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MATCHING
Classification
1) oxidoreductases
2) hydrolases
3) transferases
4) lyases
5) ligases
Examples
a. Enzymes that catalyze cleavage of C-C, C-S, and certain C-N bonds (excluding
peptide bonds) without hydrolysis or oxidation-reduction
b. Enzymes forming bonds between carbon and other atoms, such as acetyl-CoA
carboxylase, which adds bicarbonate to acetyl-CoA to initiate fatty acid synthesis in the
cytoplast
c. Enzymes in the election transport chain in the mitochondria
d. Enzymes that catalyze cleavage of bonds by addition of water, such as digestive
enzymes
e. Enzymes that catalyze reactions, not oxidation or reduction, in which a functional
group is moved from one substrate to another, such as transaminase
True/False
The reason we require the malate-aspartate shuttle is because NADH cannot enter the
mitochondria to donate its electrons to the electron transport chain.
True/False
The reason we require the malate-aspartate shuttle is because NADH cannot enter the
mitochondria to donate its electrons to the electron transport chain.
7. In general, most amino acids are absorbed from the
a. stomach.
b. duodenum and jejunum.
c. ileum.
d. colon.
The richest dietary sources of vanadium are _____.
a. fats and oils
b. cereal and grain products
c. sweeteners
d. milk products
Indicate whether the statement is true or false. If the statement is false, explain why it is
false.
The primary role of vitamin C is as a reducing agent, particularly for the mineral
component of a number of enzymes that becomes oxidized following catalysis of a
reaction.
In addition to protein synthesis, the brain uses amino acids for the synthesis of other
N-containing compounds such as neurotransmitters.
Indicate whether the statement is true or false. If the statement is false, explain why it is
false.
Acetyl-CoA is a branch point for a number of metabolic processes, including
metabolism of carbohydrate, lipid, and cholesterol.
True/False
The Cori cycle would be active under anaerobic conditions, such as excessive muscle
exertion.
True/False
Although many enzymes in a given pathway are bidirectional, often the key enzymes
are unidirectional (i.e., only work in one direction).
Indicate whether the statement is true or false. If the statement is false, explain why it is
false.
In the folate-dependent one-carbon pool, a carbon unit in the methyl form (i.e.,
5-methyl THF) is used in the conversion of homocysteine to methionine, whereas a
carbon unit in the methylene form (i.e., 5,10-methylene THF) is used in DNA synthesis.
Indicate whether the statement is true or false. If the statement is false, explain why it is
false.
Pellagra symptoms may appear during B6 deficiency, because this vitamin is required in
the process of obtaining niacin from tryptophan.
True/False
Most Americans consume approximately half of their total dietary lipid as
triacylglycerols, and the other half as cholesterol; very little is taken in as
phospholipids.
Indicate whether the statement is true or false. If the statement is false, explain why it is
false.
Zinc deficiency could result in a secondary deficiency of folate, because polyglutamate
hydrolase is a zinc-containing enzyme.
True/False
Adipocytes' primary function is to store fat as triacylglycerol; thus, they do not require
glycolysis and the TCA cycle for energy needs.
Indicate whether the statement is true or false. If the statement is false, explain why it is
false.
The reason we use equivalents when discussing the RDA for some vitamins is that there
are different forms of the vitamin that, by weight, are not equal in terms of vitamin
activitythis is due to differences in absorption and/or metabolism.
True/False
The process of gluconeogenesis occurs partially in the mitochondria, and partially in the
cytosol.
Indicate whether the statement is true or false. If the statement is false, explain why it is
false.
Many anticoagulants work by inhibiting the regeneration of active vitamin K (i.e.,
dihydrovitamin KH2) during the vitamin K cycle.
Indicate whether the statement is true or false. If the statement is false, explain why it is
false.
Endocytosis is the mechanism for a transferrin receptor transporting iron into a cell.
True/False
Unlike long-chain fatty acids, short-chain fatty acids from the diet leave the enterocyte
via the portal vein and go directly to the liver.
True/False
The purpose of the pentose phosphate pathway is to generate ribose, for nucleic acid
synthesis, and NAD, for oxidizing power.
