymes, have been isolated,
extracted or manufactured, and have been shown to have beneficial physiological
effects in humans.
c. crude fiber.
d. the same as functional fiber.
Which of the physiological buffers has the most potent buffering capacity?
a. bicarbonate-carbonic acid system
b. hydrochloric acid system
c. phosphates
d. proteins
Although for micronutrients increasing the amount of a protein by directly inducing
gene expression is certainly a common mechanism, we have encountered other
mechanisms by which vitamins can regulate proteins. Pick either posttranslational
modification or allosteric regulation and provide one examplebe as specific as possible.
Consistent evidence shows that soluble fibers can lower the levels of cholesterol in
many people with high serum cholesterol. Discuss the three mechanisms by which
fibers are proposed to lower serum cholesterol.
Iron released from heme in the enterocyte is oxidized to _____ iron, which combines
with _____ and is stored as _____.
Indicate whether the statement is true or false. If the statement is false, explain why it is
false.
An increase in blood pyruvate and lactate levels may be due to a deficiency of
riboflavin.
Indicate whether the statement is true or false. If the statement is false, explain why it is
false.
Overall, assessing the status of a given mineral is difficult and requires multiple
measures.
Indicate: (1) the active form of vitamin K, (2) the general function of vitamin K, and
(3)an example of the general function (this could be a specific reaction or simply
indicate a pathway/ process where it occurs). Your answers do not need to be long!
Discuss the paradox between the benefits versus the toxic affects of arsenic.
Discuss why sucrose, ordinarily an easily digested carbohydrate, might present
problems of flatulence and diarrhea in individuals with severe inflammatory bowel
disease.
Name 4 grains that can cause severe discomfort in people with celiac disease. What are
the proteins that are problematic in each grain?
Make an argument defending the statement: To remain healthy, it is best to eat foods
containing a variety of fiber types each day.
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.GIP on the release of a hormone from the
pancreatic β-cells
Describe the process by which the cytochrome P450 system contributes to the
detoxification and metabolism of different drugs.
Three short-chain fatty acids produced by bacterial fermentation of fiber in the colon
are: _____, _____ and _____.
Briefly describe the mechanism by which increased uncoupling protein opposes storage
of energy as fat.
Several companies are now enriching enteral and parenteral nutrition products with
glutamine. What is the rationale for this procedure?
Describe the process of apoptosis in relation to the life span of the cell.
Describe the uphill-downhill concept.
Discuss the functions and significance of the folds of Kerckring, the villi, and the
microvilli.
Indicate whether the statement is true or false. If the statement is false, explain why it is
false.
Pernicious anemia can be due to folate or B12 deficiency.