Exam 2 Flashcards
(145 cards)
1
Q
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
a. Oxidation of aldehyde to acid
2
Q
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
A
b. Dehydrogenases uses atmospheric oxygen for oxidation reactions
3
Q
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)
A
d. Ala (Alanine)
4
Q
Phosphagens acts as which of the following?
Select one:
a. High energy phosphate storage units
b. Low energy phosphate storage units
A
a. High energy phosphate storage units Correct
5
Q
Complete hydrolysis of which of the following disaccharides yields a single monosaccharide? Select one: a. lactose b. maltose c. sucrose d. none of these
A
b. maltose
6
Q
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
A
d. Asn
7
Q
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
a. An uncoupler of mitochondrial electron transport and oxidative phosphorylation
8
Q
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
A
b. D-gluconic acid
9
Q
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
A
d. 2H2O2 → 2H2O + O2
10
Q
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
A
b. enzymatic
11
Q
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
A
d. 2H2O2 → 2H2O + O2
12
Q
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
A
b. Hydrolase
13
Q
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.
A
b. Fructose is not a reducing sugar
14
Q
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
A
b. basic
15
Q
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
A
b. Under basic conditions they are converted to aldoses.
16
Q
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
A
c. Oxidative deamination of amino acids
17
Q
Flavoproteins are classified as\_\_\_\_\_\_\_\_\_\_\_ Select one: a. Dehydrogenases b. Oxidases c. Hydroperoxidases d. Oxygeneases e. None of these
A
b. Oxidases
18
Q
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
A
c. Alpha and beta thalassemia
19
Q
Which of the following can denature the disulfide bond in peptides? Select one: a. Heat b. Heavy metal ions c. Urea d. Reducing agents
A
d. Reducing agents
20
Q
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.
A
c. Fluidity of a fatty acid increases with chain length and decreases with increase in the degree of unsaturation.
21
Q
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.
A
b. Lipogenesis is carried out by one enzyme system: Fatty acid synthase.
22
Q
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
A
c. mannosamine
23
Q
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.
A
b. Oxidation of superoxide anion radical
24
Q
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
a. Succinate to fumarate
25
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
26
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.
27
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.
28
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.
29
```
When a mutation compromises biologic function of HbA, the condition is termed
Select one:
a. Homeopathy
b. Myoglobinopathy
c. Hemoglobinopathy
d. Mutaopathy
```
c. Hemoglobinopathy
30
```
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
31
```
Peroxisomes are rich in oxidases and which of the following enzymes?
Select one:
a. Dehydrogenases
b. Oxygenases
c. Peroxidase
d. Catalase
```
d. Catalase
32
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.
33
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
34
```
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
35
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
36
```
Most biomolecules are
Select one:
a. Amphiprotic
b. Apathetic
c. Amphitheatric
d. Amphipathic
```
d. Amphipathic
37
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.
38
```
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
39
```
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
40
Oligomycin inhibits which of the following reactions?
Select one:
a. ADP to ATP
b. ATP to ADP
a. ADP to ATP
41
```
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
42
```
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
43
```
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
44
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
45
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.
46
```
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
47
```
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
48
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
49
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
50
Cytochrome P450 is classified as which of the following?
Select one:
a. Monooxygenase
b. Dioxygenase
a. Monooxygenase
51
```
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
52
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.
53
```
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
54
```
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
55
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
56
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+
57
An enzyme called as the hydroxylase would be classified as which of the following?
Select one:
a. Monooxygenase
b. Dioxygenase
a. Monooxygenase
58
```
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)
59
ATP synthase conducts which of the following reactions?
Select one:
a. ATP to ADP
b. ADP to ATP
b. ADP to ATP
60
```
Which of the following reactions occur in Complex IV?
Select one:
a. Reduction of H2O
b. Oxidation of O2
c. Reduction of O2
d. Reduction of CytC
```
c. Reduction of O2
61
Which one of the following statement is False (or not correct)
Select one:
a. Interconvertible enzymes fulfill key roles in integrated regulatory networks.
b. Phosphorylation of an enzyme often alters its catalytic effiiciency.
c. The ability of protein kinases to catalyze the reverse reaction that removes the phosphoryl group is key to the versatility of this molecular regulatory mechanism.
d. Zymogen activation by partial proteolysis is irreversible under physiological conditions
d. Zymogen activation by partial proteolysis is irreversible under physiological conditions
62
```
Which of the following is considered a high energy phosphate compared to ATP?
