In the minority of cases of familial hypercholesterolemia, mutations to PCSK9 gene lead to conformation changes of ___ receptors that lead to its destruction
LDL
Presence of apolipoprotein(a) doubles the risk of _______
atherosclerosis
A 45-year-old with hyperlipidemia has elevated molecules that
transport dietary triglycerides from the
intestine. Which list best matches the major lipid
classes involved?
A. Cholesterol, bile salts, free
glycerol
B. Triglycerides, phospholipids, cholesterol
C.
Triglycerides, glycolipids, bile salts
D. Phospholipids, fatty
aldehydes, ceramides
B. Triglycerides, phospholipids, cholesterol
chylomicrons are made of these three things
A biochemist isolates a 16-carbon saturated fatty
acid with the formula CH₃(CH₂)₁₄COOH. Which
fatty acid is this?
A. Oleic acid
B. Stearic acid
C.
Palmitic acid
D. Linoleic acid
C. Palmitic acid
The triglycerides in human adipose
tissue are predominantly composed of which three fatty
acids?
A. Arachidonic, linoleic, linolenic
B. Palmitic,
oleic, stearic
C. Myristic, lauric, palmitoleic
D.
Stearic, arachidonic, linoleic
B. Palmitic, oleic, stearic
A fatty acid is described as having an 18-carbon
chain and being fully saturated with
hydrogen. Which fatty acid fits this description?
A.
Oleic acid
B. Myristic acid
C. Palmitic acid
D.
Stearic acid
D. Stearic acid
A lipid analyst reports an 18-carbon fatty acid with
a single double bond in the middle of its chain.
Which is most consistent?
A. Oleic acid
B. Palmitic
acid
C. Stearic acid
D. Lauric acid
A. Oleic acid
A 16-carbon fatty acid that is fully saturated is
most likely:
A. Stearic acid
B. Palmitic acid
C.
Oleic acid
D. Arachidonic acid
B. Palmitic acid
A researcher notes a structural protein lightly adsorbed to
the outer surface of chylomicrons, important for their
stability in plasma. Which protein
is this?
A. Apoprotein A-I
B. Apoprotein C-II
C.
Apoprotein E
D. Apoprotein B
D. Apoprotein B
A patient with lipoprotein lipase deficiency shows
markedly elevated triglyceride-rich chylomicrons.
Normally, what is the key action of lipoprotein
lipase on these particles?
A. Esterifies cholesterol
within chylomicrons
B. Hydrolyzes triglycerides at capillary
endothelium
C. Transfers apoproteins between lipoproteins
D. Oxidizes fatty acids within hepatocytes
B. Hydrolyzes triglycerides at capillary endothelium
After extensive removal of triglycerides from
circulating chylomicrons, what happens next to
these cholesterol-enriched particles?
A. Spontaneously
disintegrate in plasma
B. Rapidly cleared as chylomicron
remnants
C. Converted directly into VLDL particles
D.
Stored intact in adipocytes
B. Rapidly cleared as chylomicron remnants
Chylomicron remnants are taken up by the
liver. To which cells do they primarily bind within
hepatic sinusoids?
A. Endothelial cells
B. Kupffer
macrophage cells
C. Ito (stellate) fat-storing cells
D.
Hepatocyte canalicular cells
B. Kupffer macrophage cells
A mutation that disrupts apolipoprotein E would most
directly impair which process related to dietary lipid
transport?
A. Activation of lipoprotein lipase on
endothelium
B. Assembly of nascent chylomicrons in
enterocytes
C. Stabilization of LDL particles in
circulation
D. Binding of chylomicron remnants to hepatic receptors
D. Binding of chylomicron remnants to hepatic receptors
During prolonged fasting, adipocytes sense
low glucose availability. Which specific
glucose-derived metabolite becomes insufficient,
favoring triglyceride hydrolysis in fat
cells?
A. Fructose-1,6-bisphosphate
B.
Alpha-glycerophosphate
C. Oxaloacetate
D. Pyruvate
B. Alpha-glycerophosphate
A hormone-driven
rise in circulating free fatty acids is
observed during stress. Which enzyme in adipose tissue is acutely
activated by endocrine hormones to accelerate triglyceride
breakdown?
