End of chapter problems

Question 1

The statins are the major class of medications used to lower elevated serum cholesterol by initially inhibiting the major rate-limiting step of cholesterol synthesis. Which metabolite of the pathway would accumulate under conditions of taking a statin?
A. Acetoacetyl-CoA
B. HMG-CoA
C. Mevalonate
D. Squalene
E. Steroid ring

Answer 1

B. HMG-CoA

Question 2

Cholesterol, and its precursors and products, have a variety of functions within cells. Which one statement correctly describes a function of a cholesterol precursor, cholesterol itself, or a product derived from cholesterol?
A. Cholesterol is hydrophilic
B. Steroid hormones are precursors of cholesterol
C. Precursors of cholesterol can be converted to vitamin D
D. Cholesterol can appear in its free unesterified form in the core of lipoproteins particles
E. Malonyl-CoA is the major precursor of cholesterol synthesis

Answer 2

C. Precursors of cholesterol can be converted to vitamin D

Question 3

A new patient is being evaluated for cardiovascular disease. The values for his lipid panel are a total cholesterol of 400mg/dL, an HDL reading of 35 mg/dL, and a triglyceride reading of 200 mg/dL. What would be his calculated LDL cholesterol reading?
A. 165
B. 193
C. 205
D.325
E. 365

Answer 3

D. 325

Question 4

Which one of the following apolipoproteins acts as a cofactor activator of the enzyme LPL?
A. ApoCIII
B. ApoCII
C. ApoB-100
D. ApoB-48s
E. ApoE

Answer 4

B. ApoCII

Question 5

Which one of the following sequences places the lipoproteins in the order of most dense to least dense?
A. HDL/VLDL/chylomicrons/LDL
B. HDL/LDL/VLDL/chylomicrons
C. LDL/chylomicrons/HDL/VLDL
D. VLDL/chylomicrons/LDL/HDL
E. LDL/chylomicrons/VLDL/HDL

Answer 5

B. HDL/LDL/VLDL/chylomicrons

Question 6

Which one of the following would you expect to observe in a patient lacking microsomal triglyceride transfer protein (MTP) after eating a normal diet, in which each meal consisted of 30% fat?
A. Constipation
B. Elevated chylomicrons
C. Steatorrhea
D. Elevated VLDL
E. Elevated IDL

Answer 6

C. Steatorrhea

Question 7

Patients with elevated serum levels LDL levels are first encouraged to reduce these levels through a combination of diet and exercise. If this fails, they are often prescribed statins. The key for statin treatment reducing circulating cholesterol levels is which one of the following?
A. Reduced synthesis of chylomicrons
B. Increased activity of LPL
C. Reduced synthesis of HDL
D. Upregulation of LDL receptors
E. Increased activity of CETP

Answer 7

D. Upregulation of LDL receptors

Question 8

A consequence of abetalipoproteinemia is a fatty liver. This occurs because of which one of the following?
A. Inability to produce VLDL
B. Inability to produce chylomicrons
C. Inability to produce HDL
D. Inability to produce trigylceride
E. Inability to produce LPL

Answer 8

A. Inability to produce VLDL

Question 9

Hormones are typically synthesized in one type of tissue, often in response to the release of a stimulatory hormone. Which one of the following correctly matches a hormone with its stimulatory hormone and its site of synthesis?
A. Cortisol, ACTH, adrenal cortex
B. Aldosterone, ACTH, adrenal cortex
C. Testosterone, FSH, Leydig cells
D. Estrogen, LH, ovarian follicle
E. Progesterone, LH, ovarian follicle

Answer 9

A. Cortisol, ACTH, adrenal cortex

Question 10

Because the steroid nucleus cannot be degraded by the human body, excretion of bile salts in stool serves as a major route of removal of steroids from the body. Which one of the following must occur to bile salts in order for bile salts to be excreted in the stool?
A. Intestinal bacteria deconjugate bile salts
B. Intestinal bacteria conjugate bile salts
C. ATP and coenzyme Q conjugate bile salts
D. ATP and coenzyme A deconjugate bile salts
E. Enterohepatic circulation occurs at 100% efficiency

Answer 10

A. Intestinal bacteria deconjugate bile salts

Question 11

A 20-year-old woman with diabetes mellitus was admitted to the hospital in a semiconscious state with fever, nausea, and vomiting. Her breath smelled of acetone. A urine sample was strongly positive for ketone bodies. Which one of the following statements about this woman is correct?
A. A blood glucose test will probably show that her blood glucose level is well below 80mg/dL
B. An injection of insulin will decrease ketone-body production
C. She should be given a glucose infusion so she will regain consciousness
D. Glucagon should be administered to stimulate glycogenolysis and gluconeogenesis in the liver
E. The acetone was produced by decarboxylation of the ketone body beta-hydroxybutyrate