Indicate whether the statements is true or false. If the statement is false, explain why it
is false.
The term lean body mass allows for the presence of a small amount of essential fat
required for physiological functioning.
True/False
Dietary proteins must be completely hydrolyzed to free amino acids, because only free
amino acids are absorbed by the enterocyte.
The amino acid profile of the blood is relatively constant.
True/False
The muscle is an important tissue in gluconeogenesis, because it can use amino acids
from protein breakdown and convert them to glucose, which it then secretes into the
circulation for other tissues.
Indicate whether the statement is true or false. If the statement is false, explain why it is
false.
Rhodopsin is simply the opsin protein after it has been activated by 11-cis-retinal.
Indicate whether the statement is true or false. If the statement is false, explain why it is
false.
Copper deficiency can result in iron deficiency due to an inability to oxidize iron (i.e.,
Fe+++), required for transport by transferring.
True/False
Glucose is transported from the lumen into the enterocyte by active transport using
SGLT1 protein, which also requires Na as a co-transporter.
True/False
When BCAAs are catabolized to their corresponding keto acid in muscle, the nitrogen
must be transported directly to the kidney as glutamine.
True/False
The key organ in clearing (i.e., breaking down) lipoproteins is the liver.
True/False
All cells have mitochondria, which act as the main site for ATP production.
True/False
Once a micelle, containing lipids and lipid-soluble compounds, enters the enterocyte, it
is referred to as a chylomicron.
Indicate whether the statement is true or false. If the statement is false, explain why it is
false.
Calcium homeostasis in the blood depends on intestinal absorption, bone resorption,
and kidney reabsorption.
True/False
When discussing enzyme kinetics, Km refers to the substrate concentration at which the
enzyme is saturated and functioning at maximal velocity.
Indicate whether the statement is true or false. If the statement is false, explain why it is
false.
Vitamin D increases the abundance of calbindin (Ca++ transporter) in enterocytes by
increasing the transcription of the calbindin gene.
True/False
Essential fatty acids are classified as such because we cannot synthesize them from
other fatty acids and they are required for the synthesis of prostaglandins,
thromboxanes, and leukotrienes.
Indicate whether the statement is true or false. If the statement is false, explain why it is
false.
Glucagon and insulin control metabolic pathways that reflect a fasting and fed state,
respectively; the primary signal to initiate this hormonal control is the glucose
concentration in the bloodstream.
True/False
Because they do not have mitochondria, red blood cells generate a lot of lactate from
glycolysis, which they in turn must convert into glucose to meet their energy needs.
Indicate whether the statement is true or false. If the statement is false, explain why it is
false.
Circulating concentrations of a vitamin typically reflect diet, whereas intracellular (e.g.,
RBCs, leukocytes) concentrations reflect body pools.
Indicate whether the statement is true or false. If the statement is false, explain why it is
false.
The three major systems involved in metabolic integration are the (1)nervous,
(2)endocrine, and (3)vascular systems.
Indicate whether the statement is true or false. If the statement is false, explain why it is
false.
Albumin carries zinc and copper in the portal circulation to all tissues in the body.
What is the name of the digestive enzyme in saliva that digests starch?
a. lipase
b. synthetase
c. amylase
d. lactase
Which vitamin has a reduced coenzyme form important for fatty acid and cholesterol
synthesis that is a product of the pentose phosphate pathway?
a. niacin
b. thiamin
c. riboflavin
d. vitamin C
The organelle responsible for production of most of the metabolic energy (ATP) is the
_____.
a. Golgi apparatus
b. endoplasmic reticulum
c. nucleus
d. mitochondrion
Name the model that depicts cyclized monosaccharides as lying in a horizontal plane
with the hydroxyl groups pointing down or up from the plane.
a. Haworth
b. Fischer projection
c. cyclized Fischer projection
d. stereoisomer
One of the major molecules absorbed from the colon is water and one liter of chyme
entering the large intestine is normally reduced to _____.
a. 500 g
b. 400 g
c. 300 g
d. 200 g
In what type of tissue is the largest amount of vitamin E stored?
a. adipose
b. heart
c. lung
d. brain
Which three vitamins are involved in the synthesis of fatty acids?
a. biotin, vitamin D, thiamin
b. thiamin, riboflavin, niacin
c. niacin, biotin, pantothenic acid
d. riboflavin, B12, folate
We discussed three (3) systems that play a role in supplying energy during movement/
exercise. Name these three systems, describe briefly how they supply energy, and
discuss the temporal relationship between them during prolonged exercise. Any figures
should be completely labeled and explained.
