Exam 2 Flashcards
The enzyme Aldehyde dehydrogenase carries out which of the following reactions?
Select one:
a. Oxidation of aldehyde to acid
b. Reduction of aldehyde to alcohol
a. Oxidation of aldehyde to acid
Which of the following statements is False?
Select one:
a. Oxidases uses atmospheric oxygen for oxidation reactions Incorrect
b. Dehydrogenases uses atmospheric oxygen for oxidation reactions
c. Peroxidases hydrolyzes H2O2 to H2O
d. Catalase hydrolyzes H2O2 to O2 and H2O
b. Dehydrogenases uses atmospheric oxygen for oxidation reactions
Which of the following amino acids will exhibit a hydrophobic interaction between itself and Valine? Select one: a. Lys (Lysine) b. Asp (Aspartic acid) c. Glu (Glutamic acid) d. Ala (Alanine)
d. Ala (Alanine)
Phosphagens acts as which of the following?
Select one:
a. High energy phosphate storage units
b. Low energy phosphate storage units
a. High energy phosphate storage units Correct
Complete hydrolysis of which of the following disaccharides yields a single monosaccharide? Select one: a. lactose b. maltose c. sucrose d. none of these
b. maltose
In an ATP molecule, the heterocyclic base is not made from which of the following amino acid (or which of the following amino acids do not take part in the biosynthesis of a purine molecule)? Select one: a. Gly b. Asp c. Gln d. Asn
d. Asn
A student takes some tablets she is offered at a disco, and without asking what they are she swallows them. A short time later she starts to hyperventilate, and becomes very hot. What is the most likely action of the tablets she has taken?
Select one:
a. An uncoupler of mitochondrial electron transport and oxidative phosphorylation
b. An inhibitor of mitochondrial electron transport
c. An inhibitor of the transport of ADP into mitochondria to be phosphorylated
d. An inhibitor of the transport of ATP out of mitochondria into the cytosol
a. An uncoupler of mitochondrial electron transport and oxidative phosphorylation
In the test for blood glucose which of the following is formed? Select one: a. D-glucitol b. D-gluconic acid c. D-glucuronic acid d. methyl-m-D-glucopyranoside
b. D-gluconic acid
Catalase is used as an enzyme for which of the following type of reaction? Select one: a. H2 + ½ O2 → H2O b. H2 + O2 → H2O2 c. H2O2 + AH2 → 2H2O + A d. 2H2O2 → 2H2O + O2
d. 2H2O2 → 2H2O + O2
Under which of the following conditions can monosaccharides be oxidized to uronic acids? Select one: a. basic b. enzymatic c. acidic d. none of these
b. enzymatic
Catalase is used as an enzyme for which of the following type of reaction?
Select one:
a. H2 + ½ O2 → H2O
b. H2 + O2 → H2O2
c. H2O2 + AH2 → 2H2O + A
d. 2H2O2 → 2H2O + O2
e. None of these
d. 2H2O2 → 2H2O + O2
An enzyme converts Acetyl CoA (CH3-CO-SCoA) into Acetic acid and CoA-SH. Which of the following categories does this enzyme belong to? Select one: a. Oxidoreductase b. Hydrolase c. Lyase d. Ligase
b. Hydrolase
Which of the following statements is false?
Select one:
a. Glucouronic acid is the oxidized product of C#6 of glucose
b. Fructose is not a reducing sugar
c. Gluconate is the oxidized product of C#1 of glucose
d. Mannose is the C-2 epimer of glucose.
b. Fructose is not a reducing sugar
Under which of the following conditions can monosaccharides be oxidized to aldonic acids? Select one: a. acidic b. basic c. neutral d. all of these
b. basic
Which of the following explains why ketoses are reducing sugars?
Select one:
a. Under acidic conditions they are converted to aldoses.
b. Under basic conditions they are converted to aldoses.
c. both a and b
d. neither a nor b
b. Under basic conditions they are converted to aldoses.
