Metabolism Quiz
All cells use which of the following directly for energy to fuel their work?
ATP
________ is deficient in one or more of the essential amino acids.
An incomplete protein
The hormone ________, which suppresses appetite and stimulates satiety, is released by adipose tissue.
leptin
All of the following occur during the postabsorptive state except that
levels of blood glucose are elevated.
During electron transport, the transfer of electrons through the cytochromes to oxygen:
makes more ATP than can be made directly from glycolysis.
NAD, which acts as a hydrogen carrier in the cell, is derived from:
niacin (nicotinic acid).
beta-oxidation
pathway for fatty acid breakdown
The increase in body temperature during exercise:
results from a greatly increased metabolism
In transamination, the amino group of an amino acid is ________, yielding a different amino acid.
transferred to another molecule
Low-density lipoproteins function to:
transport cholesterol to cells for use in plasma membranes or hormone synthesis
During lipolysis,
triglycerides are broken down into glycerol and fatty acids.
The citric acid cycle
begins with the formation of a molecule of citric acid.
The process that catabolizes fatty acids to acetyl-CoA is called
beta-oxidation.
When the body is relying on internal energy reserves to continue meeting its energy demands, it is in the ________ state.
postabsorptive
The process by which electrons are transferred from NAD through various cytochromes and finally to oxygen occurs to:
provide energy for ATP formation.
citric acid cycle
starting material is acetyl-CoA
The carbon dioxide of respiration is formed during
the citric acid cycle.
Reactions within ________ provide most of the energy needed by a typical cell.
the mitochondria
Homeostatic control of body temperature is termed
thermoregulation
The vitamin that plays a role in maintaining epithelia and is required for the synthesis of visual pigments is vitamin
A
The food pyramid recommends many servings a day of dark-green and orange vegetables. Which vitamin is particularly abundant in this food group?
A C E folic acid
All of the following are reasons why glucose is the primary energy source for cells except
glycogen breakdown occurs very slowly.
The conversion of one amino acid to another
is done by transamination.
Epinephrine:
is released from the adrenal medulla and acts to stimulate glycogenolysis
Which of the following describes the role of NADH during cellular respiration?
it carries hydrogen to the site of electron transport reactions
All of the following take place during the absorptive state except
ketone bodies begin to form.
The energy content of foods is commonly given in units of
kilocalories (also, kcal or Cal).
In the absence of oxygen, what is produced at the end of glycolysis?
lactic acid
In skeletal muscle, one major disadvantage of relying solely on glycolysis under anaerobic conditions is that:
lactic acid accumulates in the muscle.
The nutrients that yield the most energy per gram when metabolized are
lipids
All of the following are true of beta-oxidation except that
lipids are converted into glycogen molecules.
During starvation (a long-term situation):
little or no glycogen is stored in the liver
Urea is formed in the
liver.
When a cell needs energy, glycogen may be hydrolyzed to
many glucose molecules.
The sum of all of the biochemical processes going on within the human body at any given time is called
metabolism
The function of the citric acid cycle is to
remove hydrogen atoms from organic molecules and transfer them to coenzymes.
Resting energy expenditure is most directly determined by monitoring
respiration
Most nutrient absorption takes place in the
small intestine
Basal metabolism most directly refers to the energy output required:
to maintain basic body functions
Deficiency in what vitamin can result in a condition called scurvy?
C
During cellular respiration, how much of the original energy in the glucose molecule is transferred into ATP and how much is instead converted into (lost as) heat?40% to ATP and 60% to heat.
40% to ATP and 60% to heat.
electron transport
28 ATP produced
________ contains all of the essential amino acids.
A complete protein
The lipoproteins that carry absorbed lipids from the intestinal tract to the bloodstream are the
chylomicrons.
Poisons like cyanide bind to ________ and prevent electron transfer.
cytochromes
Where in a cell does glycolysis occur?
cytoplasm
During cellular respiration, which set of reactions produces the most ATP?
electron transport
glycolysis
end product is pyruvic acid
Regulation of body temperature is controlled by:
shivering vasodilation of cutaneous vessels is regulated by a center in the hypothalamus
cytochromes
site of oxidation/reduction reactions in electron transport
Cells synthesize new organic components for which of the following reasons?
structural maintenance growth and repair production of secretions
Lack of exercise and a caloric intake > basal metabolic rate plus external work for a prolonged period may result in:
type II diabetes
The conversion of ammonia into a less toxic substance produces
urea.
Impaired fat absorption in the intestine would interfere with the absorption of
vitamin A
Pellagra, an epithelial and mucosal deterioration, results from a deficiency in
vitamin B3 (niacin).