Select one:
a. Glucose 6-phosphate
b. PPi
c. Creatine phosphate
d. Glycerol 3-phosphate
```
c. Creatine phosphate
63
```
Complex I oxidizes which of the following molecules?
Select one:
a. NADH
b. FADH2
c. FAD
d. NAD+
```
a. NADH
64
I need to isolate Alanine from the following tetrapeptide: AlnylSerylValylGlycine. Which enzyme would I use?
Select one:
a. Carboxypeptidase
b. Aminopeptidase
b. Aminopeptidase
65
```
Cytochrome aa3 is classified as which of the following?
Select one:
a. Oxidase
b. Oxygenase
c. Hydroperoxidase
d. None of the options listed
```
a. Oxidase
66
```
Which types of amino acids interact most strongly with metal ions?
Select one:
a. those with acidic side chains
b. those with basic side chains
c. those with nonpolar side chains
d. those with polar side chains
```
a. those with acidic side chains
67
```
The hydrogen bond in the a-helix is between which two species
Select one:
a. CO and NH
b. CO and CO
c. CO and H
d. NH and NH
```
a. CO and NH
68
```
How many chiral carbons are present in the open-chain form of an aldopentose?
Select one:
a. 2
b. 3
c. 4
d. 5
```
b. 3
69
```
The greatest quantitative source of ATP is which of the following?
Select one:
a. Citric acid cycle
b. Glycolysis
c. Oxidative phosphorylation
d. None of the options listed.
```
c. Oxidative phosphorylation
70
Which of the following is true about the reducing properties of sugars?
Select one:
a. All monosaccharides and all disaccharides are nonreducing sugars.
b. All monosaccharides and all disaccharides are reducing sugars.
c. All disaccharides and some monosaccharides are nonreducing sugars.
d. All monosaccharides and some disaccharides are reducing sugars.
d. All monosaccharides and some disaccharides are reducing sugars.
71
Cytochrome P450 is classified as a ________________________
Select one:
a. Monoxygenase
b. Dioxygenase
a. Monoxygenase
72
Consider the Bohr’s effect exhibited by Hemoglobin. Which of the following is true for Hemoglobin?
Select one:
a. Increase in [CO2] and decrease in pH value will help buffering action.
b. Amino acid His-146 on the alpha chain gets protonated and forms a salt bridge with the amino acid, Asp.
c. There are 2 moles of protons being transported by His-146 on the alpha chain.
d. Decrease in [CO2] and increase in pH value will help buffering action.
d. Decrease in [CO2] and increase in pH value will help buffering action.
73
In the citric acid cycle, which of the following statement is true?
Select one:
a. NADH is used in the process of oxidation of Malate to Oxaloacetate.
b. FAD is used in the process of reduction of succinate to fumarate
c. Malate dehydrogenase, isocitrate dehydrogenase and succinate dehydrogenase all use NAD+ for oxidation/reduction reactions.
d. NAD+ is used for the oxidation of Isocitrate to Oxalosuccinate (or ketoglutarate)
d. NAD+ is used for the oxidation of Isocitrate to Oxalosuccinate (or ketoglutarate)
74
Which of the following determines blood type B in the ABO blood typing system?
Select one:
a. the presence of only N-acetyl-D-galactosamine antigen
b. the presence of only D-galactose antigen
c. the presence of both N-acetyl-D-galactosamine and D-galactose antigens
d. the absence of both N-acetyl-D-galactosamine and D-galactose antigens
b. the presence of only D-galactose antigen
75
```
Which of the following amino acids not only has a 2o amine group attached directly to the alpha carbon but is also hydroxylated in collagen?
Select one:
a. His (Histidine)
b. Pro (Proline)
c. Val (Valine)
d. Arg (Arginine)
```
b. Pro (Proline)
76
```
Which carbon is the site of reaction when fructose reacts to form a fructoside?
