Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Biochemistry > Exam 1 Review > Flashcards

Exam 1 Review Flashcards

1
Q

1 Which of the following statements about proteins is false?
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

A

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

2 2,3-BPG an allosteric molecule, forms what kinds of bonds to stabilize itself with the beta chain of deoxyhemoglobin?
A: Metal ion co-ordination
B: Covalent bond formation
C: Electrostatic forces of attraction D: Hydrogen bonds

A

C

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

I need to isolate Alanine from the following tetrapeptide: AlnylSerylValylGlycine. Which 1/1 enzyme would I use?
A: Carboxypeptidase
B: Aminopeptidase

A

B

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q 
The pI of an amino acid with three ionizable groups is given as 8.0. Which of the following 1/1 is true of the structure of the amino acid?
A: Has a non polar side chain 
B: Has an acidic side chain 
C: Has a basic side chain
D: Has no side chain
A

C

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Which of the following statements is false?
A: Enzymes employ the following mechanisms to facilitate catalysis: proximity, acid-base, strain and covalent catalysis.
B: 2,3-BPG in the central cavity of deoxyHb forms salt bonds with the beta subunits that stabilize deoxyHb.
C: Superoxide dismutase (SOD) reduces superoxide and also reduces the Fe+3 in Cytochrome c.
D: Cytochrome oxidase is not classified as a hemoprotein.

A

D

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Which of the following statements is false? 0/1
A: Prosthetic groups are tightly integrated into an enzyme’s structure B: Cofactors are tightly integrated into an enzyme’s structure
C: Coenzymes are derivatives of B vitamins.
D: Substrates induce conformation changes in enzymes.

A

B

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Which of the following statements if false? 1/1
A: Heme (or protophoryrin ring) is synthesized from Succinyl-CoA and Glyicine.
B: 65% of the enzymes have His-Arg-Cys-Glu-Asp in the active site.
C: Hemoglobin can be given as an example of a molecule that exhibits allosterism.
D: Bohr’s effect is observed in both Myoglobin and Hemoglobin.

A

D

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Which of the following statements is false?
A: Arginine is used to make NO (Nitric oxide) by the action of NO Synthase.
B: Cysteine participates in the biosynthesis of Coenzyme A
C: Decarboxylation of amino acid, His forms Histamine
D: Amino acid, Tyr is used by neural cells to form only norepinephrine and not epinephrine.

A

D

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Which of the following statements is false?
A: Glycine+Lysine+S-Adenosylmethionine can be used to make Creatine.
B: Serotonin can be made by decarboxylation of 5-hydroxytrytophan.
C: Melatonin is a derivative of (or can be synthesized from) amino acid, Tyr.
D: Melatonin is synthesized by Acetylation of the amine group and methylation of the hydroxyl group of Serotonin.

A

NOT D or A?

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Which of the following statements is false?
A: Amino acid, Cys can be used to synthesize Taurine.
B: Amino acid, Phe can be used to synthesize Catecholamines.
C: Amino acid, Glu can be used to synthesize GABA (Gamma aminobutyrate)
D: Amino acid, Trp can be used to synthesize Catecholamines.

A

D

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q 
In Oxidative phosphorylation process, which of the following complexes does not have the 0/1 potential to push protons into the intermembrane space?
A: Complex I 
B: Complex II 
C: Complex III 
D: Complex IV
A

B

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

When ethanol is added to water, which of the following statements about the effect of the 1/1 dielectric constant and pKa represents a true statement?
A: The pKa of carboxylic acid increases and that of amine decreases
B: The pKa of carboxylic acid decreases and that of amine increases
C: The pKa of carboxylic acid decreases and that of amine decreases
D: The pKa of carboxylic acid increases and that of amine increases

A

A

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

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 oligomycin?
A: It discharges the proton gradient across the mitochondrial inner membrane.
B: It inhibits the electron transport chain directly by binding to one of the electron carriers in the mitochondrial inner membrane.
C: It inhibits the transport of ADP into, and ATP out of, the mitochondrial matrix.
D: It inhibits the transport of protons back into the mitochondrial matrix through ATP synthase.

