Chapter 23 Mastering Questions
In the absorptive state of metabolic activity: A: insulin inhibits glucose uptake and glycogenesis B: androgens, estrogens, and growth hormone stimulate protein synthesis C: epinephrine is important in stimulating glycogenolysis in skeletal and cardiac muscle D: glucocorticoids stimulate the mobilization of lipid and protein reserves
B: androgens, estrogens, and growth hormone stimulate protein synthesis
Fatty acids that are necessary for proper health but cannot be synthesized by the body are called A: essential fatty acids B: water soluble vitamins C: chylomicrons D: high density lipoproteins E: low density lipoproteins
A: essential fatty acids
Which process describes the synthesis of glucose from noncarbohydrate sources? A: gluconeogenesis B: glycolysis C: glycogenesis D: glycogenolysis
A: gluconeogenesis
Which statement regarding the citric acid cycle is true? A: its function is to remove hydrogen atoms from organic molecules and transfer them to coenzymes B: the citric acid cycle occurs in the cytoplasm C: cytochromes are the coenzymes that play a key role in the citric acid cycle D: an acetyl group, CH3CO, from acetyl-CoA is attached to a 6 carbon molecule
A: its function is to remove hydrogen atoms from organic molecules and transfer them to coenzymes
The nutrients that yield the most energy per gram when metabolized are A: lipids B: vitamins C: nucleic acids D: proteins E: carbohydrates
A: lipids
Which characteristic correctly applies to lipid metabolism? A: most lipids can be synthesized on demand B: stored lipids provide large amount of ATP very quickly C: excess lipids can be stored as pyruvate D: triglyceride reserves are water soluble droplets
A: most lipids can be synthesized on demand
The function of the citric acid cycle is to A: remove hydrogen atoms from organic molecules and transfer them to coenzymes B: produce carbon dioxide C: transfer the acetyl group D: hydrolyze glucose E: produce water
A: remove hydrogen atoms from organic molecules and transfer them to coenzymes
Reactions within __________ provide most of the energy needed by a typical cell A: the mitochondria B: cytoplasm C: the endoplasmic reticulum D: the plasma membrane E: none of the answers are correct
A: the mitochondria
Choose the correct statement regarding glycolysis A: there is a net gain of 2 ATP molecules for each glucose molecule B: it is an aerobic process that breaks down a 6 carbon glucose molecule into 2 three carbon molecules of pyruvate C: NAD accepts carbon atoms that can be transferred to mitochondria D: it occurs in the mitochondrion
A: there is a net gain of 2 ATP molecules for each glucose molecule
Which form of glucose metabolism yields the greater amount of ATP? A: citric acid cycle B: electron transport system C: glycolysis + citric acid cycle D: glycolysis E: none of the answers are correct
B: electron transport system
Lipogenesis generally begins with A: amino acids B: acetyl-CoA C: glucose D: succinyl-CoA E: fatty acids
B: acetyl-CoA
Which is the common substrate for mitochondria in the citric acid cycle? A: acetate B: FAD C: cytochromes D: NAD
A: acetate
Identify the molecule labeled "5" A: citric acid B: oxaloacetic acid C: malic acid D: 4 carbon molecule E: fumaric acid
A: citric acid
In oxidative phosporylation, energy for the synthesis of ATP is directly obtained from the A: breaking of the covalent bonds in glucose B: movement of hydrogen ions through channels in the inner mitochondrial membrane C: combination of 2 atoms of hydrogen and 1 atom of oxygen to form water D: oxidation of acetyl-CoA E: splitting of oxygen molecules
B: movement of hydrogen ions through channels in the inner mitochondrial membrane
When chyme arrives in the duodenum, cholecystokinin release triggers the secretion of which enzyme? A: salivary amylase B: pancreatic alpha-amylase C: maltase D: gastric inhibitory peptide
B: pancreatic alpha-amylase
Glucocorticoids have which of the following effects on general peripheral tissues? A: they increase gluconeogenesis B: they increase glycogenolysis C: they increase the conversion of amino acids to pyruvate D: all of the answers are correct E: none of the answers are correct
D: all of the answers are correct
The electron transport system A: receives electrons from coenzymes B: is found on the inner mitochondria membrane C: produces energy that supports the synthesis of ATP D: all of the answers are correct E: none of the answers are correct
D: 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 except to observe A: elevated levels of glucocorticoids B: ketone bodies in his urine C: lowered blood pH D: all of the answers are correct E: none of the answers are correct