Answer 11

B. An injection of insulin will decrease ketone-body production

Question 12

A woman was told by her physician to go on a low-fat diet. She decided to continue to consume the same number of calories by increasing her carbohydrate intake while decreasing her fat intake. Which of the following blood lipoprotein levels would be decreased as a consequence of her diet?
A. VLDL
B. IDL
C. HDL
D. Chylomicrons
E. HDL

Answer 12

D. Chylomicrons

Question 13

Assume that an individual has been eating excess calories daily such that he gain weight. Under which one of the following conditions will the person gain weight most rapidly?
A. If all the excess calories are from carbohydrate
B. If all the excess calories are from triacylglycerol
C. If all the excess calories are split 50%/50% between carbohydrate and triacylglycerol
D. If all the excess calories are split 25%/75% between carbohydrate and triacylglycerol
E. It makes no difference what form the excess calories are in

Answer 13

B. If all the excess calories are from triacylglycerol

Question 14

A chronic alcoholic has been admitted to the hospital because of a severe hypoglycemic episode brought about by excessive alcohol consumption for the past 5 days. A blood lipid analysis indicates much higher than expected VLDL levels. The elevated VLDL is attributable to which one of the following underlying causes?
A. Alcohol-induced inhibition of LPL
B. Elevated NADH levels in the liver
C. Alcohol-induced transcription of the ApoB-100 gene
D. NADH activation of phosphoenolpyruvate carboxykinase
E. Acetaldehyde induction of enzymes on the endoplasmic reticulum

Answer 14

B. Elevated NADH levels in the liver

Question 15

Certain patients with abetalipoproteinemia frequently have difficulty maintaining blood volume; their blood has trouble clotting. This symptom is attributable to which of the following?
A. Inability to produce chylomicrons
B. Inability to produce VLDL
C. Inability to produce synthesize clotting factors
D. Inability to synthesize fatty acids
E. Inability to absorb short-chain fatty acids

Answer 15

A. Inability to produce chylomicrons

Question 16

Which one of the following schemes most accurately depicts the timeline of the metabolic processes of the liver after a carbohydrate meal is ingested followed by 3 hours of fasting?
A. Glycolysis, glycogen synthesis, lipolysis, glycogenolysis, gluconeogenesis
B. Glycogen synthesis, lipolysis, glyocogenolysis, gluconeogenesis, glycogen synthesis
C. Glycolysis, lipolysis, glycogenolysis, gluconeogenesis, glycolysis
D. Glycogen synthesis, lipolysis, gluconeogenesis, glycolysis
E. Glycogen synthesis, glycogenolysis, lipolysis, gluconeogenesis

Answer 16

E. Glycogen synthesis, glycogenolysis, lipolysis, gluconeogenesis

Question 17

A person with type 1 diabetes who has neglected to take insulin for 2 days, yet who are normally, would exhibit elevated levels of circulating triglycerides because of which one of the following?
A. Reduced synthesis of alipoprotein CII
B. Reduced release of LPL from muscle and fat cells
C. increased synthesis of LDL
D. Reduced synthesis of chylomicrons
E. Reduced synthesis of VLDL

Answer 17

B. Reduced release of LPL from muscle and fat cells

Question 18

Under conditions of a low insulin/glucagon ratio, which one of the following allosteric modifiers in muscle can lead to a stimulation of both glycolysis and fatty acid oxidation
A. ATP
B. ADP
C. AMP
D. Acetyl CoA
E. Citrate

Answer 18

C. AMP

Question 19

Which one of the following is a major difference between patients with diabetes mellitus types 1 and 2?
A. In type 1, insulin levels are low and insulin resistance is high
B. In type 2, insulin levels are very low and insulin resistance is high
C. In both types, the patient is usually at or below ideal body weight
D. In type 1, C-peptide levels are very low
E. In type 1, the patient is usually overweight

Answer 19

D. In type 1, C-peptide levels are very low

Question 20

A patient is training for a half-marathon. After running 5 miles, which one of the following is providing most of the products for ATP generation in the muscles?
A. Muscle glycogen
B. Liver glycogen
C. Blood glucose
D. Ketone bodies
E. Fatty acids