Select one:
a. C-1
b. C-2
c. C-5
d. C-6
```
b. C-2
77
Which of the following generally refers to beta bends or turns?
Select one:
a. Joining of two polypeptide beta pleated sheets with 4 aminoacyl residues
b. Joining of two polypeptide beta pleated sheets with more than 4 aminoacyl residues
a. Joining of two polypeptide beta pleated sheets with 4 aminoacyl residues
78
```
Which of the following is associated with noncompetitive inhibition?
Select one:
a. allosterism
b. allotropism
c. isomerization
d. racemization
```
a. allosterism
79
Which of the following statements is false?
Select one:
a. Lysophosphatidylcholine is choline where the #2 Fatty acid has been hydrolyzed by an enzyme.
b. Phosphotidylinositol 4,5bisphosphate is hydrolyzed into diacylglycerol (DAG) and inositol triphosphate (IP3) which act as secondary messengers.
c. Polymerization of isoprene unit results in formation of the polyprenoid tail of CoQ, long chain alcohol, Dolichol and cholesterol.
d. Gangliosides are glycosphingolipids containing Neuraminic acid (NeuAc) and is present in nervous tissues in low concentration.
d. Gangliosides are glycosphingolipids containing Neuraminic acid (NeuAc) and is present in nervous tissues in low concentration.
80
Select which one of the following statements is False (or not correct).
Select one:
a. If the pKa of a weak acid is 4.0, 50% of the molecules will be in the dissociated state when the pH of the surrounding environment is 4.0.
b. A weak acid with a pKa of 4.0 will be a more effective buffer at pH 3.8 than at pH 5.7.
c. At a pH equal to its pI a polypeptide carries no charged groups.
d. The pKa of an ionizable group can be influenced by the physical and chemical properties of its surrounding environment.
c. At a pH equal to its pI a polypeptide carries no charged groups.
81
```
Which of the following co-enzyme is used by an enzyme system that reduces a substrate by transferring hydrogen’s from one substrate to O2?
Select one:
a. NAD
b. NAD+
c. NADH + H+
d. FAD
e. FADH2
```
d. FAD
82
```
Complex II refers to which of the following enzyme system?
Select one:
a. NADH-Q oxidoreductase
b. Q-Cyt C oxidoreductase
c. Cyt C oxidase
d. None of the options listed
```
d. None of the options listed
83
```
2,3-BPG forms what kinds of bonds to stabilize itself with the beta chain of deoxyhemoglobin?
Select one:
a. Metal ion co-ordination
b. Covalent bond formation
c. Electrostatic forces of attraction
d. Hydrogen bonds
```
c. Electrostatic forces of attraction
84
Which of the following statements is false?
Select one:
a. 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.
b. Arachidonic acid contains 20 C’s, 4 DBs, starting at C-5, C-8, C-11 and C-14 from the COOH group.
c. Bile acids are derived from cholesterol or oxidation products of cholesterol.
d. Glycolipids contain a sphingosine molecule to which is attached a fatty acids at the amine group and a phosphate and a choline molecule at the primary alcohol.
d. Glycolipids contain a sphingosine molecule to which is attached a fatty acids at the amine group and a phosphate and a choline molecule at the primary alcohol.
85
```
An alpha 1 → 2 glycosidic bond is found in which of the following?
Select one:
a. lactose
b. maltose
c. sucrose
d. none of these
```
c. sucrose
86
In which case is the hydrogen bond oriented perpendicular to the backbone of the polypeptide (or forms a more regular structure)?
Select one:
a. Antiparallel beta sheet
b. Parallel beta sheet
a. Antiparallel beta sheet
87
Which of the following is true of enzymes?
Select one:
a. They lower the activation energy for a chemical reaction.
b. They speed up the rate of a chemical reaction.
c. both a and b
d. neither a nor b
c. both a and b
88
Which of the following determines blood type A in the ABO blood typing system?
Select one:
a. the presence of only N-acetyl-D-galactosamine antigen
b. the presence of only D-galactose antigen
c. the presence of both N-acetyl-D-galactosamine and D-galactose antigens
a. the presence of only N-acetyl-D-galactosamine antigen
89
Which of the following statements is NOT correct (or False)?
