week 1 textbook practice problems

A dietitian is counseling a patient with celiac sprue (intolerance to gluten, leading to malabsorption issues in the intestine) and describing a diet with appropriate carbohydrate, fat, and protein content. Once properly absorbed, the major fate, during respiration, of these compounds is which ONE of the following?

A. They are stored as triacylglycerols.

B. They are oxidized to generate ATP.

C. They release energy principally as heat.

D. They combine with CO2 and H2O and are stored.

E. They combine with other dietary components in anabolic pathways.

They are oxidized to generate ATP.

A dietitian is counseling a patient with celiac sprue (intolerance to gluten, leading to malabsorption issues in the intestine) who has experienced steatorrhea (fatty stools caused by poor absorption of dietary lipids in the intestine) for a number of years. The dietitian, in addition to listing appropriate carbohydrates, lipids, and proteins that will not trigger the malabsorption issue, encourages the patient to take certain vitamins. Which

ONE of the following vitamins is most likely on this list?

A. Vitamin C

B. Vitamin B3

C. Vitamin B2

D. Vitamin A

E. Vitamin B1

Vitamin A

Mrs. Jones is a sedentary 83-year-old woman who is 5 ft 4 in tall and weighs 125 lb. She has been at this weight for about a year. She says that a typical diet for her includes a breakfast of toast (white bread, no butter), a boiled egg, and coffee with cream. For lunch, she often has a cheese sandwich (white bread) and a glass of whole milk. For supper, she prefers cream of chicken soup and a slice of frosted cake. Mrs. Jones’s diet is most likely to be inadequate in which one of the following?

A. Vitamin C

B. Protein

C. Calcium

D. Vitamin B12

E. Calories

Vitamin C

A patient is trying to lose weight and wonders what her ideal number of calories per day might be. A dietitian is helping her by estimating the BMR, the DIT, and physical activity. The BMR is best estimated by consideration of which one of the following?

A. It is equivalent to the caloric requirement of our major organs and resting muscle.

B. It is approximately equivalent to the amount of physical activity.

C. It is approximately equivalent to the DIT.

D. It is dependent on the external humidity.

E. It is approximately equivalent to the DEE.

It is equivalent to the caloric requirement of our major organs and resting muscle

A friend of yours has decided to go on a crash diet, consuming only 700 calories/day. You advise your friend that he is at risk for certain dietary deficiencies and inform him of RDA, which is best described by which one of the following?

A. The average amount of a nutrient required each day to maintain normal function in 50% of the U.S. population

B. The average amount of a nutrient ingested daily by 50% of the U.S. population

C. The minimum amount of a nutrient ingested daily that prevents deficiency symptoms

D. A reasonable dietary goal for the intake of a nutrient by a healthy individual

E. A reasonable dietary goal for the intake of a nutrient as based on studies with laboratory animals and extrapolated to humans

A reasonable dietary goal for the intake of a nutrient by a healthy individual

A 35-year-old sedentary male patient weighing 120 kg was experiencing angina (chest pain) and other signs of coronary artery disease. His physician, in consultation with a registered dietitian, conducted a 3-day dietary recall. The patient consumed an average of 585 g of carbohydrate, 150 g of protein, and 95 g of fat each day. In addition, he drank 45 g of alcohol. The patient’s diet is best described by which one of the following?

A. He consumed between 2,500 and 3,000 kcal/day.

B. He had a fat intake within the range recommended in current dietary guidelines.

C. He consumed 50% of his calories as alcohol.

D. He was deficient in protein intake.

E. He was in negative caloric balance.

He had a fat intake within the range recommended in current dietary guidelines

A sedentary male weighing 75 kg is trying to lose weight and has begun a calorie-restricted diet. He has reduced his daily intake by 10 g of carbohydrates, 10 g of fat, 10 g of protein, and 10 g of ethanol. By what percentage has this man reduced his daily intake as compared to what he would require maintaining his current weight?

A. 5%

B. 10%

C. 15%

D. 20%

E. 25%

10%

A 45-year-old man developed deep vein thrombosis and subsequently a pulmonary embolism. The patient, after recovery, was placed on warfarin to prevent future blood clots. The patient was counseled by a dietitian to limit his consumption of which one of the following foods, owing to the finding that eating the food could interfere with the action of warfarin?