A. Lipoprotein lipase
B. Acetyl-CoA
carboxylase
C. Hormone-sensitive lipase
D. HMG-CoA reductase
C. Hormone-sensitive lipase
In addition to free fatty acids, which other major
forms of fatty acids are normally present in plasma?
A. Ceramides and gangliosides mainly
B. Esters of
glycerol and cholesterol
C. Sphingomyelin and cardiolipin
esters
D. Free aldehydes and peroxides
B. Esters of glycerol and cholesterol
A pharmacologist studies turnover of plasma free fatty
acids. Which statement best describes their kinetics under
resting conditions?
A. Turnover rate occurs only
postprandially
B. Turnover rate is negligible at rest
C.
Turnover rate is very slow
D. Turnover rate is extremely rapid
D. Turnover rate is extremely rapid
Conditions that increase the rate of fat utilization
for cellular energy will typically:
A. Lower plasma free fatty
acid concentration
B. Have no effect on plasma lipids
C.
Increase plasma free fatty acid concentration
D. Shift fatty
acids entirely into chylomicrons
C. Increase plasma free fatty acid concentration
Marked elevations of plasma free fatty
acids are most characteristic of which conditions?
A.
Hypothyroidism and chronic liver failure
B. Nephrotic syndrome
with heavy proteinuria
C. Acute pancreatitis after large fatty
meals
D. Poorly controlled diabetes and prolonged starvation
D. Poorly controlled diabetes and prolonged starvation
Under normal resting conditions, approximately how
many free fatty acid molecules bind to each albumin molecule in
plasma?
A. About three fatty acids per albumin
B. About
one fatty acid per albumin
C. About ten fatty acids per
albumin
D. About thirty fatty acids per albumin
A. About three fatty acids per albumin
When demand for fatty acid transport becomes
extreme, as many as how many fatty acid molecules can bind a
single albumin molecule?
A. Ten fatty acids per albumin
B.
Thirty fatty acids per albumin
C. Three fatty acids per
albumin
D. Sixty fatty acids per albumin
B. Thirty fatty acids per albumin
Which description best defines plasma lipoproteins?
A. Micelles of bile salts and cholesterol
B. Complexes of
glycogen, protein, and lipid
C. Particles with triglycerides,
cholesterol, phospholipids, protein
D. Vesicles containing only
phospholipids and protein
C. Particles with triglycerides, cholesterol, phospholipids, protein
Which list correctly names the four major plasma
lipoprotein classes?
A. VLDL, IDL, LDL, HDL
B.
Chylomicrons, VLDL, LDL, albumin
C. HDL, myelin, chylomicrons,
VLDL
D. IDL, bile salts, LDL, HDL
A. VLDL, IDL, LDL, HDL
VLDL particles are characterized by which
composition?
A. High protein, low cholesterol and
phospholipids
B. High cholesterol, minimal triglyceride or
protein
C. Equal triglycerides, cholesterol, and protein
D. High triglycerides, moderate cholesterol and phospholipids
D. High triglycerides, moderate cholesterol and phospholipids
Intermediate-density lipoproteins (IDLs) are best
described as:
A. HDLs that have gained additional protein
B. VLDLs partially depleted of triglycerides
C. LDLs lacking
apolipoprotein B entirely
D. Chylomicron remnants enriched in triglycerides
B. VLDLs partially depleted of triglycerides
Low-density lipoproteins (LDLs) are formed:
A.
Directly from HDL remodeling
B. By intestinal assembly and
secretion of chylomicrons
C. From IDLs after removal of most
triglycerides
D. Only during severe hypercholesterolemia episodes
C. From IDLs after removal of most triglycerides
Which statement best characterizes high-density lipoproteins (HDLs)?
A. High protein, smaller cholesterol and phospholipids
B.
