What element is found in proteins but not in carbohydrates and fats?
In comparison to the composition of carbohydrates and fats, which element found in proteins makes them unique?
Which of the following is the primary factor that differentiates one amino acid from another?
The side group
Which of the following elements is found in certain amino acids?
Terms used to classify amino acids in the diet include all of the following except
How many different kinds of amino acids make up proteins?
All of the following are contained in an amino acid except
an aldehyde group.
Approximately how many different amino acids are used in the synthesis of body proteins?
What is the simplest amino acid?
Which of the following is not an essential amino acid in human nutrition?
Any of the following can be used by the body for the synthesis of a nonessential amino acid except
an essential mineral.
What amino acid is classified as conditionally essential when dietary intake of phenylalanine is insufficient or the body cannot normally metabolize phenylalanine?
Which of the following is a feature of an essential amino acid?
It must be supplied by the diet
What type of reaction is required to bind two molecules of glycine together and release a molecule of water?
When two amino acids are chemically joined together, the resulting structure is called a
What is the composition of a tripeptide?
Three amino acids bonded together
What is meant by the amino acid sequence of a protein?
Order of amino acids in the peptide chain
A dispensable amino acid is one that
can be synthesized by the body.
In comparison to the well-defined structure of starch, which of the following is the most important factor that allows for the synthesis of thousands of different proteins?
Number of different amino acids
Which of the following would be classified as a polypeptide?
20 amino acids bonded together
The following amino acids are linked together: glycine-lysine-valine. This compound is a
The weak electrical attractions within polypeptide chains account for the protein's
Which of the following is a feature of hemoglobin?
It is constructed of 4 polypeptide chains
An example of a protein with quaternary polypeptide structures is
What is the process by which heat or acidity disrupts the normal shape of a protein chain?
The application of heat or acid to a protein that causes its shape to change is known as
What process results in the hardening of an egg when it is exposed to heat?
After a hamburger is eaten, in what organ is the hydrolysis of its proteins initiated?
What is the name of the inactive form of the protein-splitting enzyme in the stomach?
In what organ is pepsin active?
What digestive enzyme would be most affected in people who are unable to produce hydrochloric acid?
Protein-hydrolyzing enzymes are commonly known as
The function of a protease is to
What is the chief function of pepsin?
Cleaves proteins into smaller polypeptides
What percentage of dietary protein is hydrolyzed in the mouth?
Pepsinogen is also known as a(n)
After digestion of proteins, what products are absorbed into the circulation?
Free amino acids, and a few dipeptides and tripeptides
What is the usual fate of orally ingested enzyme supplements?
Digested by gastrointestinal proteases
What is an oligopeptide?
A string of about 4-9 amino acids
Which of the following statements is not characteristic of enzymes?
They are involved in synthesis reactions only
Which of the following describes the structure of pepsin?
All of the following are fates of amino acids in the intestinal tract except
some may be used for synthesis of gastric protease.
Of the following sources of amino acids, which would be best absorbed in normal, healthy people?
Your cousin Wanda was born with a genetic defect affecting her digestion, namely, a lack of intestinal villus tripeptidases and dipeptidases. Which of the following digestive
Peptides → amino acids
Approximately how many different proteins are present in the human body?
Which of the following describes a process in protein synthesis?
The code to make a protein is carried by a strand of messenger RNA
Which of the following is a characteristic of protein synthesis?
Messenger RNA is constructed from a DNA template to carry instructions
The process whereby messenger RNA is made from a DNA template is
What is a ribosome?
A structure upon which proteins are assembled
All of the following are features of protein in nutrition except
most of the body's thousands of proteins have been studied and characterized.
Your college dormitory roommate, James, told you that he's had anemia for quite some time and that it's from having abnormally-shaped hemoglobin. What type of anemia does James have?
A common genetic variation which causes a change in the amino acid sequence in the structure of hemoglobin leads to the disease
Which of the following is characteristic of sickle-cell anemia?
he abnormal structure of the hemoglobin alters the shape of the red blood cell
What is the structure of an enzyme?
