Chapter 25

Which of the following selections includes ONLY essential amino acids for a growing child?

leucine, lysine, valine, tryptophan, arginine

Lipids circulate through the bloodstream as __________.

lipoproteins and free fatty acids

Which of the following foods are DEFICIENT in dietary fiber?

milk and meat

NAD, a key coenzyme used in the process of producing ATP, is produced from which water-soluble vitamin?

niacin

A cell with excess carbohydrates, lipids, and amino acids will break down carbohydrates to __________.

obtain energy

In terms of the movement of electrons, the gain of electrons is called reduction, whereas the loss is called __________.

oxidation

In glycolysis, six-carbon glucose molecules are broken down into two three-carbon molecules of __________.

pyruvic acid

The four processes involved in heat exchange with the environment are __________.

radiation, conduction, convection, and evaporation

LDLs are absorbed by cells through the process of __________.

receptor-mediated endocytosis

Neurons must be provided with a reliable supply of glucose because they are __________.

usually unable to metabolize other molecules

Which of the following is a fat-soluble vitamin necessary for synthesis of visual pigments?

vitamin A

In resting skeletal muscles, a significant portion of the metabolic demand is met through the __________.

catabolism of fatty acids

Lucy, a 35-year-old woman, says she CANNOT lose the fat around her abdomen because it is brown fat. You correct her by saying that the only people with brown fat are __________.

infants

Before the large vitamin B12 molecule can be absorbed, it must be bound to __________.

intrinsic factor

The trace minerals found in extremely small quantities in the body include __________.

iron, zinc, copper, and manganese

An individual's basal metabolic rate ideally represents __________.

the minimum resting energy expenditure of an awake, alert person

In the beta-oxidation of an 18-carbon fatty acid molecule, the cell gains __________.

144 ATP

For each glucose molecule converted to two pyruvates, the anaerobic reaction sequence in glycolysis provides a net gain of __________.

2 ATP for the cell

For each glucose molecule processed during aerobic cellular respiration, the cell gains __________.

36 molecules of ATP

The efficiency rate for the complete catabolism of glucose is about __________.

42 percent

Which of the following are coenzymes that deliver hydrogen ions and electrons to the ETS in the inner mitochondrial membrane?

NADH and FADH2

Under normal circumstances, if you eat three meals a day, the body will spend approximately 12 hours in the __________

absorptive state

Why are minerals, vitamins, and water classified as essential nutrients?

The body cannot synthesize the nutrients in sufficient quantities.

Milk and eggs are complete proteins because they contain __________.

all the essential amino acids in sufficient quantities

Which of the following people would be in positive nitrogen balance?

athletes in training, a pregnant woman, and growing children

The first step in a sequence of enzymatic reactions in the tricarboxylic acid cycle is the formation of __________.

citric acid

Which of the following is a nitrogen compound important in energy storage in muscle tissue?

creatine

Which of the following is an important energy source during periods of starvation, when glucose supplies are limited?

free fatty acids

The synthesis of glucose from nonglucose precursors is known as __________.

gluconeogenesis

During open-heart surgery, which of the following thermoregulatory changes will be induced on the patient's body?

hypothermia

The most important factors in good nutrition are to obtain nutrients __________.

in sufficient quantity and quality

Why is hypervitaminosis involving water-soluble vitamins relatively UNCOMMON?

Excessive amounts are readily excreted in the urine.

The factors that make protein catabolism an IMPRACTICAL source of quick energy include which of the following?

Proteins are more difficult to break apart. One of the by-products, ammonia, is a toxin that can damage cells. Proteins are important structural and functional cellular components.

Why is it that fatty acids and many amino acids CANNOT be converted to glucose?

Their catabolic pathways produce acetyl-CoA.

Metabolism refers to __________.

all the chemical reactions in the body

Which of the following hormones exhibits its influence most during the postabsorptive state?

glucagon

The basal metabolic rate (BMR) is __________.

the minimum resting energy of an awake, alert person, measured by monitoring respiratory activity, 70 cal/hr or 1680 cal/day in the average individual

No kidding: The town of Nederland, Colorado, has a winter festival called Frozen Dead Guy Days. A man named Bredo Morstoel, a native Norwegian, was born in 1900 and died in 1989. After his death, his grandson had his body cryogenically frozen and stored it in a shed in Colorado until a future date when he supposedly will be resuscitated. Why will this thawing procedure NOT bring Mr. Morstoel back to life?

Freezing temperatures cause water to expand, which would burst cell membranes. The ratio of surface area to volume is low in Mr. Morstoel's body, meaning that ice crystals would have formed during the freezing process. Death had already occurred before the freezing process.

Excess cholesterol leaves somatic cells and is absorbed by __________, which then transport the cholesterol back to the liver.

HDLs

Why can lipogenesis use almost any organic substrate?

Lipids, amino acids, and carbohydrates can be converted to acetyl-CoA.

Why is it that lipids CANNOT provide large amounts of adenosine triphosphate (ATP) in a short period of time?

Most lipids are processed in mitochondria, and mitochondrial activity is limited by the availability of oxygen. Lipids are insoluble, and it is difficult for water-soluble enzymes to reach them. Lipid reserves are difficult to mobilize.

Which of the following individuals does NOT need to modify his or her daily activities to help regulate cholesterol levels?

a 40-year-old woman who weighs 135 pounds, has a total cholesterol level of 150 mg/dL, and does not have a history of atherosclerosis

Phoebe grew up in Alaska's interior and used to play with her friends at recess in temperatures of −20°F. In fact, her school was not canceled until the temperatures reached −50°F. Which of the following terms describes her adaptation to Alaska's frigid winter climate?

acclimatization

To examine the metabolic state of an individual, results may be expressed as __________.

calories per hour, calories per day, and calories per unit of body weight per day

The process that breaks down organic substrates, releasing energy that can be used to synthesize ATP or other high-energy compounds, is __________.

catabolism

When blood glucose concentrations are elevated, the glucose molecules are __________.

catabolized for energy

A diet deficient in essential fatty acids would _____.

slow growth, alter the appearance of the skin, and cause a decrease in the production of prostaglandins

If excess glucose still remains in the circulation after glycogen formation, the hepatocytes use glucose to __________.

synthesize triglycerides

Although small quantities of lipids are normally stored in the liver, most of the synthesized triglycerides are bound to __________.

transport proteins

What is the primary function of very low-density lipoproteins (VLDLs)?

transporting the triglycerides to peripheral tissues