Which categories of food provide the most nickel?
a. red meats
b. nuts, legumes, grains
c. fish
d. milk and milk products
When superoxide radicals accumulate, superoxide dismutase catalyzes the formation of
hydrogen peroxide. What happens to the hydrogen peroxide?
a. It freely dissociates to water.
b. It is excreted in the urine and through the lungs.
c. It is converted to water and oxygen via catalase or glutathione peroxidase.
d. It is used in the synthesis of DNA and RNA.
Electron flow through Complexes I, III, and IV is accompanied by the translocation of
protons
a. from the matrix into the intermembrane space.
b. from the iron-sulfur centers into the cytosol.
c. from cytochrome c to cytochrome c1.
d. from cytochrome b to the iron-sulfur center.
Choose the phrase that best describes the function of the crypt of Lieberkhn.
a. mucus secretion
b. glucose oxidation
c. cellular differentiation
d. amylase secretion
Which micromineral is necessary for iodine metabolism?
a. fluorine
b. manganese
c. chromium
d. selenium
Statistically, what percentage of individuals with anorexia nervosa recover completely?
a. about 50%
b. about 30%
c. about 25%
d. about 15%
Prebiotics act as substrates for the growth of beneficial bacteria in the colon and are
_____.
a. certain types of bifidobacteria
b. live cultures of mixed lactobacilli
c. selected fibers
d. antibiotics
Which of the water-soluble vitamins is able to be stored and retained in the body for
long periods of time?
a. folic acid
b. niacin
c. thiamin
d. B12
Zinc is important for taste perception as a component of _____.
a. carbonic anhydrase
b. alcohol dehydrogenase
c. gustin
d. thionein
Anaerobic bacteria populate the gut in _____ greater quantities than aerobic bacteria.
a. 2 fold
b. 5 fold
c. 10 fold
d. 100 fold
What is the current Tolerable Upper Intake Level established for protein and amino
acids?
a. Ingestion of a diet supplying > 30% energy from protein
b. Two times the RDA
c. 42 mg/kg/d
d. No Tolerable Upper Intake Level has been established.
Significant loss of what mineral occurs when one exercises vigorously while the
temperature is high?
a. sulphur
b. phosphorus
c. sodium
d. potassium
Because of its anti-inflammatory actions, which element may reduce the severity of
rheumatoid arthritis?
a. cobalt
b. boron
c. silicon
d. arsenic
Which is the best measure of vitamin K status?
a. des-γ-carboxyglutamic prothrombin
b. prothrombin time
c. INR
d. PTH concentration
Which of the following conditions is attributed to a primary failure of the β-cells of the
pancreas to secrete insulin?
a. hyperinsulinism
b. hyperglycemia
c. hyperlipidemia
d. hyperphosphatemia
What is a likely reason that large quantities of fructose may cause gut discomfort?
a. Diffusion of fructose only occurs from low to high concentrations.
b. Facilitated diffusion is slower than active transport.
c. Active transport is saturable.
d. Pinocytosis reverses fructose and releases it to the gut.
A function of hydrochloric acid in the gastric juice is to
a. digest protein, functioning as an endopeptidase.
b. protect the stomach lining from damage.
c. inhibit secretion of gastrin and CCK.
d. act as a bactericide agent.
In the presence of low intracellular iron, the binding of iron regulatory protein
(IRE-BP) to iron response elements (IRE) present on the ferritin mRNA:
a. results in a decrease in ferritin abundance.
b. results in an increase in ferritin abundance.
c. occurs only when intracellular iron concentrations are high.
d. doesn"t occur.
