Chapter 25 Flashcards
Chemical reactions that break down complex organic molecules into simpler ones are called:
a) Metabolism
b) Anabolism
c) Catabolism
d) Metatheses
e) Oxidation reactions
c) Catabolism
Chemical reactions that combine simple molecules and monomers to form complex structures are known as
a) Metabolism
b) Anabolism
c) Catabolism
d) Metatheses
e) None of these choices
b) Anabolism
When the terminal phosphate is cut off of ATP what is formed?
a) Adenosine diphosphate
b) GTP
c) Adenosine monophosphate
d) Metabolic water
e) Glucose
a) Adenosine diphosphate
Oxidation is
a) The removal of protons
b) The removal of electrons
c) The addition of protons
d) The addition of electrons
e) None of these choices
b) The removal of electrons
Reduction is the
a) The removal of protons
b) The removal of electrons
c) The addition of protons
d) The addition of electrons
e) None of these choices
d) The addition of electrons
Which of the following is a derivative of riboflavin?
a) NAD
b) FAD
c) Lactic acid
d) Pyruvic acid
e) ADP
b) FAD
Which of the following is NOT a form of phosphorylation?
a) Reduction phosphorylation
b) Substrate level phosphorylation
c) Oxidative phosphorylation
d) Photophosphorylation
e) None of these choices
a) Reduction phosphorylation
Glycogenesis is NOT
a) performed by the hepatocytes
b) performed by muscle fibers
c) one way to make glycogen
d) one way to make glucose
e) only seen in the liver
d) one way to make glucose
Which process describes the synthesis of triglycerides?
a) Gluconeogensis
b) Lipogenesis
c) Phosphorylation
d) Glycolysis
e) Lipolysis
b) Lipogenesis
Which reaction describes the oxidization of acetyl CoA to produce carbon dioxide, ATP, NADH + H+ and FADH2?
a) Glycolysis
b) Formation of acetyl co-A
c) Krebs cycle
d) Electron transport chain
e) Phosphorylation
c) Krebs cycle
Glycolysis, formation of acetyl CoA, Krebs cycle and the electron transport chain are all involved in:
a) Lipogensis
b) Gluconeogenesis
c) Glucose catabolism
d) Formation of Glycogen
e) Formation of vitamin C
c) Glucose catabolism
Which of the following is the key regulator of the rate of glycolysis?
a) ATP
b) NADH
c) Phosphofructokinase
d) Glyceraldehyde-3-phosphate
e) FAD
c) Phosphofructokinase
Where can pyruvate dehydrogenase be found?
a) Cytosol of the cell
b) Plasma membrane
c) Lysozyme
d) Mitochondria
e) Interstitial fluid
d) Mitochondria
The most abundant product of the reactions of the Krebs cycle is
a) Carbon dioxide
b) GTP
c) Reduced coenzymes
d) pyruvate
e) water
c) Reduced coenzymes
The net result of the complete oxidation of glucose does NOT include:
a) water
b) carbon dioxide
c) ATP
d) oxygen
e) waste heat
d) oxygen
How many reactions take place during the Krebs cycle?
a) 4
b) 6
c) 8
d) 10
e) 12
c) 8
Accumulation of a large amount of H+ between the inner and outer mitochondrial membranes, is described as
a) Proton pump
b) Chemiosmosis
c) Krebs cycle
d) ATP synthesis
e) Glycolysis
b) Chemiosmosis
How many ATPs can come from substrate level phosphorylation during glycolysis?
a) 0
b) 1
c) 2
d) 3
e) 4
c) 2
What hormone stimulates glycogenesis?
a) Insulin
b) Glucase
c) Estrogen
d) Lactic acid
e) Protease
a) Insulin
What hormone stimulates gluconeogenesis?
a) Insulin
b) Human Growth hormone
c) Epinephrine
d) Thyroid hormone
e) Cortisol
e) Cortisol
Glycogenolysis is _____ and stimulated by _____.
a) Anabolic, Insulin
b) Catabolic, Epinephrine
c) Catabolic, Insulin
d) Anabolic, Epinephrine
e) Metathesis, Insulin
b) Catabolic, Epinephrine
Thyroid hormones:
a) Aid in glycogenesis
b) Inhibit gluconeogensis
c) Inhibit lipogenesis
d) Promote glycolysis
e) Promote gluconeogenesis
d) Promote glycolysis
Which of the following transport dietary lipids?