A

D

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Which one of the following statement about cytochromes P450 is False?
A: They are able to accept electrons from either NADH or NADPH.
B: They are found only in the endoplasmic reticulum.
C: They are monooxygenase enzymes.
D: They play a major role in drug detoxification in the liver.

A

B

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Which one of the following statement about cytochromes is False?
A: They are hemoproteins that take part in oxidation-reduction reactions.
B: They are all dehydrogenase enzymes
C: They act as electron carriers in the respiratory chain in mitochondria.
D: They have an important role in the hydroxylation of steroids in the endoplasmic reticulum.

A

B

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q 
Which one of the following enzymes uses molecular oxygen as a hydrogen acceptor? 
A: Cytochrome c oxidase
B: Isocitrate dehydrogenase
C: Homogentisate dioxygenase D: Catalase
E: Superoxide dismutase
A

A

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Which one of the following statement is False?
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

A

D

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Which one of the following statements is False?
A: Steric hindrance by histidine E7 plays a critical role in weakening the affinity of hemoglobin or carbon monoxide (CO).
B: Carbonic anhydrase plays a critical role in respiration by virtue of its capacity to break down 2,3- bisphosphoglycerate in the lungs.
C: Hemoglobin S is distinguished by a genetic mutation that substitutes Glu6 on the â subunit with Val, creating a sticky patch on its sur ace.
D: Oxidation of the heme iron from +2 to the +3 state removes (or disables) the ability of hemoglobin to bind oxygen.

A

B

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Which one of the following statements is False?
A: Many mitochondrial proteins are covalently modified by the acetylation of the epsilon-amino groups of lysine residues.
B: Protein acetylation is an example of a covalent modification that can be “reversed” under physiological conditions. C: Increased levels of acetyl-CoA tend to favor protein acetylation.
D: The side chain of an acetylated lysyl residue is a stronger base than that of an unmodified lysyl residue

A

D

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
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?
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

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Select the one of the following statements is False (or not correct). 0/1
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.

A

C

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Select which one of the following statements is false (or not correct).
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.

A

D

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Select which one of the following statements is False (or not correct).
A: Glycine is not present in regions where a polypeptide forms a sharp bend, reversing the direction of a polypeptide. B: Polypeptides are named as derivatives of the C-terminal aminoacyl residue.
C: The C, N, O, and H atoms of a peptide bond are coplanar.
D: A linear pentapeptide contains four peptide bonds.

A

A

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Which one of the following statements is False (or not correct). The propensity of water molecules to form hydrogen bonds with one another is the primary factor responsible for all of the following properties of water EXCEPT:

A: Its atypically high boiling point.
B: Its high heat of vaporization.
C: Its high surface tension.
D: Its ability to dissolve hydrocarbons.

A

D

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

Which of the following is true about the following isoenzymes?
A: Lactate Dehydrogenase (LDH) has 3 isoenzymes and Creatine Kinase (CK) has five isoenzymes.
B: Levels of LDH isoenzymes help identify a particular injured tissue, while CK-MB has a useful diagnostic window and is found predominantly in the heart and skeletal muscle.
C: In LDH, isozyme I1 or H4 is found predominantly in the liver and isozyme, I5 or M4 is found in the heart.
D: CK-MB is an isoenzyme of CK that has a useful diagnostic window and is found predominantly in the brain tissue.

A

B

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

Consider the Bohr’s effect exhibited by Hemoglobin. Which of the following is true for Hemoglobin?
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.

A

A

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q 
Which of the following amino acids from an enzyme can exhibit regulation of enzyme by a 0/1 category called as protein modification?
A: Met. 
B: Ser. 
C: Phe. 
D: Lys.
A

B

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

In Collagen, protein bound proline and lysine are modified. Which of the following is a post translational modification of lysine?
A: 5-hydroxylysine. B: 4-hydroxylysine. C: 6-hydroxylysine. D: 3-hydroxylysine.