A. Egg yolks

B. Yellow vegetables

C. Citrus fruits

D. Green leafy vegetables

E. Skinless chicken

Green leafy vegetables

A 25-year-old female with Hashimoto thyroiditis is being treated with thyroid hormone replacement and is now euthyroid. She wishes to lose some of the weight she gained while she was in a hypothyroid state. In order to help her lose weight, her dietitian must determine her DEE in order to design a diet with fewer calories than her DEE. The patient weighs 70 kg, is moderately active (1 to 2 hours of exercise 5 days a week), and is currently consuming 2,700 calories/day. If the patient is to lose 1 lb per week, she would need to reduce her daily consumption by how many calories per day?

A. 200

B. 400

C. 600

D. 800

E. 1,000

800

A patient with cirrhosis is having mental status changes owing to elevated ammonia levels in his blood. In prescribing a diet to reduce ammonia production in this patient, which type of nutrient should be most restricted?

A. Ethanol

B. Lipids

C. Proteins

D. Carbohydrates

E. Water-soluble vitamins

Proteins

A 38-year-old male had just completed his annual physical exam. His physician told him that his daily caloric intake (as estimated from a 3-day dietary history the man had completed prior to the physical exam), coupled with his calculated DEE, would lead to a weight gain of 1.5 lb per month. The patient was advised to make some dietary changes to prevent this from happening. In order to maintain his current weight, the patient was advised to reduce his current daily dietary intake by which one of the following?

A. 25 g of carbohydrate

B. 20 g of protein

C. 20 g of fat

D. 10 g of ethanol

E. 10 g of carbohydrate and 10 g of ethanol

20 g of fat

A 50-year-old woman has visited her physician owing to tiredness and a persistent tingling in her hands and feet. The patient had switched to a strict vegan diet 3 years ago and had avoided all meat and dairy products since then. She also does not take any dietary supplements as she was convinced her healthy diet should be sufficient for her needs. An analysis of her blood demonstrated a reduced red blood cell number (anemia) along with the presence of some very large cells (megaloblasts). The woman was most likely deficient in which one of the following vitamins?

A. B1

B. B2

C. B3

D. B6

E. B12

B12

A well-balanced diet contains a certain percentage of calories as carbohydrate, fat, and protein, along with vitamins and minerals. Which one of the following does not contain molecules that are essential for the human diet?

A. Carbohydrate

B. Fat

C. Protein

D. Vitamins

E. Minerals

Carbohydrate

A patient with celiac sprue (intolerance to gluten, leading to malabsorption issues in the intestine) needs advice on which foods should be ingested and in what proportions, as the diet must contain all essential nutrients. When the patient eats and digests a mixed meal (containing carbohydrates, lipids, and proteins), which one of the following is most likely to occur?

A. Starch and other polysaccharides are transported to the liver.

B. Proteins are converted to dipeptides, which enter the blood.

C. Dietary triacylglycerols are transported in the portal vein to the liver.

D. Monosaccharides are transported to adipose tissue via the lymphatic system.

E. Glucose levels increase in the blood.

Glucose levels increase in the blood.

A marathon runner is training for a race. Two days before the race the runner exhausts her glycogen stores through an extensive training session, and then goes out and eats a large helping of pasta, a process known as “carb loading.” This process is designed to do which ONE of the following?

A. Induce the release of glucagon from the pancreas

B. Release insulin to stimulate glucose entry into the nervous system

C. Stimulate glycogen synthesis in liver and muscles

D. Stimulate the oxidation of glucose to carbon dioxide in the muscle

E. Stimulate red blood cell production of carbon dioxide from glucose

Stimulate glycogen synthesis in liver and muscles

Elevated levels of chylomicrons were measured in a patient’s blood. To lower chylomicron levels most effectively, you would prescribe a diet that is restricted in which one of the following?

A. Overall calories

B. Fat

C. Cholesterol

D. Starch

E. Sugar

Fat

An adult male patient exhibited a BMI of 33 kg/m 2 and a waist circumference of 47 in. What nutrition therapy would be most helpful?

A. Decreased intake of total calories because all fuels can be converted to adipose tissue triacylglycerols

B. The same amount of total calories, but substitution of carbohydrate calories for fat calories

C. The same amount of total calories, but substitution of protein calories for fat calories

D. A pure-fat diet because only fatty acids synthesized by the liver can be deposited as adipose

triacylglycerols

E. A limited food diet, such as the ice cream and sherry diet

Decreased intake of total calories because all fuels can be converted to adipose tissue triacylglycerols

A 2-month-old baby is exclusively breastfed. Which ONE of the following anatomic locations contains the most important enzyme this baby needs for the absorption of carbohydrates from this diet?

A. Salivary gland

B. Pancreas

C. Stomach

D. Small intestine

E. Liver

Small intestine

A “lipid panel” is ordered for a patient as a screening tool to help determine cardiovascular disease risk. The patient is told to fast for 12 hours before the blood draw such that which ONE of the following would be in significantly reduced amounts in the blood?