High triglycerides with minimal protein content
C. High
cholesterol with negligible phospholipids
D. High triglycerides
and cholesterol but no protein
A. High protein, smaller cholesterol and phospholipids
In adults, almost all plasma lipoproteins are
synthesized primarily in the:
A. Bone marrow
hematopoietic cells
B. Endothelial cells of systemic
capillaries
C. Adipocytes within subcutaneous tissue
D.
Hepatocytes of the liver
D. Hepatocytes of the liver
During intestinal absorption of dietary fatty acids,
small amounts of HDL are additionally synthesized in
which location?
A. Pancreatic acinar cell cytoplasm
B.
Intestinal epithelial cells of the mucosa
C. Renal proximal
tubular epithelium
D. Skeletal muscle fiber sarcoplasm
B. Intestinal epithelial cells of the mucosa
What is the primary function of plasma lipoproteins?
A. Buffering sudden changes in blood pH
B. Providing
oncotic pressure within plasma
C. Transporting lipid components
through the bloodstream
D. Catalyzing triglyceride synthesis in tissues
C. Transporting lipid components through the bloodstream
VLDL particles leaving the liver primarily deliver
newly synthesized triglycerides to which
tissue?
A. Adipose tissue for storage
B. Renal cortex for
oxidation
C. Cerebral white matter myelin
D. Skeletal
muscle exclusively
A. Adipose tissue for storage
Beyond serving as an energy reservoir,
stored adipose fat additionally:
A.
Synthesizes catecholamines for stress responses
B. Produces
renin to regulate blood pressure
C. Detoxifies xenobiotics like
hepatic cytochrome
D. Insulates body and secretes leptin and adiponectin
D. Insulates body and secretes leptin and adiponectin
Which statement best describes typical white
adipocytes in adipose tissue?
A. Derived from
myocytes
B. Modified fibroblasts
C. Epithelial cells
D. Macrophages
B. Modified fibroblasts
In adipose tissue, the
triglycerides stored within fat
cells are predominantly in which physical state at body
temperature?
A. Solid crystalline form
B. Highly volatile
gaseous form
C. Liquid form within the cell
D. Amorphous
glass-like solid state
C. Liquid form within the cell
During prolonged exposure to cold, adipocyte triglyceride fatty
acid chains are remodeled over weeks so that they:
A.
Become shorter or more unsaturated
B. Become longer and fully
saturated
C. Convert to cholesterol esters within
membranes
D. Solidify into waxes, preventing circulation
A. Become shorter or more unsaturated
Which enzymes permit dynamic exchange of
triglyceride-derived fatty acids between
adipose tissue and circulating
blood?
A. Transaminases in hepatic mitochondria
B. Cyclooxygenases in endothelial cells
C. Dehydrogenases in
skeletal muscle
D. Tissue lipases within adipose depots
D. Tissue lipases within adipose depots
In a healthy adult, triglycerides stored in
adipose fat cells are typically renewed
approximately every:
A. Two to three days
B. Two to three
weeks
C. Two to three months
D. Two to three years
B. Two to three weeks
Which set best describes the principal functions of the liver in
lipid metabolism?
A. Bile salt synthesis and storage
B.
Glucose oxidation and ketone body synthesis
C. Fatty acid
degradation, triglyceride and other lipid synthesis
D. Urea,
uric acid, and creatinine formation
C. Fatty acid degradation, triglyceride and other lipid synthesis
Large accumulations of fat in hepatocytes are most likely
during:
A. High-carbohydrate feeding with minimal fat
B.
Short-term fasting with high insulin levels
C. Hyperthyroidism
with increased carbohydrate oxidation
D. Early starvation,
diabetes, preferential fat use
D. Early starvation, diabetes, preferential fat use
A young patient has near-total absence of adipose
tissue, very low measured adipocyte mass,
and a massively fatty liver. This picture is most
consistent with:
A. Lipodystrophy
B. Nonalcoholic fatty
liver disease
C. Familial hypercholesterolemia type IIa
D.
Hereditary fructose intolerance
A. Lipodystrophy
Which statement about handling of fatty acids is correct?
A.