A

A

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q 
HIV protease illustrates an example of which of the following type of catalysis?
A: Acid-base catalysis. 
B: Covalent catalysis.
C: Catalysis by strain.
D: Catalysis by proximity.
A

A

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q 
Chymotrypsin illustrates an example of which of the following types of catalysis?
A: Acid base catalysis. 
B: Covalent Catalysis.
C: Catalysis by strain.
D: Catalysis by proximity.
A

B

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q 
An enzyme converts Acetyl CoA (CH3-CO-SCoA) into Acetic acid and CoA-SH. Which of 0/1 the following categories does this enzyme belong to?
A: Oxidoreductase. 
B: Hydrolase.
C: Lyase.
D: Ligase.
A

B

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q 
Which of the following amino acids has a benzene and a pyrrole ring fused together and can be used to make serotonin?
A: Isoleucine (Ile). 
B: Tryptophan (Trp). 
C: Histidine (His). 
D: Tyrosine (Tyr)
A

B

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q 
Which of the following amino acids not only has a 1o amine group attached directly to the alpha carbon but is also hydroxylated in collagen?
A: His (Histidine) 
B: Pro (Proline) 
C: Val (Valine) 
D: Arg (Arginine)
A

B

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q 
Which amino acid has an indole ring in the side chain at the alpha carbon? 
A: Ala (Alanine).
B: Pro (Proline).
C: Trp (Tryptophan).
D: Tyrosine.
A

C

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q 
Which of the following amino acids will exhibit a hydrophobic interaction between itself 0/1 and Valine?
A: Lys (Lysine)
B: Asp (Aspartic acid) 
C: Glu (Glutamic acid) 
D: Ala (Alanine)
A

D

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q 
Which of the following amino acids can form a covalent bond with another amino acid? 
A: Glycine (Gly).
B: Methionine (Met). 
C: Cysteine (Cys). 
D: Alanine (Ala).
A

C

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

Which of the following statements is False?
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.

A

B

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q 
Which of the following reactions occur in Complex IV?
A: Reduction of H2O.
B: Oxidation of O2.
C: Reduction of O2.
D: Reduction of Cytochrome C.
A

C

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q 
Which of the following conversions occur in Complex II
A: FAD to FADH2.
B: Fumarate to Succinate. 
C: NADH to NAD.
D: FADH2 to FAD.
A

D

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

The greatest quantitative source of ATP is which of the following?
A: Citric acid cycle.
B: Glycolysis.
C: Oxidative phosphorylation.
D: Hydrolysis of Creatine phosphate to Creatine.

A

C

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
41
Q

The enzyme Aldehyde dehydrogenase carries out which of the following reactions?
A: Oxidation of aldehyde to acid.
B: Reduction of aldehyde to alcohol.

A

A

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
42
Q

The co-enzyme, NAD+ is classified as which of the following oxido-reductase enzyme? 1/1
A: Oxygenase.
B: Oxidase.
C: Hydroperoxidase. D: Dehydrogenase

A

D

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
43
Q

Peroxisomes are rich in oxidases and which of the following enzymes? 1/1
A: Dehydrogenases. B: Oxygenases.
C: Peroxidase.
D: Catalase.

A

D

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
44
Q

Which of the following statements is False?
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.

A

D

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
45
Q

In which of the following complexes (or enzymes complexes) is the Q (Ubiquinone or Co-Q) reduced?
A: Complex I and II.
B: Complex I, II and III.
C: Complex I, II, III and IV. D: Complex III and IV.

A

A

46
Q

In the citric acid cycle, which of the following statement is true?
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).