A. Cholesterol

B. Triacylglycerol

C. Serum albumin

D. Chylomicrons

E. Fatty acids

Chylomicrons

A patient with type 2 diabetes mellitus takes his insulin injection, and then 15 minutes later ingests a meal of bread, potatoes, and milk. Which ONE of the following proteins is suppressed during the absorption of this meal?

A. Glucagon

B. Insulin

C. Salivary amylase

D. Pancreatic amylase

E. Lactase

Glucagon

An athlete is competing in a 400-meter dash. Which ONE of the following is the major source of energy for the muscles used in this competition?

A. Muscle glycogen stores

B. Muscle triacylglycerol stores

C. Muscle amino acid oxidation

D. Lactic acid from the red blood cells

E. Liver triacylglycerol stores

Muscle glycogen stores

A 32-year-old woman has had episodes of dizziness and feeling faint. During one such episode she was taken to the Emergency Department of the local hospital and a blood test indicated significantly elevated levels of insulin, despite the woman having neither eaten for three hours nor injected insulin. Subsequent imaging studies led to the finding of a pancreatic tumor that would episodically release large amounts of insulin into the circulation (an insulinoma). The finding of the insulinoma would explain the patient’s symptoms by which one of the following?

A. Increased glucose uptake from the blood by the muscle and fat cells

B. Decreased glucose uptake from the blood by the muscle and fat cells

C. Induction of hyperglycemia

D. Increased triglyceride formation in the liver

E. Reduced amino acid oxidation in the muscle

Induction of hyperglycemia

The synthesis of numerous neurotransmitters requires precursors that contain nitrogen. Such nitrogen- containing precursors are obtained from which one of the following dietary components?

A. Carbohydrates

B. Fats

C. Proteins

D. Vitamins

E. Minerals

Proteins

The drug orlistat inhibits pancreatic lipase activity in the small intestine. Individuals taking orlistat will display which one of the following in their blood after eating a meal?

A. Increased levels of chylomicrons

B. Increased levels of free fatty acids

C. Decreased levels of chylomicrons

D. Increased levels of glycerol

E. Decreased levels of glucose

Decreased levels of chylomicrons

A scientist was testing an experimental weight-loss drug designed to inhibit pancreatic amylase. In a clinical trial of this drug, a volunteer would be expected to have difficulty accomplishing which one of the following after eating a meal containing carbohydrate, lipids, and proteins?

A. Synthesizing chylomicrons

B. Converting proteins to amino acids

C. Synthesizing 2-monoacylglycerol

D. Digesting triacylglycerol

E. Synthesizing liver glycogen

Synthesizing liver glycogen

A hiker who has become lost on the Appalachian Trail has consumed the last of his rations and has only water to drink. By 24 hours after his last meal, which one of the following is most likely to occur?

A. Gluconeogenesis in the liver will be the major source of blood glucose.

B. Muscle glycogenolysis provides glucose to the blood.

C. Muscles convert amino acids to blood glucose.

D. Fatty acids released from adipose tissue provide carbon for the synthesis of glucose.

E. Ketone bodies provide carbon for gluconeogenesis.

Gluconeogenesis in the liver will be the major source of blood glucose.

A physician is treating a patient with type 1 diabetes who has neglected to take her insulin for 5 days. The patient demonstrates elevated blood glucose and ketone body levels. Ketone bodies are indirectly elevated owing to which one of the following?

A. Elevated glucose levels

B. Reduced blood urea nitrogen

C. Decreased fatty acid release from the adipocyte

D. Inhibition of liver oxidation of ketone bodies

E. Reduced muscle utilization of fatty acids

Elevated glucose levels

In a well-nourished individual, as the length of fasting increases from overnight to 1 week, which one of the following is most likely to occur?

A. Blood glucose levels decrease by approximately 50%.

B. Red blood cells switch to using ketone bodies.

C. Muscles decrease their use of ketone bodies, which increase in the blood.

D. The brain begins to use fatty acids as a major fuel.

E. Adipose tissue triacylglycerols are nearly depleted.

Muscles decrease their use of ketone bodies, which increase in the blood.

A hospitalized patient had low levels of serum albumin and high levels of blood ammonia. His creatinine– height index (CHI) was 98%. His BMI was 20.5. Blood urea nitrogen was in the normal range, consistent with normal kidney function. The diagnosis most consistent with these findings is which one of the following?