Liver hepatocytes desaturate fatty acids
B. Adipocytes uniquely
desaturate circulating cholesterol
C. Skeletal muscle
desaturates long-chain fatty acids
D. Red blood cells desaturate
membrane lipids
A. Liver hepatocytes desaturate fatty acids
The first stage in using stored triglycerides for
energy in tissues is:
A. Oxidation of glycerol
in mitochondria
B. Hydrolysis to fatty acids and glycerol
C. Conversion to phospholipids in membranes
D. Direct
phosphorylation to glycerol three phosphate
B. Hydrolysis to fatty acids and glycerol
Once glycerol enters cells after
triglyceride breakdown, it is rapidly converted to:
A. Glycerol-3-phosphate via intracellular enzymes
B.
Dihydroxyacetone phosphate without ATP use
C. Glucose by hepatic
gluconeogenesis alone
D. Triglyceride resynthesized in mitochondria
A. Glycerol-3-phosphate via intracellular enzymes
Degradation and oxidation of fatty acids for energy
occur primarily in which site?
A. Cytosol of hepatocytes
primarily
B. Smooth endoplasmic reticulum lumen
C.
Mitochondrial matrix of the cell
D. Peroxisomal matrix during fasting
C. Mitochondrial matrix of the cell
Long-chain fatty acids must be transferred
into mitochondria for β-oxidation. Which carrier mediates
this transport?
A. Coenzyme A alone without transporters
B. Albumin within mitochondrial intermembrane space
C. Carnitine
shuttling fatty acyl groups
D. Biotin transporting activated
carboxyl groups
C. Carnitine shuttling fatty acyl groups
The mitochondrial β-oxidation spiral primarily
degrades fatty acids by:
A. Adding carbons onto growing acyl
chains
B. Sequentially removing two-carbon acetyl-CoA
units
C. Converting them directly to glucose
D. Reducing
them to glycerol backbones
B. Sequentially removing two-carbon acetyl-CoA units
What is the first step in mitochondrial
β-oxidation of a fatty acid?
A. Oxidation of the
beta-carbon directly
B. Cleavage releasing acetyl-CoA
immediately
C. Condensation with oxaloacetate to citrate
D. Formation of fatty acyl-CoA from fatty acid
D. Formation of fatty acyl-CoA from fatty acid
During steps two through four of β-oxidation, the
β-carbon of the fatty acyl-CoA undergoes:
A. Progressive
oxidation after binding molecular oxygen
B. Phosphorylation by
ATP at beta-carbon
C. Carboxylation to form malonyl-CoA
intermediate
D. Reduction to fully saturated hydrocarbon chain
A. Progressive oxidation after binding molecular oxygen
In step five of β-oxidation, the “right-hand”
two-carbon fragment is:
A. Attached to glycerol forming
triglyceride
B. Released as acetyl-CoA; new fatty acyl-CoA
forms
C. Converted directly to oxaloacetate intermediate
D. Recycled into cytosol for resynthesis
B. Released as acetyl-CoA; new fatty acyl-CoA forms
What happens to the shortened fatty acyl-CoA
produced after one turn of β-oxidation?
A. It leaves
mitochondria for peroxisomal oxidation
B. It is immediately
converted into ketone bodies
C. It is esterified into membrane
phospholipids
D. It re-enters steps two through five repeatedly
D. It re-enters steps two through five repeatedly
The acetyl-CoA units produced by
β-oxidation primarily enter which pathway next for
full oxidation?
A. Citric acid cycle in mitochondrial
matrix
B. Pentose phosphate pathway in cytosol
C. Urea
cycle in liver mitochondria
D. Gluconeogenesis from acetyl-CoA carbons
A. Citric acid cycle in mitochondrial matrix
Within the citric acid cycle, acetyl-CoA condenses with
oxaloacetate to form a molecule that is later degraded to CO₂ and hydrogen atoms.
This initial product is:
A. Malate
B. Succinyl-CoA
C. Citric acid
D. Acetoacetate
C. Citric acid
Complete β-oxidation of one stearic acid (18:0)
molecule yields how many acetyl-CoA units?