A

D

47
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)?
A: Gly B: Asp C: Gln D: Asn

A

D

48
Q

Which of the following statements about toxins in the oxidative phosphorylation process is true?
A: H2S, CO, CN- ion inhibit Complex III.
B: Barbiturates inhibit electron transport via Complex I.
C: Malonate is a non competitive inhibitor for Complex III.
D: Oligomycin blocks reduction and phosphorylations reactions in ATP synthas

A

B

49
Q

Glutathione peroxidase catalyzes which of the following type of reaction? 1/1
A: H2 + 1⁄2 O2 → H2O
B: H2 + O2 → H2O2
C: H2O2 + AH2 → 2H2O + A D: 2H2O2 → 2H2O2 + O2

A

C

50
Q

Flavoproteins (FAD, FMN) are classified as___________ 1/1
A: Dehydrogenases B: Oxidases
C: Hydroperoxidases D: Oxygeneases

A

B

51
Q

Enzyme : Xanthine oxidase is used for which of the following reactions?
A: Oxidation of Purine
B: Oxidation of Pyrimidine
C: Oxidative deamination of amino acids D: Oxidative amidation of amino acids

A

A

52
Q

Enzyme : L-Aminoacid oxidase is used for which of the following reactions?
A: Oxidation of Purine
B: Oxidation of Pyrimidine
C: Oxidative deamination of amino acids D: Oxidative amidation of amino acids

A

C

53
Q

Cytochrome P450 is classified as which of the following? A: Monooxygenase
B: Dioxygenase

A

A

54
Q

Cytochrome P450 is classified as ____________________ 1/1
A: Dehydrogenase B: Monooxygenase C: Dioxygenase
D: Hydroperoxidase

A

B

55
Q

Cytochrome aa3 is classified as which of the following?
A: Oxidase
B: Oxygenase C: Peroxidase D: Catalase

A

A

56
Q

Complex II refers to which of the following enzyme system?
A: NADH-Q oxidoreductase B: Q-Cyt C oxidoreductase C: Cyt C oxidase
D: Succinate-Q reductase

A

D

57
Q

Which of the following is true of the complexes in the Oxidative phosphorylation process? 1/1
A: Complexes I, III, and IV act as proton pumps. B: Complexes I, II, III and IV act as proton pumps. C: Complex I, II and IV act as proton pumps.
D: Complex II, III and IV act as proton pumps.

A

A

58
Q

Catalase is used as an enzyme for which of the following type of reaction? 1/1
A: H2 + 1⁄2 O2 → H2O
B: H2 + O2 → H2O2
C: H2O2 + AH2 → 2H2O + A D: 2H2O2 → 2H2O + O2

A

D

59
Q

Which of the following descriptions represents Complex IV?
A: In this complex NADH is oxidized to NAD+. The oxidizing agent is CoQ, which is reduced to CoQH2 B: In this complex FADH2 is oxidized to FAD. The oxidizing agent is CoQ, which is reduced to CoQH2. C: In this complex, CoQH2 delivers the electrons to Cytochrome C
D: This complex is also known as cytochrome oxidase

A

D

60
Q

An enzyme called as the hydroxylase would be classified as which of the following? A: Monooxygenase
B: Dioxygenase

A

A

61
Q

Which of the following statements is false?
A: Allosteric enzymes are regulated by molecules called effectors (also called modifiers) that bind non-covalently at a site other than the active site.
B: The regulatory site that binds the effector may be located on a subunit that is not itself catalytic.
C: Effectors are either homotropic (substrate serves as an effector) or heterotropic (effector is different from the substrate).
D: Phosphorylation (addition of the phosphate group) leads to activation of an enzyme only but cannot deactivate an enzyme.

A

D

62
Q

Which of the following will the cause the rate of enzyme activity to first increase and then 0/1 level off?
A: increasing the enzyme concentration B: increasing the substrate concentration C: increasing the temperature
D: increasing the pH

A

B

63
Q

Which of the following is true when you consider the inhibition of enzymes?
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.

A

B

64
Q

Which of the following is true of isozymes (or isoenzymes)?
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: They are different forms of the same enzyme found in the same tissues.