A. A loss of hepatic function (e.g., alcohol-induced cirrhosis)

B. Anorexia nervosa

C. Kwashiorkor (protein malnutrition)

D. Marasmus (protein–energy malnutrition)

E. Decreased absorption of amino acids by intestinal epithelial cells (e.g., celiac disease)

A loss of hepatic function (e.g., alcohol-induced cirrhosis)

Otto S., an overweight medical student (see Chapter 1), discovered that he could not exercise enough during his summer clerkship rotations to lose 2 to 3 lb per week. He decided to lose weight by eating only 300 kcal/day of a dietary supplement that provided half the calories as carbohydrate and half as protein. In addition, he consumed a multivitamin supplement. During the first 3 days on this diet, which statement best represents the state of Otto S.’s metabolism?

A. His protein intake met the Recommended Dietary Allowance (RDA) for protein.

B. His carbohydrate intake met the fuel needs of his brain.

C. Both his adipose mass and muscle mass decreased.

D. He remained in nitrogen balance.

E. He developed severe hypoglycemia.

Both his adipose mass and muscle mass decreased.

A pregnant woman is having an oral glucose tolerance test done to diagnose gestational diabetes. The test consists of ingesting a concentrated solution of glucose (75 g of glucose) and then having her blood glucose levels measured at various times after ingesting the sugar. Her test results come back normal. At what time after consuming the oral sugar solution will she have the highest blood glucose level?

A. Immediately

B. 1 Hour

C. 2 Hours

D. 3 Hours

E. 4 Hours

1 Hour

A patient with frequent sweating and tremors is diagnosed with “reactive hypoglycemia” and has been prescribed a small meal every 4 hours throughout the day. The patient most likely is impaired in carrying out which one of the following?

A. Glycogenesis of liver glycogen stores

B. Glycogenolysis of muscle glycogen stores

C. Glycogenolysis of liver glycogen stores

D. Glycogenesis of muscle glycogen stores

E. Glycogenesis of adipose tissue glycogen stores

Glycogenolysis of liver glycogen stores

An activist is on a hunger strike to bring attention to her cause, and she has only consumed H2O and vitamins for the past 5 days. Which ONE of the following organs/structures has begun to utilize ketone bodies as a major secondary fuel source?

A. Red blood cells

B. Brain

C. Liver

D. Heart

E. All of the above

Brain

You are evaluating a patient who has a mutation that hinders the ability to carry out liver glycogenolysis. One initial finding shortly after entering the fasting state in this patient would be which ONE of the following?

A. Hyperglycemia

B. Ketosis (elevated levels of ketone bodies)

C. Significantly increased urea synthesis

D. Reduced blood lactate levels

E. Hypoglycemia

Hypoglycemia

A prisoner has gone on a hunger strike, drinking only water. Careful monitoring of the prisoner demonstrated a drop in blood urea nitrogen during the second week of the fast. This occurred owing to which one of the following?

A. Enhanced glycogenolysis

B. Reduced ketone body formation

C. A decrease in the rate of gluconeogenesis

D. An increase in the rate of gluconeogenesis

E. Enhanced glucose metabolism in the brain

A decrease in the rate of gluconeogenesis

Questions 3.13 to 3.15 are based on the following case. You are evaluating a 24-year-old patient who has, in the past 3 months, experienced a drop in BMI from 19.0 to 16.7

What is the weight loss of the patient over this past 3 months?

A. 2.5 kg

B. 5.0 kg

C. 7.5 kg

D. 1. The patient is 1.8 m tall.0.0 kg

E. 12.5 kg

0.0 kg

Questions 3.13 to 3.15 are based on the following case. You are evaluating a 24-year-old patient who has, in the past 3 months, experienced a drop in BMI from 19.0 to 16.7

The patient, during the past 3 months, had switched to a diet that was almost totally lacking triglyceride—a high-protein high-carbohydrate diet for weight loss. Such a diet has the potential to lead to which one of the following unintended side effects?

A. Increased chylomicron formation

B. Vitamin A deficiency

C. Vitamin C deficiency

D. Fasting hypoglycemia between meals

E. Increased triglyceride formation as a result of the high-carbohydrate content of the diet

Vitamin A deficiency

A patient attempted suicide by ingesting 50 aspirin tablets. This led to a fairly severe metabolic acidosis. A decrease of blood pH from 7.5 to 6.5 would be accompanied by which one of the following changes in ion concentration?