A. Nine acetyl-CoA
molecules
B. Six acetyl-CoA molecules
C. Twelve
acetyl-CoA molecules
D. Eighteen acetyl-CoA molecules
A. Nine acetyl-CoA molecules
Regarding the flavoprotein-linked hydrogens produced
during stearic acid oxidation, which pairing of number and ATP yield
is correct?
A. Thirty-four hydrogens, 1.5 ATP each
B.
Thirty-four hydrogens, one ATP per hydrogen
C. Seventy
hydrogens, one ATP each
D. Seventy hydrogens, 1.5 ATP each
A. Thirty-four hydrogens, 1.5 ATP each
For the NADH-linked hydrogens generated from stearic
acid degradation, which pairing of number and ATP yield is
correct?
A. Seventy hydrogens, 1.5 ATP each
B. Seventy
hydrogens, one ATP each
C. Thirty-four hydrogens, one ATP
each
D. Thirty-four hydrogens, 1.5 ATP each
B. Seventy hydrogens, one ATP each
Complete oxidation of one stearic acid molecule
yields approximately how many ATP before subtracting
activation costs?
A. 139 ATP
B. 146 ATP
C. 148 ATP
D. 104 ATP
C. 148 ATP
Two high-energy phosphate bonds are used to activate stearic acid
with CoA. What is the approximate
net ATP yield per molecule of stearic acid?
A. 146 ATP
B. 139 ATP
C. 148 ATP
D. 104 ATP
A. 146 ATP
How many acetyl-CoA molecules condense to form one
molecule of acetoacetic acid?
A. One
acetyl-CoA
B. Three acetyl-CoA
C. Four acetyl-CoA
D.
Two acetyl-CoA
D. Two acetyl-CoA
In the liver, a portion of acetoacetic acid is
further converted into which ketone body?
A. Acetone
B.
Beta-hydroxybutyric acid
C. Acetoacetyl-CoA
D. Propionic acid
B. Beta-hydroxybutyric acid
Biochemically, ketosis is defined by increased blood
levels of:
A. Glucose and lactate mainly
B. Triglycerides
and free fatty acids
C. Cholesterol esters and
phospholipids
D. Acetoacetic acid, beta-hydroxybutyrate, acetone
D. Acetoacetic acid, beta-hydroxybutyrate, acetone
Which hormonal pattern best promotes removal of fatty
acids from adipose tissue and favors
ketone body formation?
A. High insulin, low glucagon, low cortisol
B. High
glucocorticoids, high glucagon, low insulin
C. Low
glucocorticoids, low glucagon, high insulin
D. High insulin,
high glucagon, high cortisol
B. High glucocorticoids, high glucagon, low insulin
In severe carbohydrate deficiency, why are cells
limited in how many ketone bodies they can
oxidize?
A. Oxaloacetate deficiency limits
acetyl-CoA entry
B. Lack of carnitine stops ketone
transport
C. Ketone bodies cannot enter mitochondria
D.
Ketone oxidation requires hepatic-specific enzymes
A. Oxaloacetate deficiency limits acetyl-CoA entry
(Low carbohydrate → OAA used for gluconeogenesis → less OAA for TCA cycle → limited ketone-derived acetyl-CoA oxidation.)
Which population typically consumes a predominantly fat-based diet
yet usually does not develop ketosis because of long-term
metabolic adaptation?
A. Strict vegans in urban settings
B. Patients starting ketogenic diet suddenly
C. Marathon runners
during single race
D. Eskimos (Inuit) on traditional diet
D. Eskimos (Inuit) on traditional diet
Once newly synthesized fatty acid chains reach a
certain length, they typically bind glycerol to form
triglycerides. This occurs when the chains are:
A. Six
to eight carbons long
B. Fourteen to eighteen carbons long
C. Two to four carbons long
D. Twenty-two to twenty-four carbons long
B. Fourteen to eighteen carbons long
During triglyceride synthesis in adipose tissue, the glycerol
portion of the molecule is mainly supplied by:
A. Free
glycerol from the plasma
B. Dihydroxyacetone phosphate
directly
C. Alpha-glycerophosphate generated from glucose
D. Lactate produced during glycolysis
C. Alpha-glycerophosphate generated from glucose
The total amount of glycogen that can be
stored in the body of an average
adult is closest to:
A. Several kilograms stored in liver
B. About one kilogram bodywide
C. Several tens of grams
only
D. Only a few hundred grams total
D. Only a few hundred grams total
Compared with total carbohydrate
stores, the average person has approximately how much
more energy stored as fat?
