CH 25
Linoleic acid and linolenic acid are examples of
essential fatty acids
The nutrients that yield the most energy per gram when metabolized are
fats
The vitamin that is a coenzyme in amino acid and nucleic acid metabolism is
folic acid (folate)
An element that is a component of hemoglobin, myoglobin, and cytochromes is
iron
Catabolism of protein is not a practical source of quick energy because of all of the following, EXCEPT that
most individuals have little protein to spare before harming vital organs
During starvation
muscle proteins are used as an energy source
The vitamin that is part of the coenzyme NAD is
niacin
A T4 assay is used to
obtain an index of metabolic activity.
The ______ of the mitochondrion contains large-diameter pores that are permeable to ions and small organic molecules such as pyruvic acid.
outer membrane
Nitrogen compounds of the body include all of the following, EXCEPT
oxaloacctic acid
The citric acid cycle is an aerobic process because
oxygen is needed to remove from carbon atoms as carbon dioxide
The vitamin that is a constituent of coenzyme A is
pantothenic acid
An ion that is a necessary component of high-energy compounds and nucleic acids and a structural component of bone is the ____ ion
phosphate
Factors that influence an individuals BMR (basal metabolic rate) include all of the following, EXCEPT
physical exertion
When the body is relying on internal energy reserves to continue meeting its energy demands, it is in the
postabsorptive state
The major cation in cytoplasm is
potassium
Lipids
provide energy for cells with modest energy demands
A vitamin obtained from meat that is a coenzyme in amino acid and lipid metabolism is
pyridoxine (B6)
(Figure 25-1 The Citric Acid Cycle) What is the molecule labeled "1"?
pyruvate acid
More than half the heat is lost from the body indoors through the process of
radiation
The loss of infrared energy from the body is called
radiation
During the absorptive state,
the liver forms glycogen
In oxidative phosphorylation, energy for the synthesis of ATP is directly obtained from
the movement of hydrogen ions through channels in the inner mitochondrial membrane
In glycolysis, each molecule of glucose that is catabolized gives a net yield of how many molecules of ATP?
2
Hydrogen atoms from on FADH2 from the citric acid cycle produce how much ATP in the Electron Transport System?
2 ATP
The chemical equation that correctly summarizes the overall reaction in oxidative phosphorylation is
2 H2 + O2 ---->2 H2O
On a tour of African countries, Mark contracts a bad case of traveler's diarrhea. Because he can't eat very much, his body starts to use energy sources other than carbohydrates. This would result in
All of the answers are correct.
Which of the following statements regarding brown fat is FASLE?
Brown fat is concentration around visceral organs in the adult
Most of the ATP from metabolism is produced in the
Electron Transport System
Compounds that cells can use to make glucose include all of the following, EXCEPT
acetyl-CoA
In order for glycolysis to proceed, which of the following need NOT be present?
acetyl-CoA
Lipogenesis generally beings with
acetyl-CoA
Metabolism of amino acids in the citric acid cycle yields
approximately the same energy as carbohydrate metabolism
The citric acid cycle
begins with the formation of a molecule of citric acid
Oxygen is an important molecule in which of the following?
citric acid cycle and ETS
The trace element needed for hemoglobin synthesis is
copper
Each cytochrome contains
a metal ion
Obesity is defined as a body weight more than ____ percent above the ideal body weight for an individual.
20
If 8 molecules of NADH from the citric acid cycle entered the ETS, how much ATP would be produced?
24 ATP
How many net ATP molecules are produced by the complete metabolism (all pathways) of one glucose molecule?
36 ATP
(Figure 25-1 The Citric Acid Cycle) What is the molecule labeled "7"?
4 carbon molecule
What percent of energy released from catabolism is lost as heat?
60
For adults there are ______ essential amino acids
8
The vitamin that plays a role in maintaining epithelia and is required for the synthesis of visual pigments is vitamin
A
In the ETS, ______ accepts electrons from one molecule and transfers them to another.
A coenzyme
The end products of glycolysis are
ATP, NADH, and pyruvic acid
A balanced diet should
All of the answers are correct
Cells must synthesize new organic compounds
All of the answers are correct
Cells perform catabolism to generate ATP, which can be used for
All of the answers are correct
Cells synthesize new organic components for which of the following reasons?
All of the answers are correct
During glycolysis
All of the answers are correct
Glucocorticoids have which of the following effects on general peripheral tissues?
All of the answers are correct
In the electron transport chain
All of the answers are correct
In the human body, cholesterol is important because it
All of the answers are correct
Someone with a total cholesterol level between 200 and 239mg/dl should
All of the answers are correct
The food pyramid recommends many servings a day of dark-green and orange vegetables. Which vitamin is particularly abundant in this food group?