Answer 20

E. fatty acids

Question 21

An individual with a deficiency in the conversion trypsinogen to trypsin would be expected to experience a more detrimental effect on protein digestion than an individual who was defective in any of the other digestive proteases. This is a result of which one of the following?
A. Trypsin has a greater and wider range of substrates on which to act
B. Trypsin activates pepsinogen, so digestion can begin in the stomach
C. Trypsin activates the other zymogens that are secreted by the pancreas
D. Trypsin activates enteropeptidase, which is needed to activate the other pancreatic zymogens
E. Trypsin inhibits motility, so the substrates can be hydrolyzed for longer periods

Answer 21

C. Trypsin activates the other zymogens that are secreted by the pancreas

Question 22

An individual has been shown to have a deficiency in an intestinal epithelial cell amino acid transport system for leucine. However, the individual shows no symptoms of amino acid deficiency. This could be because of which of the following?
A. The body synthesizes leucine to compensate for the transport defect
B. The kidney reabsorbs leucine and sends it to other tissues.
C. There are multiple transport systems for leucine.
D. Isoleucine takes the place of leucine in proteins
E. Leucine is not necessary for bulk protein synthesis

Answer 22

C. There are multiple transport systems for leucine.

Question 23

Kwashiorkor can result from which one of the following?
A. Consuming a calorie-deficient diet that is also deficient in protein
B. Consuming a calorie-adequate diet that is deficient in carbohydrates
C. Consuming a calorie-adequate diet that is deficient in fatty acids
D. Consuming a calorie-adequate diet that is deficient in proteins
E. Consuming a calorie-deficient diet that is primarily proteins.

Answer 23

D. Consuming a calorie-adequate diet that is deficient in proteins

Question 24

Which one of the following enzymes is activated through an autocatalytic process?
A. Enteropeptidase
B. Trypsinogen
C. Pepsinogen
D. Aminopeptidase
E. Proelastase

Answer 24

C. Pepsinogen

Question 25

Children with kwashiorkor usually have a fatty liver. This is the result of which one of the following? A. The high fat content of their diet B. The high carbohydrate content of their diet C. The high protein content of their diet D. The lack of substrates for gluconeogenesis in the liver E. The lack of substrates for protein synthesis in the liver F. The lack of substrates for glycogen synthesis in the liver

Answer 25

E. The lack of substrates for protein synthesis in the liver

Question 26

All of the nitrogen-containing compounds of the human body are synthesized from amino acids. Which one of the following statements about amino acid degradation is correct? A. Amino acid carbons can be stored only as glycogen B. The liver is the only site of amino acid oxidation C. The nitrogen of oxidized branched-chain amino acids must travel to the liver for disposal D. The nitrogen of amino acids is always excreted as urea E. The nitrogen of amino acids is only excreted by the kidney

Answer 26

C. The nitrogen of oxidized branched-chain amino acids must travel to the liver for disposal

Question 27

``` Proteases break down dietary proteins, and their release from the pancreas to the small intestine is often blocked in individuals with cystic fibrosis. Which one of the following is an example of a pancreatic protease? A. Pepsin B. Elastase C. Aminopeptidase D. Cathepsin E. Ubiquitin ```

Answer 27

B. Elastase

Question 28

A 38-year-old patient has developed COPD caused by an alpha1-antitrypsin deficiency. Which one of the following correctly describes alpha1-antitrypsin? A. It is synthesized by the lung B. It is a protease enhancer C. It enhances the action of trypsin in the lung D. It blocks the action of elastase in the lung E. It blocks the action of trypsin in the lung

Answer 28

D. It blocks the action of elastase in the lung

Question 29

``` Proteolytic enzymes must be secreted as zymogens that are activated, or they would auto digest themselves and the organs that produce them. Trypsinogen, a zymogen, is cleaved to form trypsin by a protease that is secreted by which one of the following? A. Stomach B. Pancreas C. Colon D. Liver E. Small intestine ```

Answer 29

E. Small intestine

Question 30

An adult patient is trying to increase his amount of muscle by ingesting protein-rich drinks daily without increasing his daily exercise routine. Which one of the following correctly describes a problem with this approach? A. Dietary proteins in excess of bodily needs pass unchanged and unabsorbed into the feces B. Dietary proteins in excess of bodily needs pass unchanged in the urine C. Dietary proteins in excess of bodily needs feed back and shut down pancreatic enzymes D. Dietary proteins in excess of bodily needs are stored as amino acids in the liver E. Dietary proteins in excess of bodily needs are converted to glycogen and triacylglycerols for storage.