A. About
tenfold more energy
B. About one hundred fiftyfold more
C. About twofold more energy
D. About twentyfold more energy
B. About one hundred fiftyfold more
Each gram of fat contains approximately how many
times the calories of one gram of
glycogen?
A. About the same calories
B. About
five times more
C. About two and a half times
D. About
ten times more
C. About two and a half times
In the absence of insulin, which statement about
lipid synthesis is most accurate?
A. Carbohydrates cannot be
converted into fat
B. Amino acids cannot form
triglycerides
C. Fatty acids cannot be oxidized at all
D.
Ketone bodies cannot be generated hepatically
A. Carbohydrates cannot be converted into fat
Which statement best describes how amino acids can contribute to
triglyceride synthesis?
A. They directly polymerize into fatty
acids
B. They replace glycerol in triglycerides
C. They
only supply nitrogen for lipids
D. They are converted to
acetyl-CoA first
D. They are converted to acetyl-CoA first
A sedentary patient adopts a very high-carbohydrate, low-fat diet.
When excess carbohydrate is available, which substrate is
preferentially oxidized for energy?
A. Fatty acids
B.
Ketone bodies
C. Amino acids
D. Carbohydrates
D. Carbohydrates
In an adipocyte loaded with glucose, intracellular
α-glycerophosphate levels rise. What happens to free fatty
acids under these conditions?
A. Oxidized completely to
CO₂
B. Esterified as stored triglycerides
C. Converted
mainly to ketone bodies
D. Released unbound into plasma
B. Esterified as stored triglycerides
↑ glucose → ↑ glycerol-3-phosphate → ↑ fatty acid esterification → ↑ triglyceride storage
Excess α-glycerophosphate in adipose tissue shifts
the equilibrium between fatty acids and triglycerides toward:
A.
Free fatty acid release
B. Phospholipid degradation
predominates
C. Cholesterol ester hydrolysis
D.
Triglyceride storage within adipocytes
D. Triglyceride storage within adipocytes
The first step in converting carbohydrate to fat is best described as
a:
A. Nonregulated condensation of acetyl-CoA
B.
Irreversible ketone body formation step
C. Strictly
rate-limiting regulatory step
D. Purely mitochondrial transport process
C. Strictly rate-limiting regulatory step
The initial committed reaction for converting
carbohydrate-derived acetyl-CoA to fatty acids
is:
A. Reduction of malonyl-CoA to acetyl-CoA
B.
Carboxylation of acetyl-CoA to malonyl-CoA
C. Condensation of
acetyl-CoA with oxaloacetate
D. Transamination of acetyl-CoA to alanine
B. Carboxylation of acetyl-CoA to malonyl-CoA
The carboxylation of acetyl-CoA to form
malonyl-CoA in fatty acid synthesis is catalyzed
by:
A. Pyruvate carboxylase
B. Malic enzyme
C. Fatty
acid synthase
D. Acetyl-CoA carboxylase
D. Acetyl-CoA carboxylase
A patient with new-onset type 1 diabetes has very low insulin levels.
Which metabolic change is most expected?
A. Reduced glucose use
and increased fat storage
B. Increased glucose utilization and
lipogenesis
C. Increased lipoprotein lipase in adipose
D.
Increased adipocyte glucose uptake
A. Reduced glucose use and increased fat storage
During intense exercise, which enzyme do
epinephrine and norepinephrine
directly activate to mobilize fatty acids from adipose
tissue?
A. Lipoprotein lipase in capillaries
B.
Hormone-sensitive triglyceride lipase
C. HMG-CoA reductase in
hepatocytes
D. Carnitine acyltransferase in muscle
B. Hormone-sensitive triglyceride lipase
Corticotropin and glucocorticoids
enhance lipolysis in adipose tissue mainly by
activating:
A. Adipocyte lipoprotein lipase
B.