What protein is intimately involved in the formation of scar tissue in wound healing?
What type of protein would the body make in order to heal a wound?
Which of the following is a characteristic of hormones?
Act as messenger molecules
Which of the following do(es) not function as a transport protein?
What is the relationship between body proteins and water?
Proteins attract water
All of the following describe associations between protein nutrition and the body's water balance except
excessive protein losses by the kidney may lead to dehydration.
The conditions known as acidosis and alkalosis refer to a disruption of the body's
Tissue swelling that results from water accumulating between cells is known as
Proteins, because they attract hydrogen ions, can act as
What function does a buffer perform?
Helps maintain a constant pH
Which of the following processes is regulated primarily by the buffering action of proteins?
How do sodium and potassium travel into and out of cells?
There are transport proteins within the cell membrane that pick up and release the minerals across the membrane
What is opsin?
A light-sensitive protein
Which of the following proteins inactivates foreign bacteria and viruses?
The body's usual response to detection of antigens is to synthesize
Which of the following describes the structure of an antibody?
Huge protein molecule
Which of the following is involved in the clotting of blood?
How many grams of nitrogen are contained in a 2500-kcalorie diet that provides 15% of the energy as protein?
Which of the following may be used to determine protein utilization?
When nitrogen taken into the body exceeds nitrogen losses, we say the person is in
positive nitrogen balance.
Which of the following defines protein turnover?
The sum of protein synthesis and degradation
What is the amino acid pool?
A mix of essential and nonessential amino acids derived from protein breakdown and dietary protein intake
Which of the following describes the state of nitrogen balance for a normal, healthy 35-year-old person who weighs 60 kg and consumes a diet that provides 75 g of protein and adequate energy?
The body's amino acid pool consists of
both essential and nonessential amino acids.
What is the nitrogen balance of a person who consumed a 3500-kcalorie diet containing 10% protein and excreted a total of 12 grams of nitrogen?
Which of the following would describe the state of nitrogen balance of a person who ingested 16 g of food nitrogen and lost 19 g of nitrogen?
What is the usual state of nitrogen balance for healthy infants, children, and pregnant women?
What amino acid is used to synthesize the neurotransmitter serotonin and the vitamin niacin?
What is meant by protein turnover?
The synthesis and degradation of body proteins
What is the fate of excess dietary protein?
After absorption, the extra amino acids will be rapidly degraded
When amino acids are deaminated, the immediate products are ammonia and often a
Protein sparing in the body is best achieved when a person ingests
adequate levels of carbohydrate and fat.
A person who is starving is losing
glycogen, protein, and fat.
Which of the following illustrates a deamination reaction?
Removal of the amino group from an amino acid
Which of the following is the most likely side effect of a high-protein, low-carbohydrate diet?
Which of the following compounds does not contain nitrogen?
Which of the following is a consequence of excess protein intake?
Increased production and excretion of urea
Which of the following are precursors of urea synthesis?
All amino acids
What is the process whereby an amino group is combined with a keto acid to form an amino acid?
In the metabolism of amino acids for energy, what is the fate of the amino group?
Excreted as urea
The body's need for water increases on a diet high in
What is the most likely reason for a person to have abnormally high blood ammonia levels?
Jason is 35 years old and was recently diagnosed with 2 failing kidneys. He was advised to decrease the amount protein he consumes. If Jason cheats by eating an 8-ounce steak for dinner tonight, shortly thereafter there would most likely be an increase in the urea levels of his
What is the most likely reason for having an abnormally high blood urea level?
A prominent result of transamination reactions is the synthesis of
nonessential amino acids.
Your father, who has a high blood ammonia concentration, most likely has a poorly functioning
Your mother, who has a high blood urea content, most likely has a poorly functioning
A reference protein equals or exceeds the essential amino acid requirements of all of the following population groups except
What is the percent digestibility of most plant proteins?
What is the percent digestibility of most animal proteins?