Answer 30

E. Dietary proteins in excess of bodily needs are converted to glycogen and triacylglycerols for storage.

Question 31

As a third-year medical student, you examine your first patient. You find that he is 52 years old, has a round face, acne, and a large hump of fat on the back of his neck. He complains that he is too weak to mow the lawn. His fasting blood glucose level is 170 mg/dL. His plasma cortisol levels are 62 µg/mL. His plasma ACTH levels are 0 pg/mL. Based on the information given, if the patients problem is attributable to a single cause, the most likely diagnosis is which one of the following? A. Non-insulin-dependent diabetes mellitus B. Insulin-dependent diabetes mellitus C. A secretory tumor of the anterior pituitary D. A secretory tumor of the posterior pituitary E. A secretory tumor of the adrenal cortex

Answer 31

E. A secretory tumor of the adrenal cortex

Question 32

A woman was scheduled for a GH suppression test. If each of the following events occurred the morning of the test, which one of the events would be most likely to cause a decrease in GH levels/ A. She ate four large doughnuts for breakfast B. She was on estrogen replacement therapy and took her tablets after breakfast C. While unlocking her car, she was chased by the neighbor's vicious dog. D. She fell asleep at the start of the test and slept soundly until it was completed 1.5 hours later E. She forgot to eat breakfast before the test

Answer 32

A. She ate four large doughnuts for breakfast

Question 33

A dietary deficiency of iodine will lead to which one of the following? A. A direct effect on the synthesis of thyroglobulin on ribosomes B. An increased secretion of TSH C. Decreased production of TRH D. Increased heat production E. Weight loss

Answer 33

B. An increased secretion of TSH

Question 34

A woman whose thyroid gland was surgically removed was treated with 0.10 mg of thyroxine daily (tablet form). After 3 months of treatment, serial serum TSH levels ranged between 10 and 15 MIU/mL). She complained of fatigue, weight gain, and hoarseness. Her dose of thyroid hormone should be adjusted in which direction? A. Increased B. Decreased C. Stay the same

Answer 34

A. Increased

Question 35

``` Which one of the insulin counter regulatory hormones stimulates both amino acid release from the muscle and glycogenesis? A. Glucagon B. Epinephrine C. Cortisol D. Growth hormone E. Thyroid hormone ```

Answer 35

C. Cortisol

Question 36

Which of the following are hormones that would antagonize the actions of insulin (insulin counter regulatory hormones)? Choose the best one answer See book for table.

Answer 36

``` D. Erythropoietin- No Epinephrine-yes Norepinephrine-yes Somatostatin-Yes Growth hormone-Yes ```

Question 37

``` A patient has been diagnosed with acromegaly caused by a GH-secreting tumor in the anterior pituitary. The patient is prescribed an analog of somatostatin to suppress GH secretion form the tumor in order to treat the condition. This treatment will also lead to the suppression of which one of the following hormones? A. Epinephrine B. Norepinephrine C. Glucocorticoid D. Thyroid hormone E. Erythropoietin ```

Answer 37

D. Thyroid hormone

Question 38

``` A patient had a recent history of headaches, sweating, and rapid heart palpitations. The physician ordered a 24-hour urine test that indicated greatly elevated levels of VMA. This fining strongly suggests that the patient has which type of tumor? A. Prolactinoma B. GH-secreting hormone C. Insulinoma D. Glucagonoma E. Pheochromocytoma ```

Answer 38

E. Pheochromocytoma

Question 39

A new patient to your practice has been diagnosed with type 2 diabetes. Your treatment plan includes prescribing a drug that would be beneficial in lowering postprandial serum glucose levels. A class of such drug is which one of the following? A. Drugs that decrease levels of GIP B. Drugs that decrease levels of GLP-1 C. Drugs that increase levels of somatostatin D. Drugs that decrease levels of DPP-4 E. Drugs that increase levels of glucagon

Answer 39

D. Drugs that decrease levels of DPP-4

Question 40

When viewing the adrenal gland form external covering through the cortex in to the medulla, which one of the following is the correct order of hormone synthesis? A. Epinephrine, cortisol, dehydroepiandrosterone,(DHEA), aldosterone B. Aldosterone, cortisol, DHEA, epinephrine C. Cortisol, DHEA, epinephrine, aldosterone D. Aldosterone, DHEA, cortisol, epinephrine E. DHEA, aldosterone, epinephrine, cortisol

Answer 40

B. Aldosterone, cortisol, DHEA, epinephrine

Question 41

Drinking grapefruit juice while taking statins can lead to potentially devastating side effects. This is owing to a component of grapefruit juice doing which one of the following? A. interfering with hepatic uptake of statins B. Accelerating the conversion of the statin to a more toxic form C. Inhibiting the inactivation of statins D. Upregulating HMG CoA reductase E. Downregulating the HMG CoA reductase