Hormone-sensitive triglyceride lipase
C. Pancreatic
phospholipase A₂
D. Hepatic cholesterol ester hydrolase
B. Hormone-sensitive triglyceride lipase
A patient with central obesity, striae, hypertension, chronic
hypercortisolism, and elevated ACTH develops ketosis despite no change
in diet. Which diagnosis best explains the fat mobilization–induced
ketosis?
A. Addison’s disease
B. Diabetic ketoacidosis
only
C. Primary hyperparathyroidism
D. Cushing’s syndrome
D. Cushing’s syndrome
Cushing’s syndrome → ↑ cortisol → ↑ lipolysis → ↑ free fatty acids → ↑ hepatic ketogenesis
Growth hormone is:
A. Mildly ketogenic, promoting fat
mobilization
B. Strongly anti-ketogenic, inhibiting
lipolysis
C. Exclusive increase in hepatic glycogen stores
D. Inhibition of hormone-sensitive triglyceride lipase
A. Mildly ketogenic, promoting fat mobilization
Thyroid hormone causes rapid fat mobilization primarily because
it:
A. Directly inhibits adipocyte insulin receptors
B.
Directly activates lipoprotein lipase only
C. Directly converts
triglycerides into ketones
D. Increases overall cellular energy metabolism
D. Increases overall cellular energy metabolism
Which set lists the three major classes of body
phospholipids?
A. Lecithin, cardiolipin,
plasmalogens
B. Cephalins, gangliosides, cerebrosides
C.
Lecithins, cephalins, sphingomyelin
D. Sphingomyelin,
cholesterol, triglycerides
C. Lecithins, cephalins, sphingomyelin
A typical membrane phospholipid molecule is composed of:
A. Two
sugars, nitrogen base, sulfate
B. Fatty acids, nitrogen base,
single phosphate
C. Cholesterol, phosphates, multiple nitrogen
bases
D. Triglycerides, sulfur groups, two phosphates
B. Fatty acids, nitrogen base, single phosphate
A deficiency of which compound would directly impair
lecithin synthesis because it serves as its
nitrogenous base?
A. Ethanolamine
B. Serine
C. Inositol
D. Choline
D. Choline
Some cephalins require which molecule for their
formation?
A. Carnitine
B. S-adenosylmethionine
C.
Inositol
D. Choline
C. Inositol
Phospholipids participate in structural
elements and can donate phosphate groups.
They also act as:
A. Sole long-term energy stores in
adipocytes
B. Components of lipoproteins, thromboplastin, neural
insulation
C. Primary oxygen carriers within erythrocytes
D. Exclusive precursors of all steroid hormones
B. Components of lipoproteins, thromboplastin, neural insulation
Which statement best describes cholesterol’s
solubility properties?
A. Highly water and lipid soluble
B. Water insoluble, protein soluble
C. Equally soluble in water
and fat
D. Highly fat soluble, slightly water soluble
D. Highly fat soluble, slightly water soluble
Modifying the sterol nucleus with different side
chains can yield:
A. Cholesterol, cholic acid, steroid
hormones
B. Triglycerides, phospholipids, ketone bodies
C.
Glucose, lactate, amino acids
D. Bile pigments, urea, creatinine
A. Cholesterol, cholic acid, steroid hormones
Increased intake of exogenous
cholesterol affects hepatic cholesterol metabolism by:
A. Increasing endogenous cholesterol synthesis markedly
B.
Eliminating intestinal cholesterol absorption completely
C.
Inhibiting endogenous cholesterol production by feedback
D.
Having no effect on hepatic synthesis
C. Inhibiting endogenous cholesterol production by feedback
Which endocrine deficiency pattern is most likely to raise blood
cholesterol levels?
A. Lack of thyroid hormone or insulin
B. Excess insulin plus excess thyroxine
C. Lack of cortisol plus
epinephrine
D. Excess glucagon plus aldosterone
A. Lack of thyroid hormone or insulin
Which dietary change would be expected to slightly decrease
blood cholesterol concentration?