Which of the following food proteins has the best assortment of essential amino acids for the human body?
Which of the following is related to the quality of a food protein?
Essential amino acid balance
What primary factor governs the quality of a food protein?
Essential amino acid content
In the study of protein nutrition, what term describes the amount of amino acids absorbed from a given amount of protein consumed?
Which of the following is not considered to be a source of high-quality protein in human nutrition?
Which of the following animal-derived proteins is classified as a poor-quality protein?
What is a "limiting" amino acid in a protein?
An essential amino acid present in insufficient quantity for body protein synthesis to take place
If the diet is lacking an essential amino acid, what will be the course of action?
Protein synthesis will be limited
Which of the following could not be a limiting amino acid in the diet?
Alberta is a 20 year old who has been a vegetarian for 3 years. She comes to you for advice after reading some material online by the Meat Promoters of America organization. One of their statements is: ". . . vegetarians are at risk for protein deficiency because they cannot consume all of the essential amino acids necessary for healthy individuals." How should Alberta be advised?
Although many foods don't provide all the essential amino acids individually, she could consume complementary proteins throughout the day, which would provide all the essential amino acids she needs
Which of the following is characteristic of protein nutrition in vegetarians?
Most vegetarians eating a variety of foods need not balance essential amino acid intake at each meal
What is the Daily Value for protein based on a 2000-kcalorie intake?
What is complementary protein nutrition?
A strategy that combines plant proteins in the same day to improve the balance of essential amino acids
In general, the protein quality in grains would be most improved by the addition of a plant protein rich in
In general, the protein quality of legumes would be most improved by the addition of a plant protein rich in
Relative to animal proteins, which of the following amino acids is present in lesser amounts in proteins of legumes?
Approximately what percentage of children worldwide have protein-energy malnutrition?
Acute protein-energy malnutrition in children is characterized by
low weight for height.
Chronic protein-energy malnutrition in children is characterized by
short height for age.
All of the following are characteristics of protein-energy malnutrition except
it almost always exhibits overt signs.
Marasmus occurs most commonly in children of ages
You are reading a case study from a researcher at World University. The researcher has traveled to the largest city in India and is reporting on an illness present in a 15-month-old boy. The researcher described the child as extremely thin and bony, with wrinkled skin and enlarged fatty liver. For the past year, this child has subsisted almost entirely on diluted cereal drink. Your first thought is that all of these observations are characteristic of marasmus except for the
enlarged fatty liver.
Which of the following would you not expect to see in a person with kwashiorkor?
Increased physical activity
Which of the following is associated with the presence of tissue edema in kwashiorkor?
Low concentration of blood protein
Which of the following is not a characteristic of marasmus?
Affects brain development only minimally
Which of the following is a feature of malnutrition?
Dysentery is common and leads to diarrhea and nutrient depletion
At the end of your class presentation on "Protein-Energy Malnutrition," a student asks you to clarify how the rapid onset of protein-energy malnutrition occurs in kwashiorkor. How should you respond?
It is typically seen in patients who are 1-3 years old due to the sudden change in diet arising from their being weaned from breast milk after the birth of a sibling
What term describes the illness a child develops when the next child is born?
Which of the following conditions is associated with edema?
Diminished concentration of blood proteins and hormones, which causes fluid to leak from the blood vessels
Kwashiorkor typically develops in children of ages
n kwashiorkor, the loss of hair color is indirectly related to
inadequate intake of tyrosine.
In kwashiorkor, what mineral is often present in an unbound form that promotes bacterial growth?
What is the most likely explanation for the fatty liver that develops from protein deficiency?
Inability of the liver to synthesize lipoproteins for fat export
Which of the following is a feature of kwashiorkor?
It is typically precipitated in the undernourished child who has an infection
What is the usual initial therapy for the treatment of kwashiorkor?
Fluid balance restoration
Supplements of which of the following amino acids are reported to lower blood pressure and reduce homocysteine levels?