a) Apoproteins
b) Low density lipoproteins
c) Chylomicrons
d) Very low density lipoproteins
e) High density lipoproteins
c) Chylomicrons
Most cholesterol medications are designed to:
a) Inhibit excretion of bile in the feces
b) Promote the absorption of cholesterol
c) Decrease the filtration of cholesterol
d) Inhibit glucose absorption
e) None of these choices
e) None of these choices
Where does glycolysis take place?
a) Cytosol
b) Plasma membrane
c) Nucleus
d) Mitochondria
e) Golgi Apparatus
a) Cytosol
Where does the Krebs cycle take place?
a) Cytosol
b) Plasma membrane
c) Nucleus
d) Mitochondria
e) Golgi Apparatus
d) Mitochondria
Lipogenesis occurs when
a) More calories are consumed than required for ATP need
b) Less calories are consumed than required for ATP need
c) More cholesterol is consumed than required for ATP need
d) Less cholesterol is consumed than required for ATP need
e) Gluconeogenesis fails
a) More calories are consumed than required for ATP need
Excess amino acids in the body are
a) Excreted in urine
b) Excreted in feces
c) Converted into glucose
d) Stored as ATP
e) Converted into proteins
c) Converted into glucose
Liver cells convert:
a) Urea into ammonia
b) Ammonia into lactic acid
c) Lactic acid into urea
d) Pyruvic acid into urea
e) Ammonia into urea
e) Ammonia into urea
Glucose-6-phosphate
a) Can be used to make ribose-5-phosphate
b) Can be dephosphorylated to glucose
c) Can be used to synthesize glycogen
d) Can be converted to pyruvic acid
e) All of these choices
e) All of these choices
Which of the following are used in “metabolic crossroads”?
a) Pyruvic acid
b) Glycogen
c) Ribose
d) ATP
e) Lipase
a) Pyruvic acid
In the absorptive state
a) Storage of energy is important
b) Filtration is important
c) Reabsorption is important
d) Synthesis is important
e) Production of heat is important
a) Storage of energy is important
In the absorptive state, most glucose that enters the liver is converted to
a) Pyruvic acid
b) Glycogen
c) Amino acids
d) Insulin
e) Glucase
b) Glycogen
Keto acids
a) Can enter the Krebs cycle
b) Are used for ATP production
c) Can be used to make lipids
d) Can enter Krebs or be used for ATP production
e) Convert into aldehydes in the liver
d) Can enter Krebs or be used for ATP production
Which of the following is NOT a postabsorptive state reaction?
a) Breakdown of liver glycogen
b) Lipogenesis
c) Gluconeogenesis using lactic acid
d) Gluconeogenesis using amino acids
e) None of these choices
b) Lipogenesis
Cardiac muscles can produce ATP from
a) Lactic acid
b) Pyruvic acid
c) Glucose-6-phosphate
d) Proteins
e) Lipids
a) Lactic acid
The most dramatic metabolic change that occurs with fasting is
a) Decrease in the formation of ketone bodies
b) Increase in ATP production
c) Inhibition of insulin
d) Decrease in heart rate and blood pressure
e) Increase in lipolysis
e) Increase in lipolysis
Why is Calorie always spelled with a capital “C”?
a) It is named after Dr. Calorie
b) It is named for the country where it was discovered
c) It is named after the province where it was discovered
d) To distinguish it from the chemistry term calory
e) None of these choices
e) None of these choices
Which of the following is a factor that does NOT affect heat production?
a) Exercise
b) Hormones
c) Nervous system
d) Ingestion of food
e) Blood volume
e) Blood volume
Which of the following is a mechanism of heat transfer that involves direct contact?