A. A 10-fold increase in hydrogen ion concentration

B. A 10-fold increase in hydroxyl ion concentration

C. An increase in hydrogen ion concentration by a factor of 7.5/6.5

D. A decrease in hydrogen ion concentration by a factor of 6.5/7.5

E. A shift in the concentration of buffer anions, with no change in hydrogen ion concentration

A 10-fold increase in hydrogen ion concentration

A medical student is attempting to understand the buffering system of the human body and has set up the following experiment in the laboratory to help with their understanding. Consider a biochemical reaction that is taking place in a 0.1 M buffer. The initial pH is 7.4, and the pKa of the buffer is 7.2. If, in a final reaction volume of 1.0 mL, 10 μmoles of protons are generated, what would be the final pH of the solution?

A. 7.59

B. 7.25

C. 7.22

D. 7.20

E. 7.15

7.22

A patient with an enteropathy (intestinal disease) produced large amounts of ammonia (NH3) from bacterial overgrowth in the intestine. The ammonia was absorbed through the intestine into the portal vein and entered the circulation. Which of the following is a likely consequence of his ammonia absorption?

A. A decrease of blood pH

B. Conversion of ammonia to ammonium ion in the blood

C. A decreased concentration of bicarbonate in the blood

D. Kussmaul respiration

E. Increased expiration of CO2

Conversion of ammonia to ammonium ion in the blood

Which of the following physiologic/pathologic conditions is most likely to result in an alkalosis, provided the body couldn’t fully compensate?

A. Production of lactic acid by muscles during exercise

B. Production of ketone bodies by a patient with diabetes mellitus

C. Repeated vomiting of stomach contents, including HCl

D. Diarrhea with loss of the bicarbonate anions secreted into the intestine

E. An infection resulting in a fever and hypercatabolism

Repeated vomiting of stomach contents, including HCl

Laboratory tests on the urine of a patient identified the presence of methylmalonate (−OOC–CH(CH3)–COO−). Methylmalonate is best described as which one of the following?

A. A strong acid.

B. The conjugate base of a weak acid.

C. It is 100% dissociated at its pKa

D. It is 50% dissociated at the pH of the blood.

E. It is a major intracellular buffer.

The conjugate base of a weak acid.

A patient with influenza has a fever of 101.8°F orally. The excess heat is dissipated throughout the body via a substance that can be best described by which one of the following?

A. It is a dipolar molecule.

B. It is composed mostly of amino acids.

C. It is a weak acid.

D. It is a weak base.

E. It is composed mostly of carbohydrates.

It is a dipolar molecule.

A patient with hypertension is being treated with hydrochlorothiazide, a diuretic medication that can cause some dehydration and major intracellular electrolyte imbalances. Which one of the following electrolytes might be in imbalance under these conditions?

A. Na+

B. K+

C. Cl−

D. HCO3−

E. H2O

K+

A patient with panic attacks and hyperventilation is in respiratory alkalosis. The excess hydroxide ions were able to overcome which one of the following buffers that has the greatest buffering capacity in and near to normal blood pH?

A. Carbonic acid

B. Dihydrogen phosphate

C. Ammonium ion

D. Acetoacetic acid

E. Acetic acid

Dihydrogen phosphate

A patient is in early diabetic ketoacidosis. Which one of the following would this patient be expected to exhibit upon examination?

A. Excess fluid in the tissues of the lower extremity

B. Increased respiratory rate

C. Low blood glucose

D. Decreased respiratory rate

E. Decreased urine output as an attempt to preserve water

Increased respiratory rate

A patient with severe anemia (reduced number of red blood cells in circulation) has a decreased capacity to utilize the bicarbonate buffer system to help maintain blood pH in the normal range. Which one of the following statements best describes the reason for this decreased capacity?

A. The total amount of carbonic anhydrase in blood plasma is decreased in anemia.

B. The total amount of carbonic anhydrase in blood plasma is increased in anemia.

C. The total amount of carbonic anhydrase in red blood cells is decreased in anemia.

D. The total amount of carbonic anhydrase in red blood cells is increased in anemia.

E. The total amount of carbonic anhydrase in interstitial fluid is decreased.

F. The total amount of carbonic anhydrase in interstitial fluid is increased.

The total amount of carbonic anhydrase in red blood cells is decreased in anemia

Water is the solvent of life, yet it only dissociates to a small extent. What is the pKa of water?

A. 0.5

B. 3.5

C. 7.0

D. 10.7

E. 15.7

15.7

The amino acid glycine has been used as a buffer for a number of biochemical experiments. Glycine contains two ionizable groups, one with a pKa of 2.34, and the other with a pKa of 9.60. Glycine would be an effective buffer at which one of the following pH values?

A. 4.0

B. 6.0

C. 8.0

D. 9.0

E. 11.0

9.0

Consider a buffer that has a free amino group (X-NH2 ) with a pKa of 8.5. If the buffer is present at a 0.1 M concentration what percentage of the buffer is in the acid form at pH 8.0?