Excessive amounts of homocysteine in the blood are thought to increase the risk for
All of the following are known to raise homocysteine levels except
excess arginine intake.
What type of diet is advised to rehabilitate a severely malnourished child?
Which of the following is a feature of homocysteine?
It is increased in the blood of coffee drinkers
Which of the following describes a relationship between protein/amino acids and heart disease?
Elevated blood homocysteine levels are associated with smoking cigarettes and drinking alcohol
What ratio (mg:g) of calcium to protein intake is believed to promote optimal bone health?
Which of the following describes an association between protein intake and kidney function?
Restricting protein intake may slow the progression of kidney disease
In relation to the range of protein intake as a percentage of energy intake, what would be the highest safe level of protein intake for a 60-kg adult ingesting 2500 kcalories?
Which of the following describes a relationship between protein intake and calcium metabolism?
Calcium excretion rises with increasing intake of animal-derived proteins
What is the RDA for protein for a 48-kg woman?
What is the ratio of calcium to protein intake (mg to g) for most U.S. women?
What would be the primary principle of wise diet planning as related to protein nutrition?
Which of the following is a feature of the protein RDA?
The recommendations are generous
If protein needs are expressed per kilogram of body weight, which of the following describes the requirements of infants?
Greater than adults
What is the range of daily protein intake, in g/kg, recommended for athletes?
Your friend Jill has just joined her community college soccer team. How much protein should she consume each day?
Which of the following is an assumption made in the formulation of the RDA for protein?
Dietary carbohydrate and fat intakes are adequate
All of the following assumptions are made by the committee in setting the RDA for protein except
the fat content of the diet will be high.
Which of the following is a feature of protein nutrition?
The protein RDA assumes that dietary protein is from a mix of low- and high-quality sources
What is the percentage of total energy derived from protein in a diet containing 50 grams of protein and 2000 kcalories?
If a person consumes 65 grams of protein and a total of 2700 kcalories per day, approximately what percentage of energy would be derived from protein?
Approximately how many grams of protein are found in one quart of milk?
Which of the following is a feature of whey protein?
It is a waste product of cheese production
Jim, a college baseball player, tells you that he has started to take glutamine supplements. How would you advise him?
Since single amino acids do not occur naturally in foods, they offer no benefit to the body and may even be harmful
Which of the following is a feature of the branched-chain amino acids?
They may be helpful in treatment of advanced liver failure
What amino acid has been linked to the development of the rare blood disorder eosinophilia myalgia in people who took it as a supplement?
What amino acid supplement has been advertised in the popular media for treating herpes infections?
The disease phenylketonuria is related chiefly to abnormal metabolism of
a certain amino acid.
The study of how food interacts with genes is known as
The study of how environmental factors influence the expression of genes without altering the DNA is known as
Approximately what percentage of a person's genes are similar to that of an unrelated person?
What dispensable amino acid becomes essential in people with PKU?
The incidence of PKU in infants in the United States is one in every
All of the following are characteristics of phenylketonuria except
it is treated by total elimination of dietary phenylalanine.
Dietary restriction of phenylalanine combined with adequate tyrosine is the usual treatment for people born with the disorder
Which of the following describes the sum of all chemical reactions that go on in living cells?
In photosynthesis, the plant uses energy from the sun, plus water and carbon dioxide, to synthesize
A typical cell contains "powerhouses," which is another name for the
A feature of catabolic reactions is that they
involve release of energy.
What term is specific to reactions in which simple compounds are combined into more complex molecules?
The site of lipid synthesis in the cell is the
smooth endoplasmic reticulum.
Which of the following reactions is an example of an anabolic reaction?
Cholesterol synthesis from acetyl CoA molecules
The formation of glycogen by the liver cell is an example of
Which of the following is an example of a catabolic reaction?
Urea formation from an amino acid
All of the following are among the functions of the liver except
production of red blood cells.
What is the approximate percent efficiency of conversion of food energy to ATP energy in the body?
In the adult body, food energy not stored as fat or glycogen is lost as
Which of the following defines a coenzyme?
