A&P Ch. 25 Metabolism, Nutrition, and Energetics

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

42 percent

Oxidative phosphorylation produces __________ percent of the ATP in our cells.

90

Which of the following statements describes a factor that contributes to thermoregulatory problems in infants?

At birth, temperature-regulating mechanisms are not fully functional. Infant body temperature is more unstable than that of adults. Infants cannot shiver.

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

HDLs

Which of the following has been implicated in plaque buildup and cardiovascular disease?

LDL

Most pathways of lipogenesis begin with __________.

acetyl coenzyme A

Metabolism refers to __________.

all the chemical reactions in the body

Milk and eggs are complete proteins because they contain __________.

all the essential amino acids in sufficient quantities

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

free fatty acids

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

glucagon

Question 34:During open-heart surgery, which of the following thermoregulatory changes will be induced on the patient's body?

hypothermia

Which type of lipid is linked to cholesterol deposition in arterial walls and may require a change in diet to control?

low-density lipoproteins (LDLs)

The TCA, or Krebs, cycle takes place in the __________.

mitochondria

The actual process of ATP formation associated with the electron transport system is called __________.

chemiosmosis

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

citric acid

The direct transfer of energy through physical contact is called __________.

conduction

Glycolysis occurs in the __________.

cytoplasm

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

oxidation

The final acceptor of electrons passing through the electron transport chain is __________, which in turn binds with hydrogen ions to produce __________.

oxygen, water

Because infants cannot control their thermoregulatory rates, they __________.

possess a specialized type of adipose called brown fat also cannot shiver must be dried and promptly bundled to keep them warm

Nitrogen-containing compounds found in the body?

purines pyrimidines amino acids

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

pyruvic acid

A person who consumes very low amounts of vitamin C over a long period of time is at risk for developing __________.

scurvy

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

synthesize triglycerides

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

transporting the triglycerides to peripheral tissues

Nicotinamide adenine dinucleotide (NAD) and flavin adenine dinucleotide (FAD) pick up the majority of hydrogen ions and electrons from which step in the aerobic cellular respiration?

tricarboxylic acid (TCA) cycle

Amino acids are deaminated and the amine group is ultimately excreted as __________.

urea

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

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

leucine, lysine, valine, tryptophan, arginine

Essential fatty acids

linoleic acid linolenic acid

Lipids circulate through the bloodstream as __________.

lipoproteins and free fatty acids

The breakdown of fatty acid molecules yields __________ the breakdown of similar carbohydrates.

more ATP than

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

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

Glycolysis occurs __________.

whether or not oxygen is present

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

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

1. Proteins are important structural and functional cellular components. 2. Proteins are more difficult to break apart. 3. One of the by-products, ammonia, is a toxin that can damage cells.

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?

1. 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. 2. Freezing temperatures cause water to expand, which would burst cell membranes. 3. Death had already occurred before the freezing process.

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

1. calories per hour 2. calories per day 3. calories per unit of body weight per day

Carbohydrate depletion followed by carbohydrate loading __________.

1. can be harmful to the muscles and kidneys 2. is a practice athletes sometimes use to obtain the maximum levels of ATP from carbohydrates before an athletic event 3. involves exercising to exhaustion up to three days before an athletic event

What foods are high in dietary fiber?

1. rice and pastas 2. vegetables and fruits 3. breads and cereals

A diet deficient in essential fatty acids would __________.

1. slow growth 2. alter the appearance of the skin 3. cause a decrease in the production of prostaglandins

The basal metabolic rate (BMR) is __________.

1. the minimum resting energy of an awake, alert person 2. measured by monitoring respiratory activity 3. 70 cal/hr or 1680 cal/day in the average individual

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

144 ATP

Glycolysis produces a net gain of __________ ATP molecules from each glucose molecule.

2

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 products of glycolysis include which of the following?

ATP NADH pyruvic acid

How does neural tissue normally respond during the postabsorptive state?

In the postabsorptive state, the activities of neural tissue do not change in comparison to its activities in the absorptive state.

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

The body cannot synthesize the nutrients in sufficient quantities.

High-density lipoproteins __________.

are sometimes called "good cholesterol"

Which of the following carries lipids from the digestive tract to the circulatory system?

chylomicrons

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

creatine

The synthesis of glucose from noncarbohydrates is called __________.

gluconeogenesis

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

gluconeogenesis

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

in sufficient quantity and quality

What is the effect of androgens and estrogens on general peripheral tissues?

increased amino acid use in protein synthesis

Statements concerning free fatty acids.

1. Free fatty acids can diffuse out of lipid stores when triglycerides are broken down. 2. Free fatty acids in the blood are usually bound to albumin. 3. Free fatty acids can be metabolized by many body cells.

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

1. Lipid reserves are difficult to mobilize. 2. Most lipids are processed in mitochondria, and mitochondrial activity is limited by the availability of oxygen. 3. Lipids are insoluble, and it is difficult for water-soluble enzymes to reach them.

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

1. growing children 2. a pregnant woman 3. athletes in training

Why is hypervitaminosis involving water-soluble vitamins relatively UNCOMMON?

Excessive amounts are readily excreted in the urine.

Why can lipogenesis use almost any organic substrate?

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

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

Their catabolic pathways produce acetyl-CoA.

The breakdown of fatty acid molecules into two carbon fragments is called __________.

beta-oxidation

Essential amino acids __________.

cannot be synthesized in the human body and cannot be synthesized in sufficient amounts for children

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

catabolism

Which of the following is NOT a mechanism for heat loss?

inhibition of the vasomotor center causing peripheral vasodilation and the flow of warm blood to the surface of the body increasing activity in the sympathetic vasomotor center stimulation of the respiratory centers, leading to deeper respiration stimulation of sweat glands and their secretory output

Which of the following hormones does NOT have important functions during the postabsorptive state?

insulin

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

Amino groups can be removed from amino acids by __________.

both deamination and transamination

The enzyme lipoprotein lipase __________.

digests lipid complexes into free fatty acids and monoglycerides

Statements about hypervitaminosis.

Hypervitaminosis involving vitamin D can cause fatigue, weight loss, and potentially severe damage to the kidneys and cardiovascular system. Hypervitaminosis involving vitamin A can cause nausea, dizziness, lethargy, and even death.

Which of the following statements is TRUE concerning basal metabolic rate (BMR) and thermoregulation?

Individuals who lose body heat rapidly have higher BMRs than those who do not. A simple way to determine an individual's BMR is to monitor respiratory activity. Assuming average catabolism of carbohydrates, proteins, and lipids, for each liter of oxygen a person consumes, 4.825 calories are generated.

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, you will also spend 12 hours in postabsorptive state.

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

The breakdown of fatty acid molecules results in the production of __________.

acetyl coenzyme A

The transition between glycolysis and the TCA cycle involves a molecule called __________.

acetyl coenzyme A

Catabolism __________.

both produces ATP and heat and breaks down organic molecules

Some amino acids can be used to make ATP because they can be converted to __________.

both pyruvic acid and acetyl CoA

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

catabolism of fatty acids

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

catabolized for energy

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

transport proteins