A. 25

B. 50

C. 60

D. 75

E. 90

75

The major source of metabolic acid in the body is carbon dioxide owing to its ability to be enzymatically converted to which one of the following?

A. Hydrochloric acid

B. Sulfuric acid

C. Acetoacetic acid

D. Carbonic acid

E. Butyric acid

Carbonic acid

Histidine is an amino acid with three ionizable groups, one of which has a pKa of 6.0. This group, when protonated, has a positive charge. If this ionizable group, within a protein, forms an ionic interaction with a negatively charged group, what would you predict would happen to the pKa of the histidine ionizable group?

A. Increase

B. Decrease

C. Stay the same

Increase

A component of a “lipid panel” for a patient are triglycerides, which are best described by which one of the following?

A. Contains a steroid nucleus

B. Three fatty acids esterified to sphingosine

C. Three fatty acids esterified to a polyol

D. Two fatty acids and a phosphate esterified to a sphingosine

E. Two fatty acids and a phosphate esterified to a polyol

Three fatty acids esterified to a polyol

A patient was admitted to the hospital emergency department in a coma. Laboratory tests found high levels of the compound shown below in her blood:

CH2OH–CH2–CH2–COO−

Based on its structure (and your knowledge of the nomenclature of functional groups), you identify the compound as which one of the following?

A. Methanol (wood alcohol)

B. Ethanol (alcohol)

C. Ethylene glycol (antifreeze)

D. β-Hydroxybutyrate (a ketone body)

E. γ-Hydroxybutyrate (the “date rape” drug)

γ-Hydroxybutyrate (the “date rape” drug)

A patient was diagnosed with a deficiency of the lysosomal enzyme α-glycosidase. The name of the deficient enzyme suggests that it hydrolyzes a glycosidic bond, which is best described as a bond formed via which one of the following?

A. Through multiple hydrogen bonds between two sugar molecules

B. Between the anomeric carbon of a sugar and an O–H (or N) of another molecule

C. Between two anomeric carbons in polysaccharides

D. Internal bond formation between the anomeric carbon of a monosaccharide and its own 5th carbon

hydroxyl group

E. Between the carbon containing the aldol or keto group and the α-carbon of the sugar

Between the anomeric carbon of a sugar and an O–H (or N) of another molecule

In the congenital disease galactosemia, high concentrations of galactose and galactitol accumulate in the blood. Based on their names, you would expect which one of the following statements to be correct?

A. Galactitol is an aldehyde formed from the keto sugar galactose.

B. Galactitol is the oxidized form of galactose.

C. Galactitol is the sugar alcohol of galactose.

D. Both galactose and galactitol are sugars.

E. Both galactose and galactitol would give a positive reducing sugar test.

Galactitol is the sugar alcohol of galactose

A patient was diagnosed with one of the types of sphingolipidoses, which are congenital diseases involving the inability to degrade sphingolipids. All sphingolipids have in common which one of the following?

A. A glycerol backbone

B. Ceramide

C. Phosphorylcholine

D. N-Acetylneuraminic acid (NANA)

E. A steroid ring structure to which sphingosine is attached.

Ceramide

In diabetic ketoacidosis, metabolic acidosis results from increased hepatic production of ketone bodies (β- hydroxybutyrate, acetoacetate, and acetone). Which one of the following terms best describes all three of these ketone bodies?

A. Butyl structure

B. Aromatic structure

C. Aliphatic structure

D. Hydroxyl-containing structure

E. Amine-containing structure

Aromatic structure

A patient has had viral gastroenteritis for three days and has been unable to keep any oral intake down, such that the patient is now dehydrated. In the emergency department, he is given 2 L of IV D5 0.9% NaCl solution. Which of the following best describes this IV solution?

A. It is hypotonic.

B. It is hypertonic.

C. It contains D-glucose.

D. It contains L-glucose.

E. It contains D-galactose.

It contains D-glucose.

A patient with hyperlipidemia has been counseled to reduce the saturated fats in his diet, so he has replaced butter with a butter substitute that he knows is made from a polyunsaturated oil. The manufacturer of this butter substitute has partially hydrogenated this product. Which one of the following is the best description of why this product was partially hydrogenated?

A. The trans fatty acids produced by commercial hydrogenation are very healthy in humans.

B. Hydrogenation reduces the double bonds creating a more saturated product, which is more marketable.

C. Hydrogenation makes the product less expensive to produce.

D. Hydrogenation reduces the cholesterol content of the oil.

E. Hydrogenation increases the cholesterol content of the oil.

Hydrogenation reduces the double bonds creating a more saturated product, which is more marketable.