a) Conduction
b) Convection
c) Radiation
d) Evaporation
e) Metabolic rate
a) Conduction
The higher the relative humidity
a) The higher the rate of radiation
b) The lower the rate of conduction
c) The higher the rate of convection
d) The lower the rate of thermoregulation
e) The lower the rate of evaporation
e) The lower the rate of evaporation
The heat promoting center stimulates parts of the brain that
a) Decrease smooth muscle tone
b) Increase blood glucose
c) Stimulates skeletal muscle activity
d) Inhibits the sympathetic division
e) None of these choices
c) Stimulates skeletal muscle activity
Thyrotropin-releasing hormone is secreted by the
a) Anterior pituitary
b) Hypothalamus
c) Cerebral cortex
d) Liver
e) Kidney
b) Hypothalamus
Food induced thermogenesis
a) Accounts for 30% of total energy expended
b) Is known as insensible loss
c) Is inhibited by the hypothalamus
d) Is the opposite of ketosis
e) None of these choices
e) None of these choices
Neuropeptide Y stimulates
a) Release of insulin
b) Inhibition of glucagons
c) Thirst centers
d) Thermogenesis
e) Food intake
e) Food intake
Which of the following is not a major nutrient the body needs?
a) Carbohydrates
b) Glycogen
c) Proteins
d) Minerals
e) Vitamins
b) Glycogen
Provitamins are
a) Building blocks of vitamins
b) Broken down glucose molecules
c) Derivatives of minerals
d) Found only in the blood
e) Not stored in the body
a) Building blocks of vitamins
Which of the following is a fat-soluble vitamin?
a) Vitamin B
b) Vitamin E
c) Vitamin C
d) Vitamin O
e) None of these choices
b) Vitamin E
Antioxidant vitamins
a) Are found in plasma membranes
b) Are vitamin derivatives
c) Can inactivate oxygen free radicals
d) Are all excreted in feces
e) Are all stored in adipose cells
c) Can inactivate oxygen free radicals
Briefly outline the possible fates of glucose in the body.
1) immediate oxidation for ATP production
2) synthesis of amino acids for protein synthesis
3) synthesis of glycogen for storage in liver and skeletal muscle
4) formation of triglycerides via lipogenesis for long term storage after glycogen stores are full
5) excretion in urine if blood glucose is very high
What are the possible fates of pyruvic acid in the body? What is the primary determinant of the fate of pyruvic acid? What is the fate of compounds to which pyruvic acid may be converted?
Pyruvic acid in the presence of low oxygen is reduced to lactic acid, which is converted to either glycogen or carbon dioxide. In the presence of high oxygen levels, pyruvic acid is converted to an acetyl unit, which may be carried into the Krebs cycle by coenzyme A or converted into fatty acids, ketone bodies, or cholesterol.
Identify the different types of lipoproteins and describe the function of each.
Chylomicrons transport dietary lipids in the lymph and blood. Very low density lipoproteins transport endogenous triglycerides from hepatocytes to adipocytes for storage. Low density lipoproteins transport cholesterol through the body for use in repair of membranes and synthesis of steroid hormones and bile salts. High density lipoproteins transport excess cholesterol to the liver for elimination.
Describe the role of the hypothalamus in regulation of food intake.
The hypothalamus contains the neurons of the feeding center that stimulate eating and of the satiety center that signal fullness. Two nuclei in the hypothalamus that help regulate food intake are the arcuate and paraventricular nuclei. The hormone leptin, released by adipocytes, inhibits release of neuropeptide Y from the arcuate nucleus and thereby decreases food intake. Melanocortin also decreases food intake. It is thought that changes in blood chemistry (in terms of nutrients and hormone balance), as well as distention of the gastrointestinal tract, initiate appropriate hypothalamic activity.
Which vitamins are considered “antioxidant vitamins?” Why is this role so important?
Vitamins C, E, and beta carotene (a provitamin) are antioxidants that inactivate oxygen free radicals. Free radicals damage cell membranes, DNA, and other cell structures. They also contribute to the formation of atherosclerotic plaque. Antioxidant vitamins may also decrease cancer risk, delay aging, and decrease the risk of cataract formation.
Why are 10 of the amino acids in the human body designated as essential amino acids?
Essential amino acids are amino acids that must be present in the diet because they cannot be synthesized in the body in adequate amounts. They include isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan, and valine. The amino acids arginine and histidine can be synthesized only in inadequate amounts. Thus, these amino acids must be supplied in the diet.
