parkland bio 122 quiz 8- metabolism
The vitamin that plays a role in maintaining epithelia and is required for the synthesis of visual pigments is vitamin
A
Deficiency in what vitamin can result in a condition called scurvy?
C
Which of the following is true about the citric acid, or Krebs, cycle?
It occurs in the matrix of mitochondria
ATP can be used for
a) muscle contraction. b) ion transport. c) protein synthesis. d) glycogen synthesis.
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). *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
Amino acids and fatty acids may enter the citric acid cycle by way of:
acetyl-CoA
Lipogenesis generally begins with
acetyl-CoA.
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.
pathway for fatty acid breakdown
beta-oxidation
The process that catabolizes fatty acids to acetyl-CoA is called
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
In the absence of oxygen, which is the last process that can occur to make ATP?
glycolysis
end product is pyruvic acid
glycolysis
Which of the following lists the correct sequence of events during carbohydrate metabolism?
glycolysis----Krebs cycle----electron transport
A chemical reaction by which the -NH2 group is removed from an amino acid is known as:
deamination.
The caloric requirements of an athlete training for a marathon would most likely be:
greater than the recommended 2000 kcal/day diet for an average adult
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.
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 vitamin that is a coenzyme in amino acid and nucleic acid metabolism is
folic acid (folate).
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
There are ________ essential amino acids that the body either cannot synthesize or that cannot be produced in amounts sufficient for growing children.
10
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.
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
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 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
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
During electron transport, the transfer of electrons through the cytochromes to oxygen:
makes more ATP than can be made directly from glycolysis.
The sum of all of the biochemical processes going on within the human body at any given time is called
metabolism
NAD, which acts as a hydrogen carrier in the cell, is derived from:
niacin (nicotinic acid).
When the body is relying on internal energy reserves to continue meeting its energy demands, it is in the ________ state.
postabsorptive
A person with untreated diabetes mellitus would be in a prolonged:
postabsorptive state
The carbohydrates in an uneaten candy bar can best be described as:
potential energy.
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
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
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.
Most nutrient absorption takes place in the
small intestine
Reactions within ________ provide most of the energy needed by a typical cell.
the mitochondria
Basal metabolism most directly refers to the energy output required:
to maintain basic body functions
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
Poisons like cyanide bind to ________ and prevent electron transfer.
cytochromes
site of oxidation/reduction reactions in electron transport
cytochromes
Where does the breakdown of glucose to pyruvic acid occur?
cytoplasm
Which of the following increases the breakdown of triglycerides in adipose tissue?
-epinephrine -thyroid hormone -exercise *all of the above*
Acetyl CoA for the citric acid cycle may be formed through metabolism of:
-fatty acids -glucose -amino acids *All of the above*
Which of the following does not release hydrogens that are used to make ATP in electron transport?
-glycolysis -conversion of pyruvic acid to acetyl Co-A (pre-citric acid cycle) -citric acid cycle *all of these release hydrogens for use electron transport*
In the metabolism of proteins, amino acids may be converted to:
-nitrogen containing derivatives such as hormones -structural proteins -new enzymes -carbohydrates and fats *all of the above*
The molecule that supplies our cells with an immediate source of energy is:
ATP.
________ is deficient in one or more of the essential amino acids.
An incomplete protein
Which of the following is calculated directly by using a person's height and weight?
BMI
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)
Niacin (vitamin B3) is important for ATP synthesis because it forms NAD. What specific role does NAD play in energy metabolism?
Niacin (vitamin B3) is important for ATP synthesis because it forms NAD. What specific role does NAD play in energy metabolism?
Which of the following statements is true about carbohydrates?
Their main use is to provide energy.
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
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. *All of the answers are correct.*
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
a) elevated levels of glucocorticoids. b) ketone bodies in his urine. c) lowered blood pH. *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. *All of the answers are correct.*
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.
The following equation represents: C6H12O6 + 6 O2 --------> 6 CO2 + 6 H2O + ATP + heat
cellular respiration.
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
Where in the cell does electron transport occur?
cristae of mitochondria
Which of the following hormones increase the blood glucose level?
glucagon and epinephrine
The process of synthesizing glucose from noncarbohydrates is called
gluconeogenesis.
All of the following are reasons why glucose is the primary energy source for cells except
glycogen breakdown occurs very slowly.
Blood glucose levels are increased by:
glycogenolysis
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
The conversion of glycerol and amino acids into glucose in called:
is done by transamination.
A decrease in body weight occurs when caloric intake:
is less than basal metabolism plus external work
Body temperature:
is regulated primarily by regulating heat loss
Which of the following describes the role of NADH during cellular respiration?
it carries hydrogen to the site of electron transport reactions
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
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