A researcher is trying to design an antibiotic to kill bacteria but not harm any human cells. Which one of the following theoretically could be utilized for this purpose?

A. A medication that inhibits reactions using only D-amino acids

B. A medication that inhibits reactions using only L-amino acids

C. A medication that inhibits reactions using only amino acids containing a β-amino group

D. A medication that inhibits reactions using only amino acids containing a γ-amino group

E. A medication that only inhibits reactions using only aromatic amino acids.

A medication that inhibits reactions using only D-amino acids

When D-glucose enters cells, it is rapidly phosphorylated to form glucose 6-phosphate. The bond created in this step is best referred to as which one of the following?

A. An ester linkage

B. An amide linkage

C. A phosphoester linkage

D. A phosphoanhydride linkage

E. A thioester linkage

A phosphoester linkage

D-erythrose, a 4-carbon aldose sugar.

How many asymmetric carbons are present in D-erythrose?

A. 0

B. 1

C. 2

D. 3

E. 4

2

D-erythrose, a 4-carbon aldose sugar.

How many potential stereoisomers are there in D-erythrose?

A. 1

B. 2

C. 4

D. 8

E. 16

4

β-D-Glucuronic acid can participate in which one of the following as compared to its precursor, β-D-glucose?

A. Increased hydrophobicity

B. Increased vDW interactions

C. Ionic interactions

D. Hydrogen bonds

E. Increased α-1,6 glycosidic bond formation

Ionic interactions

Defects in glycosphingolipid degradation can lead to a variety of serious diseases. Glycosphingolipids are derived from which of the following?

A. Glycine, palmitic acid, and carbohydrates

B. Serine, palmitic acid, and a steroid

C. Glycine, serine, and carbohydrates

D. Serine, palmitic acid, and carbohydrates

E. Palmitic acid, carbohydrates, and a steroid

Serine, palmitic acid, and carbohydrates

Sickle cell anemia is caused by a single-nucleotide change in DNA that leads to the substitution of one amino acid (E6V) in the β-chain. This one change in the primary sequence leads to the ability of the deoxygenated form of HbS to form polymers. As the polymers grow in size, the shape of the red blood cell is altered to accommodate the chains of hemoglobin. Which one of the following primarily dictates the polymerization of deoxygenated HbS?

A. The peptide backbone

B. Ionic interactions

C. Hydrophobic interactions

D. Hydrogen bonds

E. Peptide bonds

Hydrophobic interactions

One of the main sources of nonvolatile acid in the body is sulfuric acid generated from the sulfur-containing compounds in ingested food or from the metabolism of the sulfur-containing amino acids. Which of the following amino acids would lead to sulfuric acid formation?

A. Cysteine and isoleucine

B. Cysteine and alanine

C. Cysteine and methionine

D. Methionine and isoleucine

E. Isoleucine and alanine

Cysteine and methionine

Dianne A.’s different preparations of insulin contain some insulin complexed with protamine that is absorbed slowly after injection. Protamine is a protein preparation from rainbow trout sperm containing arginine-rich peptides that bind insulin. Which one of the following provides the best explanation for complex formation between protamine and insulin?

A. Arginine is a basic amino acid that binds to negatively charged amino acid side chains in insulin.

B. Arginine is a basic amino acid that binds to the α-carboxylic acid groups at the N-terminals of insulin

chains.

C. Arginine is a large, bulky hydrophobic amino acid that complexes with leucine and phenylalanine in

insulin.

D. Arginine forms disulfide bonds with the cysteine residues that hold the A and B chains together.

E. Arginine has a side chain that forms peptide bonds with the carboxyl terminals of the insulin chains.

Arginine is a basic amino acid that binds to negatively charged amino acid side chains in insulin.

Phosphorylation of proteins is an important component of signal transduction. Protein kinases phosphorylate proteins only at certain hydroxyl groups on amino acid side chains. Which of the following groups of amino acids contain side-chain hydroxyl groups and could be a potential substrate for such a protein kinase?

A. Aspartate, glutamate, and serine

B. Serine, threonine, and tyrosine

C. Threonine, phenylalanine, and arginine

D. Lysine, arginine, and proline

E. Alanine, asparagine, and serine

Serine, threonine, and tyrosine

A protein’s activity is altered when a particular serine side chain is phosphorylated. Which of the following amino acid substitutions at this position could lead to a permanent alteration in normal enzyme activity?

A. S → E

B. S → T

C. S → Y

D. S → K

E. S → L

S → E

Proteins, which are composed of amino acids, help transport lipids in the bloodstream. These proteins need to be able to cluster with other nonpolar molecules and exclude water. Which of the following would best describe the side chains of these amino acids in the lipid transport proteins?