A

C

65
Q

Which of the following statements is false? 1/1
A: In competitive inhibition, the inhibitor molecule fits into the active site cavity in the same way as the substrate does. B: The enzyme succinate dehydrogenase (SDH) is competitively inhibited by malonate (3 carbon dioic acid).
C: In non competitive inhibition, the inhibitor binds itself to a site other than the active site (allosterism), thereby changing the conformation of the active site.
D: Suicide substrates are inhibitory substrate analogs (identical to the substrate).

A

D

66
Q

Which of the following is true of all allosteric enzymes? 0/1
A: They consist of proteins only.
B: They have a nonprotein portion.
C: They have more than one active site on each subunit.
D: Binding at one site affects protein function at a second site.

A

D

67
Q

Which of the following is the reason that trypsin is synthesized as trypsinogen?
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.

A

D

68
Q

Which of the following is commonly associated with protein modification?
A: phosphorylation B: dephosphorylation C: both a and b
D: neither a nor b

A

C

69
Q

Which of the following is associated with noncompetitive inhibition?
A: allosterism B: allotropism C: isomerization D: racemization

A

A

70
Q

Which of the following can cause enzyme activity to either increase or decrease?
A: changing the temperature
B: increasing the substrate concentration C: both a and b
D: neither a nor b

A

A

71
Q

What disease is diagnosed by monitoring amylase activity?
A: hepatitis
B: liver cancer
C: pancreatic disease D: prostate cancer

A

C

72
Q

What disease is diagnosed by monitoring acid phosphatase activity?
A: hepatitis
B: liver cancer
C: pancreatic disease D: prostate cancer

A

D

73
Q

Tyrosine-tRNA synthetase belongs to which group of enzymes? 0/1
A: hydrolases
B: ligases
C: oxidoreductases D: transferases

A

B

74
Q

In which type of inhibition is it not possible to restore the maximum rate of enzyme activity 0/1 by adding additional substrate?
A: cooperative inhibition
B: competitive inhibition
C: noncompetitive inhibition D: selective inhibition

A

C

75
Q

In which type of inhibition does the inhibitor bind to the active site?
A: cooperative inhibition
B: competitive inhibition
C: noncompetitive inhibition D: selective inhibition

A

B

76
Q

In addition to proteins, which type of molecules sometimes function as enzymes? 0/1
A: carbohydrates B: DNA
C: lipids
D: RNA

A

D

77
Q

Competitive inhibition can be explained by which of the following models?
A: the induced fit model B: the lock and key model C: both a and b
D: neither a nor b

A

C

78
Q

Aspartate transaminase belongs to which group of enzymes?
A: hydrolases
B: lyases
C: oxidoreductases D: transferases

A

D

79
Q

Acetylcholinesterase belongs to which group of enzymes?
A: hydrolases
B: lyases
C: oxidoreductases D: transferases



A

A

80
Q 
When blood glucose enter the erythrocytes, it glycates the pendant group of which amino 0/1 acid?
A: Arginine
B: Lysine
C: Glutamine
D: None of these
A

B

81
Q

81 Which of the following about the classification of enzymes is false? 0/1
A: A decarboxylase is classified as a lyase
B: A kinase is classified as a transferase
C: A synthetase is classified as a lyase.
D: A peptidase is classified as a hydrolase.

A

C

82
Q

In the numerous mutations affecting human hemoglobin, reduced production of alpha and 1/1 beta subunits of HbA results in
A: Methemoglobinemia
B: Polycythemia
C: Alpha and beta thalassemia D: Myoglobinuria

A

C

83
Q

In the numerous mutations affecting human hemoglobin, replacing the 6th amino acid of 1/1 the beta chain of Glu of HbA with Val results in which of the following disease?
A: Polycythemia
B: Hemoglobin M
C: Methemoglobinemia D: Sickle Cell anemia

A

D

84
Q

An increased concentration of erythrocytes because of mutations of hemoglobin results in which disease?
A: Methemoglobinemia B: Hemoglobin S
C: Polycythemia
D: Hemoglobin M