What is the difference between a complete protein and an incomplete protein?
Complete proteins contain sufficient amounts of all essential amino acids. Incomplete proteins do not contain all essential amino acids.
Which of the following is NOT a fate that awaits glucose 6-phophate after it is formed in a cell?
a) Synthesis of glycogen
b) Release of glucose into the blood stream
c) Synthesis of nucleic acids
d) Glycolysis
e) Gluconeogenesis
e) Gluconeogenesis
Which hormone(s) dominate(s) the absorptive state?
a) Insulin
b) Glucagon
c) HGH
d) All of these
e) None of these
a) Insulin
Which hormone is the primary hormone involved in protein breakdown in the postabsorptive state?
a) Glucagon
b) Epinephrine
c) Cortisol
d) Glucagon
e) Thyroid Hormone
c) Cortisol
Which of the following helps the core temperature to increase?
a) Constriction of blood vessels of the skin.
b) Increase in cellular respiration.
c) Shivering.
d) Thyroid hormone induced increase in metabolic rate.
e) All of these are methods for core temperature increase.
e) All of these are methods for core temperature increase.
Which of the following is NOT a factor that affects the metabolic rate and the rate of heat production?
a) Hormones
b) Nervous system
c) Food ingestion
d) Age
e) All of these are factors
e) All of these are factors
Where is the body’s thermostat located?
a) Cerebral cortex
b) Preoptic area of the hypothalamus
c) Postoptic area of the hypothalamus
d) Thalamus
e) Cerebellum
b) Preoptic area of the hypothalamus
Which mineral is the most abundant mineral in the body?
a) Calcium
b) Sodium
c) Magnesium
d) Phosphorus
e) Iron
a) Calcium
Which nutrient is required by the thyroid gland to synthesize thyroid hormones?
a) Calcium
b) Magnesium
c) Iodide
d) Manganese
e) Sodium
c) Iodide
Which of the following is NOT a function of phosphorus in the body?
a) Formation of bones and teeth
b) Constitute a major buffer system of blood
c) Component of DNA and RNA
d) Component of many enzymes
e) Affects distribution of water through osmosis
e) Affects distribution of water through osmosis
Which of the following is needed for the synthesis of thyroid hormones?
a) Zinc
b) Chromium
c) Selenium
d) Cobalt
e) Copper
c) Selenium
Which vitamin is essential for the absorption of calcium and phosphorus from the GI tract?
a) A
b) D
c) E
d) K
e) C
d) K
Which vitamin deficiency can result in rickets in children and osteomalacia in adults?
a) A
b) B
c) C
d) D
e) E
d) D
Which vitamin deficiency can result in hemolytic anemia?
a) A
b) B
c) C
d) D
e) E
e) E
Which of the following disorders is a disorder in which protein intake is deficient despite normal or nearly normal caloric intake?
a) Marasmus
b) Kwashiorkor
c) Bulimia
d) Malnutrition
e) None of these
b) Kwashiorkor
Which of the following describes a severe and often fatal disorder caused by exposure to high temperatures?
a) Heat cramps
b) Heat exhaustion
c) Heat prostration
d) Heatstroke
e) None of these
d) Heatstroke
Which of the following is a protein-calorie under-nutrition that results in retarded growth, low weight, muscle wasting, emaciation, and dry skin?
a) Marasmus
b) Kwashiorkor
c) Malnutrition
d) Both Marasmus and Kwashiorkor
e) Both Kwashiorkor and Malnutrition
a) Marasmus
Which of the following is a potential cause of hypothermia?
a) Overwhelming cold stress
b) Metabolic diseases
c) Drugs
d) All of these
e) None of these
d) All of these
Which hormones are the main stimulating hormones in the postabsorptive state process of glycogenolysis?
a) Epinephrine
b) Glucagon
c) Cortisol
d) Epinephrine and Glucagon
e) Glucagon and Cortisol
d) Epinephrine and Glucagon
Which of the following is not a molecule at the “metabolic crossroads”?
a) Glucose 6-phosphate
b) Pyruvic acid
c) Acetyl coenzyme a
d) Glycogen
e) All of these are molecules at the “metabolic crossroads”
d) Glycogen