D: all of the answers are correct
The largest lipoproteins, __________, are produced by intestinal epithelial cells from the fats in food A: intermediate density lipoproteins B: high density lipoproteins C: very low density lipoproteins D: chylomicrons E: low density lipoproteins
D: chylomicrons
A drug that blocks the action of lipoprotein lipase would A: prolong the circulation time of chylomicrons B: interfere with triglyceride utilization C: all of the answers are correct D: none of the answers are correct
C: all of the answers are correct
The process that catalyzes fatty acids using enzymes that generate acetyl-CoA is called A: lipolysis B: emulsification C: beta oxidation D: oxidative phosphorylation E: lipogenesis
C: beta oxidation
Poisons like cyanide bind to _______ and prevent electron transfer A: enzymes B: acetyl-CoA C: cytochromes D: endoplasmic reticulum E: mitochondria
C: cytochromes
Linoleic acid and linolenic acid are examples of A: lipoproteins B: vitamins C: essential fatty acids D: transport proteins E: essential amino acids
C: essential fatty acids
All of the following take place during the absorptive state except A: blood lipid levels rise B: insulin stimulates glycogenesis C: ketone bodies begin to form D: estrogen promotes protein synthesis E: blood glucose levels rise
C: ketone bodies begin to form
____________ creates 90% of the ATP normally generated A: the electron transport system B: lipogenesis C: oxidative phosphorylation D: transamination E: glycolysis
C: oxidative phosphorylation
Glycolysis breaks down glucose into what? A: phosphate B: glutaraldehyde C: pyruvate D: citric acid E: NADH
C: pyruvate
There are _______ essential amino acids that the body either cannot synthesize or that cannot be produced in amounts sufficient for growing children A: 2 B: 6 C: 8 D: 10 E: 20
D: 10
Cells synthesize new organic components for which of the following reasons? A: growth and repair B: production of secretions C: structural maintenance D: all of the answers are correct E: none of the answers are correct
D: all of the answers are correct
All of the following are reasons why glucose is the primary energy source for cells except A: glycogen breakdown involves only a single enzymatic step B: glycolysis does not require oxygen to generate ATP C: glucose is small, soluble molecule D: glycogen breakdown occurs very slowly E: glucose can be stored efficiently
D: glycogen breakdown occurs very slowly
Which condition results when body fluids become saturated with uric acid? A: keto acidosis B: phenylketonuria C: kwashiorkor D: gout
D: gout
Urea is formed in the A: large intestine B: stomach C: small intestine D: liver E: kidneys
D: liver
In the ETS, _________ accepts electrons from one molecule and transfers them to another A: a hydrogen ion B: a coenzyme C: a cytochrome D: the acetyl group E: a coenzyme or a cytochrome
E: a coenzyme or a cytochrome
Cells must synthesize new organic compounds in order to A: support growth B: perform structural maintenance or repairs C: store nutrient reserves D: produce secretions E: all of the answers are correct
E: all of the answers are correct
Identify the molecule labeled "2" A: hydrogen atoms B: NAD C: FADH2 D: citric acid E: carbon dioxide
E: carbon dioxide
Chylomicrons: A: are lipoproteins lipid protein complexes that contain insoluble lipids B: diffuse into blood capillaries C: diffuse into the hepatic portal vein, after they are released from the intestinal cells by exocytosis D: enter the bloodstream at the inferior vena cava
A: are lipoproteins lipid protein complexes that contain insoluble lipids
The citric acid cycle A: begins with the formation of a molecule of citric acid B: contains enzymes called cytochromes C: consumes two moles of carbon dioxide D: forms acetyl-CoA from glucose 6 phosphate E: directly produces most of the ATP from the catabolism of glucose
A: begins with the formation of a molecule of citric acid
The lipoproteins that carry absorbed lipids from the intestinal tract to the bloodstream are the A: chylomicrons B: very low density lipoproteins C: low density lipoproteins D: high density lipoproteins E: none of the answers are correct
A: chylomicrons
Which is true regarding lipoproteins and lipid transport and distribution? A: Capillary walls contain the enzyme lipoprotein lipase, which breaks down the triglycerides B: the HDLs return the unused cholesterol to the liver, where it is extracted and packaged in new LDLs or excreted with bile salts in bile C: the liver releases high density lipoproteins into the circulation, which deliver cholesterol to peripheral tissues D: the liver absorbs triglycerides and removes the chylomicrons