Select one:
a. Cystolic Thiolase catalyzes the condensation of two moles of acetylCoA into acetoacetylCoA.
b. HMG-CoA synthase catalyzes the condensation of AcetoacetylCoA with another mole of AcetoAcetylCoA to form HMG CoA.
c. HMG CoA lyase catalyzes the removal of AcetylCoA from HMGCoA.
d. Cholesterol synthesis is regulated by HMG CoA reductase.
b. HMG-CoA synthase catalyzes the condensation of AcetoacetylCoA with another mole of AcetoAcetylCoA to form HMG CoA.
90
Which of the following is true?
Select one:
a. Both competitive and noncompetitive inhibition are never reversible.
b. Both competitive and noncompetitive inhibition are sometimes reversible.
c. Only competitive inhibition is sometimes reversible.
d. Only noncompetitive inhibition is sometimes reversible.
b. Both competitive and noncompetitive inhibition are sometimes reversible.
91
Which of the following statements about ATP is False?
Select one:
a. It contains two phosphoric anhydride groups
b. It contains two phosphate ester groups
c. The ribose sugar is connected to the N-9 carbon of the heterocyclic base
d. The Phosphoric anhydride group is stabilized by Mg+2 ion
b. It contains two phosphate ester groups
92
```
Which of the following co-enzyme is used by an enzyme system that reduces a substrate by transferring hydrogen’s from one substrate to another?
Select one:
a. NAD
b. NAD+
c. NADH + H+
d. FAD
e. FADH2
```
? I think FAD, but it says its wrong.
93
Assume that the phosphorylation of serine is an endergonic reaction with a value of 8 kJ/mole. To which of the following reactions does it need to couple for the reaction to happen (or proceed)?
Select one:
a. Hydrolysis of Creatine phosphate with a value of -10.3 kJ/mole
b. Hydrolysis of Glucose 1P with a value of -5.0 kJ/mole
c. Hydrolysis of ATP to AMP with a value of – 7.7
d. Hydrolysis of ATP to ADP with a value of -7.3 kJ/mole
a. Hydrolysis of Creatine phosphate with a value of -10.3 kJ/mole
94
```
Which of the following reagents is capable of hydrolyzing glycosides?
Select one:
a. acids
b. bases
c. water
d. all of these
```
a. acids
95
```
What reaction occurs when glucose is converted to glucitol?
Select one:
a. reduction at C-1
b. oxidation at C-1
c. reduction at C-6
d. oxidation at C-6
```
a. reduction at C-1
96
Which of the following is the reason that trypsin is synthesized as trypsinogen?
Select one:
a. It is simpler to synthesize trypsinogen.
b. Trypsinogen is a more active enzyme than trypsin.
c. Trypsin would attack the body's natural proteins.
d. Trypsin is a larger molecule than trypsinogen.
c. Trypsin would attack the body's natural proteins.
97
Which of the following conversions is conducted by Myokinase?
Select one:
a. 2ADP --> ATP+AMP
b. AMP + ATP --> 2ADP
c. ATP + AMP → 2ADP
d. None of the options listed
c. ATP + AMP → 2ADP
98
```
Replacing the 6th amino acid of the beta chain of Glu of HbA with Val results in which of the following disease?
Select one:
a. Polycythemia
b. Hemoglobin M
c. Methemoglobinemia
d. Sickle Cell anemia
```
d. Sickle Cell anemia
99
Which of the following statements is NOT correct (or False)?
Select one:
a. Linoleic and alpha Lenolenic acids are the only fatty acids known to be essential fatty acid.
b. Arachidonic acid can be derived from linoleic acid, in most mammals.
c. The first double bond introduced into a saturated fatty acid is nearly always in the delta-5 (5th position).
d. Plants can synthesize nutritionally essential fatty acids by introducing double bonds at delta-9 (9th carbon) and delta-12 (12th carbon)
c. The first double bond introduced into a saturated fatty acid is nearly always in the delta-5 (5th position).
100
```
Which of the following is the greatest quantitative source of the phosphate group?