An organic molecule required for the functioning of an enzyme
The hydrolysis of ATP that often occurs simultaneously with the synthesis of many compounds is an example of
Which of the following metabolic reactions occurs when a cell uses energy?
ATP releases a phosphate group and becomes ADP
What is the major energy carrier molecule in most cells?
The basic units derived from food include all of the following except
Approximately what percentage of the body's energy expenditure is furnished by amino acids?
10 to 15
Which of the following can not be formed from acetyl CoA molecules?
Which of the following can not be formed from pyruvate in human beings?
Glycolysis is the conversion of
glucose to pyruvate.
The series of reactions involving the conversion of glucose to pyruvate is known as
Which of the following is not an aspect of glycolysis?
It is irreversible
Which of the following outlines the overall sequence of events in the complete oxidation of glucose?
Glycolysis, TCA cycle, electron transport chain
Which of the following is a feature of aerobic metabolism?
Energy is produced more slowly than in anaerobic metabolism
An aerobic reaction is one that requires
Your roommate Demetrius is participating in a weightlifting course and complains of a burning pain during workouts. You explain to Demetrius that the rapid breakdown of glucose in his muscles produces large amounts of pyruvate, which leads to a fall in pH within the muscle and that the muscle responds by converting excess pyruvate to
The Cori cycle involves the interconversion of
lactate and glucose.
When a person is performing intense physical exercise and begins to feel fatigue and a burning pain in the muscles, the response of the muscles is to synthesize more
Which of the following is not a possible fate of metabolized glucose?
Which of the following nutrients can be made from compounds composed of 2-carbon skeletons?
Which of the following is a possible fate of acetyl CoA?
Synthesis to fatty acids
What is the first product of fatty acid catabolism?
Fatty acid oxidation results in the direct production of
Production of excessive amounts of acetyl CoA molecules leads to the synthesis of
fatty acids only.
In a triglyceride that contains 54 carbon atoms, how many can become part of glucose?
Which of the following compounds cannot be formed from fatty acids?
Approximately what percentage of the weight of triglycerides cannot be converted to glucose?
What percentage (by weight) of a triglyceride molecule can be converted to glucose?
How many acetyl CoA molecules may be obtained from oxidation of an 18-carbon fatty acid?
Which of the following dietary components cannot be used to synthesize and store glycogen?
Which of the following cannot be used to make body proteins?
An immediate consequence of a cellular deficiency of oxaloacetate is a slowing of
the TCA cycle.
All of the following may serve as precursors for oxaloacetate synthesis except
What is the immediate fate of excess dietary protein in the body?
After digestion and absorption, an amino acid not used to build protein will first be subjected to
removal of its amino group.
Which of the following leads to the production of urea?
oxidation of amino acids
When energy-yielding nutrients are consumed in excess, which one(s) can lead to storage of fat?
Fat, carbohydrate, and protein
If the carbohydrate content of the diet is insufficient to meet the body's needs for glucose, which of the following can be converted to glucose?
When protein consumption is in excess of body needs and energy needs are met, the excess amino acids are metabolized and the energy in the molecules is
stored as glycogen and fat.
What are the products from the complete oxidation of fatty acids?
Water, carbon dioxide, and energy
In addition to energy, what are the principal end products of cellular oxidation of carbohydrates?
Water and carbon dioxide
Which of the following products is not generated via the TCA cycle or electron transport chain?
At what point is oxygen used in the electron transport chain?
At the end
Products from the electron transport chain pathway include all of the following except
Which of the following accounts for the higher energy density of a fatty acid compared with the other energy-yielding nutrients?
Fatty acids have a greater percentage of hydrogen-carbon bonds
The number of ATP molecules that can be produced from a molecule of protein, fat, or carbohydrate is generally related to the number of atoms of
Approximately how many molecules of ATP are generated from the complete oxidation of one molecule of glucose?
Approximately how many ATP molecules are synthesized from the complete oxidation of a molecule of palmitic acid?