All of the answers are correct
The heat-gain center for thermoregulation
All of the answers are correct
Wally decides to go on a hunger strike to further one of his favorite causes. After many days with nothing but water you would expect to observe
All of the answers are correct
Removal of the amino group from amino acids in the first step of their catabolism requires a coenzyme derived from vitamin
B6
(Figure 25-1 The Citric Acid Cycle) What is the molecule labeled "2"?
Carbon dioxide
Inadequate exposure to sunlight could result in decreased amounts of vitamin ____ in the body.
D
The vitamin that is required for proper bone growth and for calcium absorption and retention is vitamin
D
The vitamin that prevents breakdown of vitamin A and fatty acids is vitamin
E
The vitamin that is essential for the production of several clotting factors is vitamin
K
Which of the following individuals would lose heat the FASTEST in a cold room?
a newborn infant
Assuming they all weigh the same and maintain the same body temperature, which of the following would lose heat the FASTEST?
a tall, very slender person
Reactions within _____ provide most of the energy needed by a typical cell.
The mitochondria
The conversion of ammonia into a less toxic substance produces
Urea
All of the following occur when the TEMPERATURE of the preoptic area of the hypothalamus drops below its thermostat setting, EXCEPT that
blood flow to the skin increases
A cation that is essential for muscle contraction, nerve function, and blood clotting is
calcium
The strategy of eating starchy foods for several days before an athletic event is known as
carbohydrate loading
The end products or a 0f aerobic respiration are
carbon dioxide, water, and energy (ATP)
The major anion in body fluids is
chloride
The largest lipoproteins, ranging in diameter up to .5mm, ______ are produced by intestinal epithelial cells from the fats in food.
chylomicrons
The lipoproteins that carry absorbed lipids from the intestinal tract to the bloodstream are
chylomicrons
(Figure 25-1 The Citric Acid Cycle) What is the molecule labeled "5"?
citric acid
In the citric acid cycle, a 2 carbon molecule and a 4 carbon molecule combine to produce
citric acid
Although other nutrients can feed into the citric acid cycle, _____ yields energy the quickest.
glucose
A high uric acid level (above 7.4 mg/dl) can lead to the a painful condition known as
gout
Which of the following complements the actions of glucocorticoids?
growth hormone
The condition when excessive fluid loss from sweating disrupts thermoregulatory mechanisms is known as
heat exhaustion
Sometimes called "good cholesterol", ______ carry excess cholesterol from peripheral tissues to the liver
high-density lipoproteins (HDLs)
(Figure 25-1 The Citric Acid Cycle) What is the substance labeled "4"?
hydrogen atoms
The presence of ketone bodies in the urine is known as
ketonuria
All of the following occur during the postabsorptive state, EXCEPT that
levels of blood glucose are elevated
The essential fatty acids are
linoleic acid and linolenic acid
All of the following are true of beta-oxidation, EXCEPT that
lipids are converted into glycogen molecules
Urea is formed in the
liver
A cation that often acts as a cofactor for enzymes is
magnesium
The sum of all the biochemical processes going on within the human body at any given time is called
metabolism
The citric acid cycle occurs in the
mitochondrial matrix
When NAD+ is _______ it becomes NADH. When NADH is ______ it becomes NADH+.
reduced; oxidized
The function of the citric acid cycle is to
remove hydrogen atoms from organic molecules and transfer them to coenzymes
The vitamin that is part of the coenzymes FAD and FMN is
riboflavin
When the temperature of the preoptic area of the hypothalamus exceeds its thermostat setting,
skin blood flow increases and tidal volume increases
The major cation in extracellular fluid is
sodium
The main purpose of the citric acid cycle is to
supply hydrogen atoms to the mitochondria
The major steps in oxidative phosphorylation include all of the following, EXCEPT
the breaking of carbon-carbon covalent bonds
The carbon dioxide of respiration is formed during
the citric acid cycle
The vitamin whose deficiency causes "beriberi" is
thiamine
In oder to determine the LDL level in a patient's blood it is necessary to measure
total cholesterol level, HDL level, and triglyceride level
In "transamination", the amino group of an amino acid is
transferred to a keto acid
What is the role of NADH in metabolism?
transport hydrogen atoms to coenzymes in the mitochondrial cristae
During lypolysis
triglycerides are broken down into glycerol and fatty acids
Impaired fat absorption in the intestine would interfere with the absorption of
vitamin A
The element that is necessary for the proper function of the enzyme carbonic anhydrase is
zinc