A. Increase intake of
unsaturated fatty acids
B. Increase intake of saturated animal
fats
C. Increase exogenous cholesterol-rich foods
D.
Eliminate all dietary fat entirely
A. Increase intake of unsaturated fatty acids
The most abundant non-membranous use of cholesterol in the body is
formation of:
A. Steroid hormones in adrenal cortex
B.
Cholic acid synthesized in liver
C. Vitamin D in skin and
kidney
D. Cell membrane cholesterol in hepatocytes
A. Steroid hormones in adrenal cortex
High cholesterol content in the
corneum of the skin mainly:
A. Resists
water-soluble absorption and chemical injury
B. Enhances
conduction along peripheral nerves
C. Promotes capillary
angiogenesis in dermis
D. Increases transepidermal water
evaporation greatly
A. Resists water-soluble absorption and chemical injury
Endothelial injury in early
atherogenesis increases adhesion molecule
expression and reduces release of which anti-adhesive
mediator?
A. Prostacyclin mediated platelet inhibitors
B.
Endothelin derived vasoconstrictor peptides
C. Nitric oxide
mediated anti adhesion signals
D. Angiotensin II mediated vasoconstrictors
C. Nitric oxide mediated anti adhesion signals
Aggregation of macrophage foam cells along the
intima produces what visible lesion
in arteries?
A. Organized fibrous fibrofatty cap
B. A
visible intimal fatty streak
C. Calcified, ulcerated fibrous
plaque
D. Mural thrombus overlying rupture
B. A visible intimal fatty streak
Over time, an early fatty streak most typically
progresses to:
A. Non-occlusive mural thrombus
B. Medial
calcific degenerative lesion
C. Small-vessel hyaline
arteriolosclerosis
D. Larger fibrous atherosclerotic plaque
D. Larger fibrous atherosclerotic plaque
Activated macrophages within a developing
plaque most importantly:
A. Decrease cytokine release
and cell turnover
B. Promote inflammation and smooth muscle
growth
C. Reduce lipid deposition in the intima
D. Induce
regression of existing fibrous caps
B. Promote inflammation and smooth muscle growth
As lipid deposits and cellular
proliferation expand within an artery, a key hemodynamic
consequence is:
A. Increased downstream perfusion pressure
B. Immediate vessel rupture and dissection
C. Luminal blood flow
becomes significantly reduced
D. Complete elimination of
turbulent flow patterns
C. Luminal blood flow becomes significantly reduced
A 20-year-old with tendon xanthomas and very
high LDL has familial hypercholesterolemia. The primary
inherited defect is:
A. Overexpression of hepatic HMG-CoA
reductase
B. Defective genes for LDL receptors
C.
Excessive synthesis of apolipoprotein A-I
D. Absent intestinal
chylomicron formation
B. Defective genes for LDL receptors
In familial hypercholesterolemia lacking functional
LDL receptors, hepatic lipid handling is best described as:
A.
Increased uptake of circulating LDL particles
B. Decreased VLDL
secretion into the plasma
C. Complete failure to synthesize
cholesterol
D. Liver overproduces cholesterol and VLDL
D. Liver overproduces cholesterol and VLDL
Epidemiologic studies show which group has a higher incidence of
atherosclerosis, suggesting a role for sex hormones?
A.
Premenopausal women only
B. Children younger than ten
years
C. Men have higher atherosclerosis incidence
D.
Postmenopausal women regardless of therapy
C. Men have higher atherosclerosis incidence
Bile acid sequestrants for high cholesterol?
A. Inhibit
intestinal cholesterol absorption directly
B. Bind bile acids
and increase fecal loss
C. Irreversibly inhibit LDL receptor
synthesis
D. Completely block hepatic VLDL secretion
B. Bind bile acids and increase fecal loss
Another patient is started on a statin. These drugs lower cholesterol
primarily by:
A. Blocking bile salt reabsorption in ileum
B. Inhibiting intestinal chylomicron assembly
C. Stimulating LDL
receptor degradation pathways
D. Inhibiting HMG CoA reductase competitively
D. Inhibiting HMG CoA reductase competitively