Enzyme : L-AMINOACID oxidase is used for which of the following reactions? Select one: a. Oxidation of Purine b. Oxidation of Pyrimidine c. Oxidative deamination of amino acids d. Oxidative amidation of amino acids e. None of these
c. Oxidative deamination of amino acids
Flavoproteins are classified as\_\_\_\_\_\_\_\_\_\_\_ Select one: a. Dehydrogenases b. Oxidases c. Hydroperoxidases d. Oxygeneases e. None of these
b. Oxidases
Reduced production of a and b subunits of HbA results in Select one: a. Methemoglobinemia b. Polycythemia c. Alpha and beta thalassemia d. None of these
c. Alpha and beta thalassemia
Which of the following can denature the disulfide bond in peptides? Select one: a. Heat b. Heavy metal ions c. Urea d. Reducing agents
d. Reducing agents
Which of these statements is NOT correct (or False)?
Select one:
a. Cholesterol is synthesized in the body entirely from AcetylCoA, and cholesterol synthesis in the liver is regulated partly by cholesterol in the diet.
b. Glycolipids are important constituents of nervous tissue such as brain and the outer leaflet of cell membranes.
c. Fluidity of a fatty acid increases with chain length and decreases with increase in the degree of unsaturation.
d. Eicosanoids make up an important group of physiologically and pharmacologically active compounds such as prostaglandins, thromboxanes, leukotrienes and lipoxins.
c. Fluidity of a fatty acid increases with chain length and decreases with increase in the degree of unsaturation.
Which of the following statements is NOT correct (or False)?
Select one:
a. Lipogenesis is regulated at the AcetylCoA carboxylase step by allosteric modifiers.
b. Lipogenesis is carried out by one enzyme system: Fatty acid synthase.
c. Biosynthesis of unsaturated fatty acids is achieved by desaturase and elongase enzymes.
d. Higher animals have d-4,d-5, d-6 and d-9 desaturases and cannot introduce a new double bond beyond d-9 of fatty acid.
b. Lipogenesis is carried out by one enzyme system: Fatty acid synthase.
The D-form of which of the following amino sugars is commonly found naturally? Select one: a. allosamine b. althrosamine c. mannosamine d. none of these
c. mannosamine
Which of the following is the action (or function) of superoxide dismutase? Select one: a. Oxidize Cytochrome c b. Oxidation of superoxide anion radical c. Reduction of superoxide anion radical d. None of the options listed.
b. Oxidation of superoxide anion radical
Which of the following conversions occur in Complex II
Select one:
a. Succinate to fumarate
b. Fumarate to Succinate
c. NADH to NAD
d. FADH2 to FAD
a. Succinate to fumarate
Which of the following statements is False?
Select one:
a. Oxidases uses atmospheric oxygen for oxidation reactions
b. Dehydrogenases uses atmospheric oxygen for oxidation reactions
c. Peroxidases hydrolyzes H2O2 to H2O
d. Catalase hydrolyzes H2O2 to O2 and H2O
b. Dehydrogenases uses atmospheric oxygen for oxidation reactions
Which of the following statements is False?
Select one:
a. NAD+ is generally used for the oxidation of alcohols.
b. FAD is generally used for oxidation by removing 2H’s from adjacent carbon atoms.
c. Cytochromes may also be regarded as dehydrogenases.
d. Peroxidases reduce peroxides using H2O2 as an electron donor as well as acceptor.
d. Peroxidases reduce peroxides using H2O2 as an electron donor as well as acceptor.
Which of the following is true of the spatial distribution of the hydroxyl groups of Beta-D-glucopyranose?
Select one:
a. They are all in axial positions.
b. They are all in equatorial positions.
c. The hydroxyl on C-1 is axial, those on C-2, C-3 and C-4 are equatorial.
d. The hydroxyl on C-1 is equatorial, those on C-2, C-3 and C-4 are axial.
b. They are all in equatorial positions.
Which of the following statements is True?
Select one:
a. Triglycerides contain a glycerol and three fatty acids, where the 3rd fatty acid is unsaturated.
b. Phosphatidic acid contains a glycerol molecule to which two fatty acids are condensed on the 1st and 3rd carbon and the 2nd carbon has a phosphate ester group.
c. Plasmalogens occur in brain and muscle.
d. When phosphatidic acid is condensed with serine, it is referred to as Cephalin.
c. Plasmalogens occur in brain and muscle.
d. When phosphatidic acid is condensed with serine, it is referred to as Cephalin.