B: the HDLs return the unused cholesterol to the liver, where it is extracted and packaged in new LDLs or excreted with bile salts in bile
The conversion of ammonia into a less toxic substance produces A: ketone bodies B: urea C: water D: nitrate E: acetyl-CoA
B: urea
When the body is relying on internal energy reserves to continue meeting its energy demands, it is in the ___________ state A: starvation B: absorptive C: post absorptive D: preabsorptive E: deprivation
C: post absorptive
The major job of enzymes in oxidative phosphorylation includes all of the following except A: release of hydrogen ions B: ionization of hydrogen atoms C: breaking of carbon carbon covalent bonds D: release of electrons to the first cytochrome of the electron transport chain E: none of the answers are correct
C: the breaking of carbon carbon covalent bonds
Which is a characteristic of oxidative phosphorylation? A: it results in the production of pyruvate B: the diffusion of potassium ions powers the production of ATP C: the stepwise passage of electrons by coenzymes embedded in the cristae of the mitochondrion releases energy D: it occurs in the cytoplasm using a series of enzymatic reactions
C: the stepwise passage of electrons by coenzymes embedded in the cristae of the mitochondrion releases energy
Why is glucose the primary energy source for cells? A: glucose is a large, insoluble molecule B: glycogenesis occurs very quickly, even though it is a very complex pathway C: glycolysis provides a large amount of ATP D: it can be efficiently stored as glycogen, which forms compact, insoluble granules
D: it can be efficiently stored as glycogen, which forms compact, insoluble granules
All of the following occur during the postabsorptive state except that A: glycogenesis occurs in the liver B: lipid mobilization occurs C: ketone bodies may be formed D: levels of blood glucose are elevated E: glycogen is broken down into glucose in the liver
D: levels of blood glucose are elevated
In the post absorptive state of metabolic activity, _________________. A: glucagon inhibits glycogenolysis and gluconeogenesis, primarily in the liver B: androgens, estrogens, and growth hormone also stimulate protein synthesis C: insulin stimulates triglyceride synthesis D: glucocorticoids stimulate the mobilization of lipid and protein reserves
D: glucocorticoids stimulate the mobilization of lipid and protein reserves
The process of synthesizing glucose from noncarbohydrate is called A: glycogenesis B: glycolysis C: glycogenolysis D: gluconeogenesis E: glucose reclamation
D: gluconeogenesis
In most tissues, the transport of glucose into the cell is dependent on the presence of a carrier protein that is stimulated by which of the following? A: pyruvate B: chylomicrons C: lactase D: insulin
D: insulin
Glucose: A: is generally used for catabolism after protein and lipid sources are used B: is absorbed and converted to pyruvate as needed by the liver C: leaves the cytosol of the epithelial cells and reaches the interstitial fluid by simple diffusion D: is transported to the liver by way of the hepatic portal vein
D: is transported to the liver by the way of the hepatic portal vein
Cells perform catabolism to generate ATP, which can be used for A: ion transport B: muscle contraction C: glycogen synthesis D: protein synthesis E: all of the answers are correct
E: all of the answers are correct
Which of the following enhances the effects of glucocorticoids? A: epinephrine B: glucagon C: insulin D: androgens E: growth hormone
E: growth hormone
__________ carry excess cholesterol from peripheral tissues to the liver A: very low density lipoproteins B: very high density lipoproteins C: low density lipoproteins D: intermediate density lipoproteins E: high density lipoproteins
E: high density lipoproteins
Identify the substance labeled "4" A: 4 carbon molecule B: NADH C: citric acid D: FADH2 E: hydrogen atoms
E: hydrogen atoms
The sum of all of the biochemical processes going on within the human body at any given time is called A: catabolism B: oxidative phosphorylation C: anabolism D: glycolysis E: metabolism
E: metabolism
In transamination, the amino group of an amino acid is _______________, yielding a different amino acid A: converted to urea B: transferred to acetyl-CoA C: absorbed by water D: converted ammonia E: transferred to another molecule
E: transferred to another molecule