A chemical reaction by which the -NH2 group is removed from an amino acid is known as:
deamination.
Which part of glucose metabolism yields the greater amount of ATP?
electron transport system
A person 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
elevated levels of glucocorticoids. ketone bodies in his urine. lowered blood pH.
Which of these is a hormone that causes an increase in blood glucose concentration?
epinephrine
Which of the following increases the breakdown of triglycerides in adipose tissue?
epinephrine thyroid hormone exercise
Fatty acids that are necessary for proper health but cannot be synthesized by the body are called
essential fatty acids.
Linoleic acid and linolenic acid are examples of
essential fatty acids.
The process(es) that occur(s) in the mitochondria is/are:
Krebs cycle. and electron transport
Glucocorticoids have which of the following effects on general peripheral tissues?
They increase the conversion of amino acids to pyruvate. They increase gluconeogenesis. They increase glycogenolysis.
True or False: When ATP breaks down, the products can then be used to synthesize more ATP.
True
Ketone bodies can result from excess production of:
acetyl CoA.
Amino acids and fatty acids may enter the citric acid cycle by way of:
acetyl-CoA
Lipogenesis generally begins with
acetyl-CoA.
The following equation represents: C6H12O6 + 6 O2 --------> 6 CO2 + 6 H2O + ATP + heat
cellular respiration.
Amino acids can be converted into:
fatty acids other amino acids. glucose.
Acetyl CoA for the citric acid cycle may be formed through metabolism of:
fatty acids glucose amino acids
Decreasing blood glucose is a stimulus for the secretion of:
glucagon
Which of the following is most likely to occur if blood glucose levels are elevated?
glucagon and epinephrine
The conversion of glycerol and amino acids into glucose in called:
gluconeogenesis
The process of synthesizing glucose from noncarbohydrates is called
gluconeogenesis.
Although other nutrients can feed into the citric acid cycle, ________ yields energy the quickest.
glucose
There are ________ essential amino acids that the body either cannot synthesize or that cannot be produced in amounts sufficient for growing children.
10
What is the net energy yield of the citric acid (Krebs) cycle?
2 ATP
Inadequate exposure to sunlight can 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
An adult weighing 130 lb. requires the same amount of energy to walk up a flight of stairs as does an adult weighing 280 lb.
False. It requires more energy for the larger adult because he/she has a higher BMI.
Which of the following carry excess cholesterol from peripheral tissues to the liver?
High-density lipoproteins (HDLs)
Which of the following is true about the citric acid, or Krebs, cycle?
It occurs in the matrix of mitochondria
A political prisoner has been on a hunger strike for seven days. Compared to normal, he has:
It transfers hydrogens released during glycolysis and Krebs cycle to the electron transport system.
Which of the following does not release hydrogens that are used to make ATP in electron transport?
all of these release hydrogens for use electron transport
The minimum resting energy expenditure of an awake, alert person is called
basal metabolic rate.
About 60% of the heat loss from a nude person standing in a room at 70 degrees (F) is by radiation. Heat loss in this manner is based on the principal that:
body temperature is greater than the surrounding temperature, so the nude person releases more heat than he receives
Cellular respiration is best described as the:
breakdown of glucose into CO2 and H2O and production of ATP.
Blood glucose levels are increased by:
glycogenolysis
When the blood glucose level becomes low, which of the following would most likely increase?
glycogenolysis
If the cell starts with fat as its fuel source, which of the following reactions will NOT occur?
glycolysis
Which of the following lists the correct sequence of events during carbohydrate metabolism?
glycolysis----Krebs cycle----electron transport
A mature red blood cell has no mitochondria. Because of this, it can only make ATP by:
glycolysis.
A disorder caused by the ingestion of excessive quantities of a fat-soluble vitamin is known as
hypervitaminosis.
At the Holy Frijoles restaurant, you order a burrito grande with extra sour cream and cheese and an order of tortilla chips with guacamole. You're very satisfied with your meal—it's a lot of food—and as you finish off the last of the chips, the satiety center in your ________ starts letting you know that you've had enough to eat now.
hypothalamus
The area of the brain that regulates body temperature is the
hypothalamus
Temperature regulation is:
influenced by peripheral thermoreceptors in the skin
ATP can be used for
muscle contraction. ion transport. protein synthesis. glycogen synthesis.
In the metabolism of proteins, amino acids may be converted to:
nitrogen containing derivatives such as hormones structural proteins new enzymes carbohydrates and fats
The mitochondria are often called the "powerhouses" of the cell because they:
produce most of the ATP (cell energy) generated from glucose.
Glycolysis breaks down glucose into
pyruvic acid