Select one:
a. Oxidative phosphorylation
b. Glycolysis
c. Citric acid cycle
d. Phosphagens
```
a. Oxidative phosphorylation
101
```
Which of the following is used by the Cytochrome P450 system (or which of the following is used for anabolic reactions)?
Select one:
a. NAD+
b. NADPH
c. FAD
d. NADH
```
b. NADPH
102
```
One mole of QH2 reduces how many moles of CytC?
Select one:
a. One
b. Two
c. Three
d. Four
```
b. Two
103
```
Which of the following amino acids has a pyrrolidine side chain?
Select one:
a. Lysine
b. Arginine
c. Histidine
d. Proline
```
d. Proline
104
```
Tyrosine-tRNA synthetase belongs to which group of enzymes?
Select one:
a. hydrolases
b. ligases
c. oxidoreductases
d. transferases
```
b. ligases
105
```
In oxidative phosphorylation, ATP synthase produced how many moles of ATP ?
Select one:
a. 1 mole
b. 2 moles
c. 3 moles
d. 4 moles
```
c. 3 moles
106
Which of the following statements is NOT correct (or false)?
Select one:
a. 2 moles of AcetylCoA is required to produce Acetoacetate.
b. Decarboxylation of Acetoacetate produces Acetone.
c. Reduction of acetoacetate produces alpha hydroxybutyrate (or alpha hydroxybutanoate).
d. Ketone bodies serve as fuel for extrahepatic tissues.
c. Reduction of acetoacetate produces alpha hydroxybutyrate (or alpha hydroxybutanoate).
107
```
The CO2 released from tissues and carried by HbA attaches to the N-terminal or the C-terminal of the polypeptide chains?
Select one:
a. N-terminal as carboxylate
b. C-terminal as carboxylate
c. N-terminal as carbamate
d. C-terminal as carbamate
```
c. N-terminal as carbamate
108
Which of the following reactions occur in Complex III?
Select one:
a. Oxidation of Q and reduction of Cyt C
b. Reduction of Cyt C and oxidation of QH2
c. Oxidation of FADH2
d. Oxidation of NADH
b. Reduction of Cyt C and oxidation of QH2
109
Which of the following statements is NOT correct (or false)?
Select one:
a. Carnitine is beta hydroxy-gamma trimethylammonium butyrate.
b. Ketogenesis is regulated at two steps.
c. If Stearic acid is metabolized, 9 AcetylCoA’s are formed along with 8 NADH and 8 FADH2 molecules.
d. Peroxisomes can oxidize the fatty acid - docasahexenoic acid (DHA or Cervonic acid).
b. Ketogenesis is regulated at two steps.
110
```
When a ketohexose such as fructose adopts the furanose structure which atoms are connected by an oxygen atom?
Select one:
a. C-1 and C-5
b. C-1 and C-6
c. C-2 and C-5
d. C-2 and C-6
```
c. C-2 and C-5
111
```
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
112
```
When an aldohexose such as glucose adopts the pyranose structure which atoms are connected by an oxygen atom?
Select one:
a. C-1 and C-5
b. C-1 and C-6
c. C-2 and C-5
d. C-2 and C-6
```
a. C-1 and C-5
113
```
If a substrate is oxidized in the absence of oxygen, the oxido-reductase enzyme would be classified as which of the following?
Select one:
a. Oxidase
b. Dehydrogenase
c. Oxygenase
d. Hydroperoxidase
```
b. Dehydrogenase
114
A number of compounds inhibit oxidative phosphorylation—the synthesis of ATP from ADP and inorganic phosphate linked to oxidation of substrates in mitochondriA. Which of the following describes the action of an uncoupler?
Select one:
a. It discharges the proton gradient across the mitochondrial outer membrane.
b. It inhibits the electron transport chain directly by binding to one of the electron carriers in the mitochondrial inner membrane.
c. It discharges the proton gradient across the mitochondrial inner membrane.
a. It discharges the proton gradient across the mitochondrial outer membrane.
115
```
The formation of a glycoside from a sugar is an which of the following reactions?
Select one:
a. condensation
b. hydrolysis
c. reduction
d. oxidation
```
a. condensation
116
```
In which of the following complexes (or enzymes complexes) is the Q (Ubiquinone or Co-Q) reduced?
