Question :
31.A urea molecule contains
a.two nitrogen atoms
b.two carbon atoms
c.two hydrogen atoms
d.more : 1309728
31.A urea molecule contains
a.two nitrogen atoms
b.two carbon atoms
c.two hydrogen atoms
d.more than one correct response
e.no correct response
32.Substances to which amino acid carbon “skeletons” may be degraded include
a.acetyl CoA
b.citrate
c.succinate
d.more than one correct response
e.no correct response
33.Carbon-containing amino acid degradation products can be converted to
a.glucose
b.ketone bodies
c.fatty acids
d.more than one correct response
e.no correct response
34.In the first step of the degradation of the heme portion of hemoglobin:
a.Molecular O2 is needed as a reactant.
b.Carbon monoxide is a product.
c.Ring opening with the release of an iron atom occurs.
d.More than one correct response.
e.No correct response.
35.Bile pigments produced from the degradation of the heme portion of hemoglobin are responsible for
a.the yellow color of urine
b.the reddish-brown color of feces
c.the yellow skin color associated with the jaundice condition
d.more than one correct response
e.no correct response
Use the following to answer the questions below:
In each of the following multiple-choice questions, characterize EACH of the three given statements as being TRUE or FALSE and then indicate the collective true-false status of the statements using the choices:
a) All three statements are true.
b) Two of the three statements are true.
c) Only one of the statements is true.
d) None of the statements is true.
36.Statements:
(1) The net effect of protein digestion is the release of the protein’s constituent amino acids.
(2) Ammonium ions enter the urea cycle in the form of carbamoyl phosphate.
(3) Glycogenic amino acids have carbon skeletons that are degraded to glucose.
a.All three statements are true.
b.Two of the three statements are true.
c.Only one of the statements is true.
d.None of the statements is true.
37.Statements:
(1) Excess amino acids are stored in the body for later use in the form of tetra- and pentapeptides.
(2) The ultimate product of all transamination reactions is the amino acid glutamate.
(3) The oxygen atom in urea comes from a water molecule that participates in a hydrolysis reaction.
a.All three statements are true.
b.Two of the three statements are true.
c.Only one of the statements is true.
d.None of the statements is true.
38.Statements:
(1) Protein digestion begins in the stomach rather than the small intestine.
(2) In the second step of heme degradation, biliverdin is converted to bilirubin.
(3) In the oxidative deamination of glutamate, alpha-ketoglutarate is one of the products.
a.All three statements are true.
b.Two of the three statements are true.
c.Only one of the statements is true.
d.None of the statements is true.
39.Statements:
(1) Properties of the compound urea include yellow color, strong odor, and high solubility in water.
(2) The amino group acceptor in most transamination reactions is oxaloacetate.
(3) Absorption of amino acids through the intestinal wall requires active transport.
a.All three statements are true.
b.Two of the three statements are true.
c.Only one of the statements is true.
d.None of the statements is true.
40.Statements:
(1) Citric acid cycle intermediates are often the products from amino acid carbon skeleton degradation.
(2) The net effect of transamination is to collect the amino groups from a variety of amino acids into the amino acids glutamate and aspartate.
(3) All of the reactions of the urea cycle occur within mitochondria.
a.All three statements are true.
b.Two of the three statements are true.
c.Only one of the statements is true.
d.None of the statements is true.
41.Statements:
(1) The source for both nitrogen atoms in a urea molecule is carbamoyl phosphate.
(2) In the second stage of amino acid degradation, ammonium ion is liberated from glutamate through oxidative deamination.
(3) Dietary protein intake and protein turnover are the body’s only sources for providing amino acids for the amino acid pool.
a.All three statements are true.
b.Two of the three statements are true.
c.Only one of the statements is true.
d.None of the statements is true.
42.Statements:
(1) A reactant and a product in the first step of the urea cycle are, respectively, ornithine and citrulline.
(2) Degradation of heme begins with a ring-opening reaction in which carbon monoxide is produced.
(3) With a normal diet, only about 10 percent of our total calories come from protein.
a.All three statements are true.
b.Two of the three statements are true.
c.Only one of the statements is true.
d.None of the statements is true.
43.Statements:
(1) Each of the 20 standard amino acid carbon skeletons undergoes a different degradation process.
(2) The net effect of the urea cycle is the production of urea from ammonium ions and acetyl CoA.
(3) In transamination, the amino group of an amino acid is interchanged with the acid group of an alpha-keto acid.
a.All three statements are true.
b.Two of the three statements are true.
c.Only one of the statements is true.
d.None of the statements is true.
44.Statements:
(1) Stercobilin, a bile pigment, is the substance that gives fecal matter its brown color.
(2) Glycolysis and citric acid cycle intermediates are the starting materials for amino acid biosynthesis.
(3) The urea cycle participants arginine and citrulline are both nonstandard amino acids.
a.All three statements are true.
b.Two of the three statements are true.
c.Only one of the statements is true.
d.None of the statements is true.
45.Statements:
(1) The major organic and inorganic solutes in urine are, respectively, urea and chloride ion.
(2) Nitric oxide is an extremely reactive gaseous chemical messenger in cells that is produced from the reaction of oxygen with the amino acid arginine.
(3) The action of nitroglycerin, as a heart medication, is related to NO production.
a.All three statements are true.
b.Two of the three statements are true.
c.Only one of the statements is true.
d.None of the statements is true.