Answer 41

C. Inhibiting the inactivation of statins

Question 42

Which one of the following are characteristics of cytochrome P450 enzymes is correct? A. They are all found in the Golgi apparatus and are referred to as microsomal enzymes B. They all contain a flavin-containing reductase unit that uses NADH and not NADPH as a source of electrons C. They are all inducible by oxygen, which binds to the iron of the cytochrome D. They all oxidize the substrate on which they act. E. They all generate a free-radical compound as a final product of the reaction

Answer 42

D. They all oxidize the substrate on which they act.

Question 43

Fairly predictable changes occur in the various metabolic pathways of lipid metabolism in patients with moderately advanced hepatocellular disease. Which one of the following changes would you expect to see under these conditions? A. The activity of plasma LCAT is increased B. Serum cholesterol esters are increased C. HTGL activity is increased D. Serum triacylglycerol levels are increased E. Serum NEFA levels are decreased.

Answer 43

D. Serum triacylglycerol levels are increased

Question 44

After 2-week alcoholic binge, Ms. T. ingested some acetaminophen to help her with a severe headache. She took three times the suggested dose because of the severity of the pain. Within 24 hours, Ms. T. became very lethargic , vomited frequently, and developed severed abdominal pain. The symptoms Ms. T. is experiencing are attributable to a reaction to the acetaminophen caused by which one of the following? A. The hypoglycemia experienced by the patient B. Ethanol-induced inhibition of acetaminophen metabolism C. The hyperglycemia experienced by the patient D. Ethanol-induced acceleration of acetaminophen metabolism E. Acetaminophen inhibition of VLDL secretion by the liver

Answer 44

D. Ethanol-induced acceleration of acetaminophen metabolism

Question 45

An individual displays impaired glucose tolerance; blood glucose levels remain elevated after a meal for a longer time than is normal, although they do eventually go down to fasting levels. Hepatocytes obtained from the patient display normal levels of insulin binding to its receptor. Analysis of glucose-6-phsophate formation within the hepatocytes, however, indicates a much slower rate of formation than in hepatocytes obtained from a normal control. A possible mutation that could lead to these results is which one of the following? A. A decrease in the Km of glucokinase B. An increase in the Vmax of glucokinase C. A nonfunctional glucokinase-regulatory protein D. An increase in the hexokinase activity E. A decrease in the hexokinase activity

Answer 45

C. A nonfunctional glucokinase-regulatory protein

Question 46

``` Individuals with cirrhosis frequently display elevated levels of amino acids in the blood. The source of these amino acids is predominantly which one of the following? A. red blood cell turnover B. Live protein turnover C. Enterocyte degradation and turnover D. Muscle protein turnover E. Plasma protein turnover ```

Answer 46

D. Muscle protein turnover

Question 47

``` Phase I reactions for xenobiotic detoxification require a reduced cofactor to donate electrons to oxygen as one atom of oxygen is incorporated into the substrate and the other atom of oxygen is incorporated into water. The reduced cofactor for the phase I reactions is derived primarily from which one of the following pathways? A. Hexose monophosphate shunt B. Glycolysis C. Fatty acid synthesis D. TCA recycle E. Fatty acid oxidation ```

Answer 47

A. Hexose monophosphate shunt

Question 48

``` A patient with chronic alcoholism presents to his physician with complaints of lethargy. Physical exam displays a malnourished individual with yellow sclera. Bloodwork indicates elevation of prealbumin, AST and ALT. The yellow sclera is most likely caused by which one of the following? A. Reduction in amino acid metabolism B. Reduction in glycosylation reactions C. Reduction in fatty acid oxidation D. Reduction in VLDL production E. Reduction in urea synthesis ```

Answer 48

B. Reduction in glycosylation reactions

Question 49

Liver disease exhibits which of the following? Choose the one best answer. See book for table.

Answer 49

``` F. Elevated blood levels of ALT and AST-Yes Elevated blood levels of bilirubin-Yes Elevated levels of blood clotting factors-No Edema-Yes Elevated blood levels of ammonia-Yes ```

Question 50

``` A person with chronic alcoholism has developed cirrhosis of the liver. The liver is filled with a type of collagen that interferes with appropriate liver function. Under these conditions, which liver cell type has been stimulated to produce fibril-producing collagen? A. Kupffer cells B. Stellate cells C. Endothelial cells D. Hepatocytes E. Pit cells ```

Answer 50

B. Stellate cells