A ketopentose is a carbohydrate containing
a. 5 carbons and a ketone group.
b. 6 carbons and an aldehyde group.
c. 3 carbons and an aldehyde group.
d. 7 carbons and a ketone group.
Use the molecules below to answer.
Which is β-carotene?
a. A
b. B
c. C
d. D
e. E
Match each hormone or enzyme with its site of production and function in regulating
fluid and electrolyte balance.
Hormone/Enzyme
1) vasopressin
2) aldosterone
3) renin
4) angiotensin II
5) atrial natriuretic peptide (ANP)
Production Site and Function
a. Hormone produced in atrial cells of the heart; functions to inhibit sodium
reabsorption in the kidney, thereby promoting fluid loss.
b. Hormone produced in hypothalamus; functions to conserve water by increasing
reabsorption of water by the kidneys.
c. Hormone produced in adrenal cortex; functions to stimulate active reabsorption of
sodium by the kidneys, thereby promoting fluid retention. d. Enzyme produced by
kidney; functions to hydrolyze angiotensinogen to angiotensin I.
e. Active hormone produced by angiotensin-converting enzyme in the lungs; functions
as vasoconstrictor, as stimulator for release of aldosterone, and as stimulator of
hypothalamus to release vasopressin.
What type of cell depends solely on energy produced through anaerobic mechanisms?
a. hepatocyte
b. enterocyte
c. glucocyte
d. erythrocyte
What are the components that make up non-fermentable dietary fiber and in what foods
are each found?
The absorbed carotenoids that enter the liver can follow three routes: _____, _____ and
_____.
What is meant by protein turnover? What general types of protein compounds are made
in cells via protein synthesis? How do amino acid catabolism and dietary amino acids
factor into protein turnover?
Indicate whether the statement is true or false. If the statement is false, explain why it is
false.
Muscle supplies its own glucose for energy needs by first using glycogen stores, and
then converting amino acids into glucose.
Describe the mechanisms by which resin-type drugs and functional foods containing
phytostanols lower high blood cholesterol levels.
Explain why serum levels of ALT and AST are good indicators for trauma or disease,
and specify which tissues relate to which aminotransferase.
Often you will hear the statement, "Insulin is important for the uptake of blood glucose
by all tissues." What is wrong with this statement? Be specific.
Glucokinase located in the _____ is induced by insulin, and hexokinase located in the
_____ is inhibited by glucose-6-phosphate.
Indicate whether the statement is true or false. If the statement is false, explain why it is
false.
Vitamin C is a good reducing agent, meaning it keeps things reduced by undergoing
irreversible oxidation; thus, it must continuously be replaced by dietary sources.
Indicate whether the statement is true or false. If the statement is false, explain why it is
false.
Gut bacteria can produce some vitamins, but this rarely contributes to our requirements
because they are not absorbed.
Indicate whether the statement is true or false. If the statement is false, explain why it is
false.
Iron regulatory protein (IRE-BP) is activated (i.e., to bind IREs) by iron.
Two hormones that act at the distal renal tubular site to regulate plasma cation levels
are: _____ and _____.
Pyruvate dehydrogenase is positively modulated by _____ and _____.
A homopolysaccharide that is important as a storage compound in human body is
_____, which can be enzymatically dismantled to produce _____.
What is the significance of vitamin C to carnitine and fat metabolism?
Pharmacologic doses of 2 vitamins, _____ and _____, are used therapeutically to lower
serum cholesterol and alleviate premenstrual syndrome, respectively.
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.CCK on the release of bile
Describe the transport system that allows for fatty acid synthesis and the molecules
involved in transferring acetyl-CoA into cytoplasm.
List the three mechanisms that can be used to regulate the function of a protein (e.g., an
enzyme) and briefly (1-2 sentences) describe their key features.
The melting temperature of the lipids in the lipid bilayer of the plasma membrane is
_____ than normal mammalian body temperature because it generally contains a
relatively large proportion of _____ fatty acids. Explain the physiological significance
for human beings of this statement by relating structure to function.