Which of the following can be synthesized from all three energy-yielding nutrients?
Which of the following is the most likely explanation for the body's higher metabolic efficiency of converting a molecule of corn oil into stored fat compared with a molecule of sucrose?
There are fewer metabolic reactions for disassembling the corn oil and re-assembling the parts into a triglyceride for uptake by the fat cells
If a person consumes 100 kcalories in excess of energy needs from table sugar, approximately how many of the kcalories are stored in the body?
If a person consumes 100 kcalories in excess of energy needs from olive oil, approximately what percentage of the kcalories are stored in the body?
Jake is getting ready for spring training and is sitting down to a dinner of half a chicken, a rib-eye steak, black beans, and 5 slices of bacon. He has been eating typical dinners like this for about a month and has since gained 7 pounds, while exercising only briefly. When Jake asks why he doesn't see an increase in his biceps or abs, the proper response should be
dietary protein alone does not contribute to muscle accretion.
Which of the following is a characteristic of the metabolism of specific macronutrients?
The rate of fat oxidation does not change when fat is eaten in excess
How does excess carbohydrate intake contribute to obesity?
It spares oxidation of body fat and dietary fat
Which of the following is the body's first response to the absorption of abundant amounts of carbohydrate?
Synthesis and storage of glycogen
All of the following are features of the metabolism of surplus dietary carbohydrate in human beings except
excess glucose is oxidized only very slowly.
Which of the following is a feature of the metabolism of surplus dietary fat?
Excess fat is almost all stored
After the first day or so of fasting, which of the following is most depleted in the body?
Of the total amount of carbohydrate energy consumed by the body, approximately what percentage is used by the brain and nerve cells?
If a normal person expends 1200 kcalories while at rest, approximately how many are used by the brain?
During the first few days of a fast, what energy source provides about 90% of the glucose needed to fuel the body?
Which of the following dietary nutrients would most rapidly reverse a state of ketosis in a starving person?
How soon would death occur from starvation if the body was unable to shift to a state of ketosis?
Within 3 weeks
A feature of ketosis is that it
occurs when fats are partially oxidized
The effects on metabolism from starvation are similar to those from
A person said to have acetone breath most likely has the condition known as
Which of the following is used to supply some of the fuel needed by the brain only after the body has been fasting for a while?
Elizabeth has been fasting for 4 days in observance of her religious beliefs. You note that her breath smells "fruity." This is most likely due to
her body's shift to a state of ketosis.
Ketonemia is defined as an elevation of
ketones in the blood.
How are ketones formed?
Condensation of acetyl CoA molecules
All of the following are general features of starvation in people except
a decrease in mental alertness.
Which of the following is a characteristic of ketosis?
It may lead to a lowering of blood pH
Which of the following is classified as a ketone body?
Adverse side effects of typical low-carbohydrate diets include all of the following except
high blood pressure.
Lillie has been losing weight by following a very-low-carbohydrate diet for 2 months. Her primary care physician just diagnosed ketosis through a urine sample. Which of the following symptoms would be another way the physician might have suspected ketosis in Lillie?
Fruity odor on breath
A person with fruity odor on the breath demonstrates evidence of metabolic
What type of diet is associated with the development of ketosis?
The health benefits of moderate alcohol intake occur in people with a starting age (years) of
Binge drinking is defined as the successive consumption of
Which of the following defines a moderate level of alcohol intake per day for the average-sized woman?
Up to 1 drink
Which of the following defines a moderate level of alcohol intake per day for the average-sized man?
Up to 2 drinks
The chemical structure of ethanol consists of
2 carbons and 1 hydroxyl group
With alcohol beverages, the ratio of proof to alcohol percentage is
The amount of ethanol in a typical "drink" is
Approximately how many kcal are contained in 3 ounces of 80-proof rum?
One average-sized can of beer contains about the same amount of alcohol as
1½ ounces of vodka.
What is the percentage of ethanol in 120-proof scotch whiskey?