A. A more positive hydropathic index

B. A more negative hydropathic index

C. A neutral hydropathic index

D. A pKa of the primary carboxylic acid group of approximately 2

E. A pKa of the α-amino group of approximately 9.5

A more positive hydropathic index

A patient with high cholesterol begins taking a statin medication and develops myalgias (muscle soreness and aches). The physician orders CK (creatine kinase) levels to check for muscle damage, a known side effect of statins. Lab results show a higher than normal level of CK-MM. Which one of the following best describes CK-MM?

A. Heterodimer

B. Isozyme

C. Produced by the brain

D. Produced by the heart

E. Produced by the liver

Isozyme

All of the amino acids that are used to synthesize human proteins (with the exception of glycine) have which one of the following in common?

A. An aromatic group

B. A hydroxyl group

C. An asymmetric carbon in the D-configuration

D. An asymmetric carbon in the L-configuration

E. An asymmetric β-carbon

An asymmetric carbon in the L-configuration

A patient with recurrent kidney stones is found to have an inherited amino acid substitution in a transport protein that reabsorbs certain amino acids from the glomerular filtrate so they are not lost in the urine.

Which of the following amino acid groups are not reabsorbed from the glomerular filtrate in this disease

process?

A. Cysteine, methionine, and arginine

B. Cysteine, methionine, and lysine

C. Cysteine, arginine, and lysine

D. Methionine, arginine, and lysine

E. Methionine, arginine, and histidine

Cysteine, arginine, and lysine

A patient with recurrent kidney stones is found to have an inherited amino acid substitution in a transport protein that reabsorbs certain amino acids from the glomerular filtrate so they are not lost in the urine.

Which one of the following amino acids is most responsible for this patient’s recurrent kidney stones?

A. Cysteine

B. Methionine

C. Arginine

D. Lysine

E. Histidine

Cysteine

A protein loses activity with a V96L mutation. Activity can be restored to the protein by introducing a second mutation, V172A. The most likely possible explanation for this finding is which one of the following?

A. Substitution of one hydrophilic residue for another restores activity

B. The V96L mutation disrupts an ionic interaction stabilizing the protein structure, whereas the V172A mutation allows restoration of the ionic interaction

C. The V96L mutation disrupted hydrogen bond stabilization of the structure, whereas the V172A mutation allowed restoration of the hydrogen bond interactions

D. The V96L mutation introduced steric hindrance into the structure, whereas the V172A relieved the steric hindrance introduced by the first mutation

E. The V96L mutation disrupted a disulfide bond, whereas introducing the V172A mutation allowed the disulfide bond to re-form

The V96L mutation introduced steric hindrance into the structure, whereas the V172A relieved the steric hindrance introduced by the first mutation

The enzyme that catalyzes the first step in glycolysis converts glucose to glucose 6-phosphate. The liver form of this enzyme is encoded by a different gene than the muscle form of this enzyme. The different forms of the enzyme can best be described as which one of the following?

A. Isomers

B. Epimers

C. Stereoisomers

D. Isozymes

E. Mirror images

Isozymes

An enzyme has an aspartic acid side chain, which is critical for enzyme activity. The pH optimum of the enzyme is 5.5, and studies have shown that at pH 5.5 this critical aspartic acid side chain is in its protonated state. This can occur due to which one of the following?

A. The aspartic acid side chain is in a hydrophobic environment within the protein.

B. The aspartic acid side chain is surrounded by K and R amino acid side chains.

C. The pKa for this aspartic acid side chain is reduced by the structure of the enzyme.

D. The aspartic acid side chain is stabilized by ionic interactions within the protein.

E. The aspartic acid side chain is involved in hydrogen bond formation with L and V side chains.

The aspartic acid side chain is in a hydrophobic environment within the protein.

Protein X (156 amino acids long) is normally targeted to the membrane via a posttranslational modification. A variant of X has been studied that lost the ability to be translocated to the membrane, and the protein is instead targeted for degradation within the endoplasmic reticulum. Which of the following mutations could lead to these findings?

A. S55L

B. N62R

C. C153S

D. Y154F

E. L15V

C153S

A local hospital is treating a patient with the symptoms of excessive insulin release into the blood. A method to determine if the patient took an insulin overdose would be to measure which one of the following in the patient’s blood?

A. The A-peptide of insulin

B. The B-peptide of insulin

C. The C-peptide of insulin

D. The levels of zinc ions

E. The levels of calcium ions

The C-peptide of insulin