When a mutation compromises biologic function of HbA, the condition is termed Select one: a. Homeopathy b. Myoglobinopathy c. Hemoglobinopathy d. Mutaopathy
c. Hemoglobinopathy
If Cytidine diphosphate needs to be converted to Cytidine triphosphate in presence of ATP, which of the following enzymes will help in the conversion? Select one: a. Nucleotide kinase b. Nucleoside diphosphate kinase c. Nucleoside diphosphate phosphatase d. Nucleotide phosphatase
b. Nucleoside diphosphate kinase
Peroxisomes are rich in oxidases and which of the following enzymes? Select one: a. Dehydrogenases b. Oxygenases c. Peroxidase d. Catalase
d. Catalase
Which of the following statement is false?
Select one:
a. Prostaglandins, leukotrienes and thromboxanes can be synthesized from Arachidonic acid.
b. Taurocholate is a derivative of Cholesterol (or synthesized by oxidation of cholesterol).
c. Mineralocorticoids such as Cortisol regulate carbohydrate metabolism.
d. Lecithin is classified as a glycerophospholipid.
c. Mineralocorticoids such as Cortisol regulate carbohydrate metabolism.
Which of the following requires a substrate for the reduction of H2O2 (or uses hydrogen from a substrate for the reduction of H2O2)?
Select one:
a. Hydroperoxidase
b. Catalase
a. Hydroperoxidase
In an ATP molecule, the heterocyclic base is not made from which of the following amino acid (or which of the following amino acids do not take part in the biosynthesis of a purine molecule)? Select one: a. Gly b. Asp c. Gln d. Asn
d. Asn
Where is glycogen stored?
Select one:
a. only in the liver
b. only in the muscles
c. in both liver and muscles, but largely in the liver
d. in both the liver and muscles with approximately equal amounts in both
d. in both the liver and muscles with approximately equal amounts in both
Most biomolecules are Select one: a. Amphiprotic b. Apathetic c. Amphitheatric d. Amphipathic
d. Amphipathic
Which of the following is true of isozymes?
Select one:
a. Their amino acid sequences are mirror images of one another.
b. They are a pair of enzymes which must both be present for enzyme activity to occur.
c. They are different forms of the same enzyme found in different tissues.
d. None of the above is true.
c. They are different forms of the same enzyme found in different tissues.
To decompose H2O2 to H2O, which of the following enzymes would you use? Select one: a. Oxidase b. Dehydrogenase c. Oxygenase d. Hydroperoxidase e. None of these
d. Hydroperoxidase
Enzyme : XANTHINE oxidase is used for which of the following reactions? Select one: a. Oxidation of Purine b. Oxidation of Pyrimidine c. Oxidative deamination of amino acids d. Oxidative amidation of amino acids e. None of these
a. Oxidation of Purine
Oligomycin inhibits which of the following reactions?
Select one:
a. ADP to ATP
b. ATP to ADP
a. ADP to ATP
What reaction occurs when glucose is converted to gluconate? Select one: a. reduction at C-1 b. oxidation at C-1 c. reduction at C-6 d. oxidation at C-6
b. oxidation at C-1
The enzyme aldehyde dehydrogenase uses which of the following combination of amino acids to catalyze its reaction? Select one: a. Cys+Asp b. Cys+Glu c. Glu+Asp d. None of the options listed
b. Cys+Glu
The co-enzyme, NAD+ is classified as which of the following oxido-reductase enzyme? Select one: a. Oxygenase b. Oxidase c. Hydroperoxidase d. Dehydrogenase
d. Dehydrogenase
Which of the following statements is True:
Select one:
a. The oxidative phase of PPP generates NADPH
b. The non oxidative phase of PPP generates NADPH
c. The oxidative phase of PPP generates NADP+
d. The oxidative phase generates Ribose precursors
a. The oxidative phase of PPP generates NADPH
Which of the following statements is NOT correct (or False)?