Select one:
a. Complex I and II
b. Complex I, II and III
c. Complex I, II, III and IV
d. Complex III and IV
```
a. Complex I and II
117
```
H2S, CO and Cyanide inhibit which of the following complexes?
Select one:
a. Complex I
b. Complex II
c. Complex III
d. Complex IV
```
d. Complex IV
118
```
Which of the following amino acids has an aliphatic side chain?
Select one:
a. Serine
b. Threonine
c. Asparagine
d. Isoleucine
```
d. Isoleucine
119
```
Which types of amino acids interact most strongly with metal ions?
Select one:
a. those with acidic side chains
b. those with basic side chains
c. those with nonpolar side chains
d. those with polar side chains
```
a. those with acidic side chains
120
```
Which one of the following enzymes uses molecular oxygen as a hydrogen acceptor?
Select one:
a. Cytochrome c oxidase
b. Isocitrate dehydrogenase
c. Catalase
d. Superoxide dismutase
```
a. Cytochrome c oxidase
121
```
When an aldopentose such as ribose adopts the furanose structure which atoms are connected by an oxygen atom?
Select one:
a. C-1 and C-3
b. C-1 and C-4
c. C-2 and C-3
d. C-2 and C-4
```
b. C-1 and C-4
122
Which of the following statements is False?
Select one:
a. Long chain omega-3 fatty acids promote the synthesis of less inflammatory prostaglandins and leukotrienes.
b. Phophatidylcholine plays a role in programmed cell death (apoptosis).
c. Peroxidation of lipids containing saturated fatty acids lead to a generation of free radicals that damage tissue and cause disease.
d. Lecithin is a condensation product of phosphatidic acid and Choline.
c. Peroxidation of lipids containing saturated fatty acids lead to a generation of free radicals that damage tissue and cause disease.
123
```
Which of the following is commonly associated with protein modification?
Select one:
a. phosphorylation
b. dephosphorylation
c. both a and b
d. neither a nor b
```
c. both a and b
124
```
In which of the following is the Histidine (His F8) replaced by tyrosine?
Select one:
a. Methemoglobinemia
b. Thalassemias
c. Hemoglobin S
d. Hemoglobin M
```
d. Hemoglobin M
125
```
How many chiral carbons are present in the open-chain form of a ketohexose?
Select one:
a. 3
b. 4
c. 5
d. 6
```
a. 3
126
```
Glycosides are examples of which class of compounds?
Select one:
a. acetals
b. hemiacetals
c. ethers
d. esters
```
a. acetals
127
ATP+CoASH+Fatty Acid -> AMP+PPi+RCO-SCoA (AcylCoA). This conversion is conducted by which of the following enzymes?
Select one:
a. Acetyl-CoA synthetase
b. Acyl-CoA synthetase
b. Acyl-CoA synthetase
128
Which of the following is true of the alpha and beta anomers of glucose?
Select one:
a. They both rotate light to the right (i.e. +), but not to the same extent.
b. They are equally stable.
c. both a and b
d. neither a nor b
a. They both rotate light to the right (i.e. +), but not to the same extent.
129
Which of the following statements is NOT correct (or False)?
Select one:
a. Ketone bodies are formed in hepatic mitochondria when there is a low rate of fatty acid oxidation.
b. Diseases associated with fatty acid oxidation lead to hypoglycemia and hypoketonemia.
c. Fatty acid oxidation in mitochondria leads to the generation of large quantities of ATP by beta oxidation process.
d. Ketosis is mild in starvation but severe in diabetes mellitus and ruminant ketosis.
a. Ketone bodies are formed in hepatic mitochondria when there is a low rate of fatty acid oxidation.
130
```
Which of the following amino acids from an enzyme can exhibit protein modification?
Select one:
a. Met
b. Ser
c. Phe
d. Lys
```
b. Ser
131
```
Acetylcholinesterase belongs to which group of enzymes?
Select one:
a. hydrolases
b. lyases
c. oxidoreductases
d. transferases
```
a. hydrolases
132
```
Which of the following has the highest free energy of hydrolysis?
