Unit 8 Metabolism practice quiz
________ contains all of the essential amino acids.
A complete protein
The molecule that supplies our cells with an immediate source of energy is:
ATP
Which of the following is calculated directly by using a person's height and weight?
BMI
Deficiency in what vitamin can result in a condition called scurvy?
C
Lipogenesis generally begins with
Acetyl CoA
True or False: One of the major results of cellular respiration is heat.
True
True or False: When ATP breaks down, the products can then be used to synthesize more ATP.
True
Carbohydrates and proteins may be converted to triglycerides and stored as fat.
True. Any calorie containing nutrient can be stored as fat in the body.
Where in the cell does electron transport occur?
cristae of mitochondria
Poisons like cyanide bind to ________ and prevent electron transfer.
cytochromes
site of oxidation/reduction reactions in electron transport
cytochromes
Where in a cell does glycolysis occur?
cytoplasm
28 ATP produced
electron transport
During cellular respiration, which set of reactions produces water?
electron transport
Most of the ATP in our cells is produced during:
electron transport
Which of these is a hormone that causes an increase in blood glucose concentration?
epinephrine
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
It's been 5 hours since you had breakfast and now you're thinking about trying the new Mexican lunch place that just opened up across the street. The more you think about it, the hungrier you get. That's the result of the ________ that your empty stomach is releasing into your bloodstream.
ghrelin
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
end product is pyruvic acid
glycolysis
A high uric acid level (above 7.4 mg/dl) can lead to the painful condition known as
gout
Temperature regulation is:
influenced by peripheral thermoreceptors in the skin
A decrease in body weight occurs when caloric intake:
is less than basal metabolism plus external work
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
Which of the following have the most similar functions?
niacin (NAD) and riboflavin (FAD)
NAD, which acts as a hydrogen carrier in the cell, is derived from:
niacin (nicotinic acid).
Coenzyme A is derived from:
pantothenic acid (vitamin B5)
When the body is relying on internal energy reserves to continue meeting its energy demands, it is in the ________ state.
postabsorptive
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
For each molecule of glucose converted to pyruvic acid:
two molecules of ATP are broken down and four are synthesized.
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)
Which of the following is an end product of the electron transport chain?
water
The metabolic rate of an individual may be lower than the BMR
while sleeping
The process that catabolizes fatty acids to acetyl-CoA is called
beta-oxidation
pathway for fatty acid breakdown
beta-oxidation
In a healthy individual who has just finished eating a large nutrient-balanced meal:
blood plasma will have an increased concentration of fats, glucose, and amino acids
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
A deficiency in vitamin D would result in which of the following disorders?
rickets
Acetyl CoA is important in cellular metabolism because it:
serves as an intermediate in multiple energy pathways, for the metabolism of glucose, fatty acids, and amino acids.
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
Obesity is defined as a body weight more than ________ percent above the ideal body weight for an individual.
20
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.
The vitamin that plays a role in maintaining epithelia and is required for the synthesis of visual pigments is vitamin
A
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
A decrease in body weight occurs when more calories are consumed than is necessary to meet the metabolic requirements of the cells.
False
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
Niacin (vitamin B3) is important for ATP synthesis because it forms NAD. What specific role does NAD play in energy metabolism?
It transfers hydrogens released during glycolysis and Krebs cycle to the electron transport system.
Glycolytic breakdown of glucose first results in ________ molecules.
a) 2 pyruvate (pyruvic acid) b) 2 NADH c) 2 ATP (net) d) 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?
a) A b) C c) E d) folic acid e) All of the answers are correct
Glucocorticoids have which of the following effects on general peripheral tissues?
a) They increase the conversion of amino acids to pyruvate. b) They increase gluconeogenesis. c) They increase glycogenolysis. d) All of the answers are correct.
A balanced diet should
a) include adequate substrates for the production of energy. b) provide essential amino acids and fatty acids. c) contain adequate amounts of vitamins and minerals. d) All of the answers are correct.
ATP can be used for
a) muscle contraction. b) ion transport. c) protein synthesis. d) glycogen synthesis. e) All of the answers are correct
The electron transport system
a) receives electrons from coenzymes. b) produces more the ATP than Glycolysis c) is located on the inner mitochondrial membrane (the cristae). d) All of the answers are correct.
Cells synthesize new organic components for which of the following reasons?
a) structural maintenance b) growth and repair c) production of secretions d) All of the answers are correct.
Amino acids can be converted into:
a.) fatty acids b.) other amino acids. c.) glucose. d.) all of the above
Regulation of body temperature is controlled by:
a.) shivering b.) vasodilation of cutaneous vessels c.) is regulated by a center in the hypothalamus d.) all of the above
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
________ is deficient in one or more of the essential amino acids.
an incomplete protein
The minimum resting energy expenditure of an awake, alert person is called
basal metabolic rate
The citric acid cycle
begins with the formation of a molecule of citric acid.
Which of the following terms describes the process by which glucose is metabolized to produce CO2, H2O, and energy?
catabolism
The largest lipoproteins, ________, 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 the
chylomicrons.
During cellular respiration, which set of reactions releases carbon dioxide?
citric acid (Krebs) cycle
starting material is acetyl-CoA
citric acid cycle
A chemical reaction by which the -NH2 group is removed from an amino acid is known as:
deamination
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
During the absorptive phase of metabolism:
glucose is the primary energy source for most cells
All of the following are reasons why glucose is the primary energy source for cells except
glycogen breakdown occurs very slowly.
Which of the following is most likely to occur if blood glucose levels are elevated?
glycogenesis
In which of the following conditions does the hypothalamus fail to function?
heat stroke
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
A political prisoner has been on a hunger strike for seven days. Compared to normal, he has:
increased release of fatty acids from adipose tissue
All of the following take place during the absorptive state except
ketone bodies begin to form
In skeletal muscle, one major disadvantage of relying solely on glycolysis under anaerobic conditions is that:
lactic acid accumulates in the muscle.
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.
The nutrients that yield the most energy per gram when metabolized are
lipids
During starvation (a long-term situation):
little or no glycogen is stored in the liver
Urea is formed in the
liver
During electron transport, the transfer of electrons through the cytochromes to oxygen:
makes more ATP than can be made directly from glycolysis.
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
Glycolysis breaks down glucose into
pyruvic acid
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
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
Basal metabolism most directly refers to the energy output required:
to maintain basic body functions