Select one:
a. Geranyl diphosphate gives rise to Dolichol and Ubiquinone.
b. Mevalonate is the reduced product of HMG CoA.
c. Statins inhibit the action of HMG CoA reductase.
d. Mevalonate is converted to Mevalonate 3-phospho-5-diphosphate and then decarboxylated to Isopentyldisphosphate.
a. Geranyl diphosphate gives rise to Dolichol and Ubiquinone.
Glutathione peroxidase catalyzes which of the following type of reaction? Select one: a. H2 + ½ O2 → H2O b. H2 + O2 → H2O2 c. H2O2 + AH2 → 2H2O + A d. 2H2O2 → 2H2O + O2
c. H2O2 + AH2 → 2H2O + A
Which sugar is the starting material used by plants to synthesize vitamin C? Select one: a. D-fructose b. L-fructose c. D-glucose d. L-glucose
c. D-glucose
Hyaluronic acid is which of the following?
Select one:
a. an oligosaccharide
b. a polymer of D-glucuronic acid only
c. a polymer of N-acetyl-D-glucosamine only
d. a polymer of both D-glucuronic acid and N-acetyl-D-glucosamine
d. a polymer of both D-glucuronic acid and N-acetyl-D-glucosamine
Which of the following statements is False?
Select one:
a. Triglycerides contain a glycerol and three fatty acids, where the 2nd fatty acid is unsaturated.
b. Phosphatidic acid contains a glycerol molecule to which two fatty acids are condensed on the 1st and 2nd carbon and the 3rd carbon has a phosphate ester group.
c. When phosphatidic acid is condensed with Choline, it is referred to as Lecithin.
d. When phosphatidic acid is condensed with Ethanolamine, it is referred to as Lecithin
d. When phosphatidic acid is condensed with Ethanolamine, it is referred to as Lecithin
Cytochrome P450 is classified as which of the following?
Select one:
a. Monooxygenase
b. Dioxygenase
a. Monooxygenase
HIV protease illustrates an example of which of the following type of catalysis? Select one: a. Acid-base catalysis b. Covalent catalysis c. Catalysis by strain d. Catalysis by proximity
a. Acid-base catalysis
Select which one of the following statements is false (or not correct).
Select one:
a. Buffers of human tissue include bicarbonate, proteins, and orthophosphate.
b. A weak acid or a weak base exhibits its greatest buffering capacity when the pH is equal to its pKa plus or minus one pH unit.
c. The isoelectric pH (pI) of lysine can be calculated using the formula (pK2 + pK3)/2.
d. The mobility of a monofunctional weak acid in a direct current electrical field reaches its maximum when the pH of its surrounding environment is equal to its pKA.
d. The mobility of a monofunctional weak acid in a direct current electrical field reaches its maximum when the pH of its surrounding environment is equal to its pKA.
Enzyme : L-Aminoacid oxidase is used for which of the following reactions? Select one: a. Oxidation of Purine b. Oxidation of Pyrimidine c. Oxidative deamination of amino acids d. Oxidative amidation of amino acids
c. Oxidative deamination of amino acids
Chymotrypsin illustrates an example of which of the following types of catalysis? Select one: a. Acid base catalysis b. Covalent Catalysis c. Catalysis by strain d. Catalysis by proximity
b. Covalent Catalysis
Which of the following can cause enzyme activity to either increase or decrease?
Select one:
a. changing the temperature
b. increasing the substrate concentration
c. both a and b
d. neither a nor b
a. changing the temperature
In the citric acid cycle, when Malate is oxidized to Oxaloacetate, which of the following co-enzymes is used?
Select one:
a. NAD+
b. FAD
a. NAD+
An enzyme called as the hydroxylase would be classified as which of the following?
Select one:
a. Monooxygenase
b. Dioxygenase
a. Monooxygenase
Which amino acid has an indole ring in the side chain at the alpha carbon? Select one: a. Ala (Alanine) b. Pro (Proline) c. Trp (Tryptophan) d. Tyrosine
c. Trp (Tryptophan)