Select one:
a. Creatine Phosphate
b. Glucose 6P
c. Phosphoenol pyruvate
d. PPi
```
c. Phosphoenol pyruvate
133
Which of the following statements is false?
Select one:
a. Collagen is not synthesized as a larger precursor.
b. Alzheimer’s disease is related to refolding or misfolding of another protein endogenous to human brain tissue, beta amyloiD.
c. Beta thalassemias are caused by genetic defects that impair the synthesis of one of the polypeptide subunits of hemoglobin.
d. Prion diseases may manifest themselves as infectious, genetic or sporadic disorders.
a. Collagen is not synthesized as a larger precursor.
134
```
Which of the following reacts with sugars to form glycosides?
Select one:
a. alcohols
b. amines
c. hemiacetals
d. water
```
Select one:
| a. alcohols
135
```
Including pairs of enantiomers, how many different 2-ketohexoses are there?
Select one:
a. 2
b. 4
c. 8
d. 16
```
c. 8
136
Which of the following is true of glucitol?
Select one:
a. It exists only as an open-chain structure.
b. It exists only as a ring structure.
c. It exists as both ring and open-chain structures with the open-chain structure predominating.
d. It exists as both ring and open-chain structures with the ring structure predominating.
a. It exists only as an open-chain structure.
137
```
Which of the following are components of glycoproteins, gangliosides and glycosaminoglycans?
Select one:
a. Glucitol
b. Glucouronic acid
c. Glucosamine
d. Gluconate
```
b. Glucouronic acid
138
```
When glucose adopts a pyranose structure which carbon is the anomeric carbon?
Select one:
a. C-1
b. C-2
c. C-5
d. C-6
```
a. C-1
139
```
Competitive inhibition can be explained by which of the following models?
Select one:
a. the induced fit model
b. the lock and key model
c. both a and b
d. neither a nor b
```
c. both a and b
140
Which of the following statements is True?
Select one:
a. Lysophosphatidylcholine is choline where the #1 Fatty acid has been hydrolyzed by an enzyme.
b. Phosphotidylinositol 4,5bisphosphate is hydrolyzed into diacylglycerol (DAG) and inositol phosphate (IP) which act as secondary messengers.
c. Cholesterol synthesis starts with 3 moles of AcetylCoA that condense to form HMG CoA (3-hydroxy-3-methylglutaryl CoA).
d. Gangliosides are glycosphingolipids containing Neuraminic acid (NeuAc) and is present in nervous tissues in low concentration.
c. Cholesterol synthesis starts with 3 moles of AcetylCoA that condense to form HMG CoA (3-hydroxy-3-methylglutaryl CoA).
141
```
The enzyme that reduces ½ O2 to H2O by oxidation of a substrate, would be classified as which of the following?
Select one:
a. Oxidase
b. Dehydrogenase
c. Peroxidase
d. Catalase
```
d. Catalase?
142
```
Which of the following amino acids has a benzene and a pyrrole ring fused together and can be used to make serotonin?
Select one:
a. Isoleucine (Ile)
b. Tryptophan (Trp)
c. Histidine (His)
d. None of these
```
b. Tryptophan (Trp)
143
```
The porphyrin ring around the central Fe atom in hemoglobin is also called as the
Select one:
a. Tripyrrole
b. Tetrapyrrole
c. Pentapyrrole
d. Tetrapyrrolidine
```
b. Tetrapyrrole
144
Which of the following statements is true?
Select one:
a. Citrate synthase (oxaloacetate to citrate) is classified as an Oxidoreductase
b. Fumarase (Fumarate to Malate) is classified as ligase Incorrect
c. Succinate thiokinase (Succinyl CoA to Succinate) is classified as a hydrolase and a transferase
d. Malate Dehydrogenase (Malate to oxaloacetate) is classified as a transferase.
c. Succinate thiokinase (Succinyl CoA to Succinate) is classified as a hydrolase and a transferase
145
```
What reaction occurs when glucose is converted to glucuronic acid?
Select one:
a. reduction at C-1 Incorrect
b. oxidation at C-1
c. reduction at C-6
d. oxidation at C-6
```
d. oxidation at C-6