A

C

85
Q 
In which of the following mutations is the Histidine (His F8) replaced by tyrosine?
A: Methemoglobinemia B: Thalassemias
C: Hemoglobin S
D: Hemoglobin M
E: None of these
A

D

86
Q

In the Henderson Hasselbach equation, if the [A-] is equal to [HA], which of the following relationship holds true?
A: pH greater than pKa
B: pH less than pKa
C: pH equal pKa
D: No relationship between molar concentration of the ions and pH

A

C

87
Q 
Consider the action of hemoglobin after it releases oxygen. The CO2 released from tissues and carried by HbA attaches to the N-terminal or the C-terminal of the polypeptide chains?
A: N-terminal as carboxylate 
B: C-terminal as carboxylate 
C: N-terminal as carbamate 
D: C-terminal as carbamate
A

C

88
Q 
Consider the action of hemoglobin. 15% of CO2 in the venous blood is carried by deoxyhemoglobin as which of the following functional groups?
A: CO2
B: Carbamate 
C: Carbonate 
D: Bicarbonate
A

B

89
Q

Consider the Citric acid cycle. Which of the following statements is true?
A: Citrate synthase (oxaloacetate to citrate) is classified as an Oxidoreductase
B: Fumarase (Fumarate to Malate) is classified as ligase
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.

A

C

90
Q

The porphyrin ring around the central Fe atom in hemoglobin is also called as the
A: Tripyrrole
B: Tetrapyrrole
C: Pentapyrrole D: Tetrapyrrolidine

A

B

91
Q

Which of the following amino acid combinations can be used as an example of electrostatic interactions?
A: Glutamic acid and Lysine
B: Lysine and Arginine
C: Glutamic acid and Aspartic acid D: None of these

A

A

92
Q

Which of these statements is true?

A: In the protoporphyrin ring, there are two vinyl, two methyl and two propionate groups attached to the heterocyclic group.
B: Oxidation of one of the methyne carbons of the protoporphyrin ring leads to the formation of biliverdin which is a linear molecule that contains two lactam rings in addition to the two heterocyclic groups.
C: Hemoglobin is homotetrameric whose oxidation curve is sigmoidal.
D: 2,3-BPG which stabilizes the T structure of hemoglobin is a reduced product of glyceraldehydes

A

B

93
Q

Which of the following statements is false?
A: In the case of antiparallel beta sheets the hydrogen bonds form a more regular structure (or is oriented perpendicular to the backbone of the polypeptide).
B: There are 4 aminoacyl residues that are present in beta bends that join two polypeptide sheets.
C: Peptide bonds have partial double bond character.
D: In the case of alpha helix, the pendant groups (or side chains) are arranged on the inside of the helix.

A

D

94
Q

The hydrogen bond in the alpha-helix is between which two species
A: CO and NH of every 4th amino acid group in the same chain. B: CO and CO of every 3rd amino acid group in the same chain. C: CO and NH of every 3rd amino acid group in the same chain. D: NH and NH of every 4th amino acid group in the same chain.

A

A

95
Q

Which of the following can denature the disulfide bond in peptides?
A: Heat
B: Heavy metal ions C: Urea
D: Reducing agents

A

D

96
Q

Which of the following amino acids has a pyrrolidine side chain?
A: Lysine B: Arginine C: Histidine D: Proline

A

D

97
Q

Identify the Amino acid that is responsible for PKU

A: His B: Val C: Phe D: Ala

A

C

98
Q

98 Which of the following statements about proteins is false?
A: In the beta sheets, the hydrogen bonds between the carbonyl oxygens and the amide hydrogens of the peptide bonds stabilize the structure.
B: In the alpha helix, the hydrogen bonds between the pendant amide hydrogens and the carbonyl oxygen of every 4th amide bond stabilize the structure.
C: Higher orders of protein structures are stabilized primarily and often exclusively by noncovalent interactions. D: Formation of a disulfide bond involves oxidation of the cysteinyl sulfhydryl groups and require oxygen.

A

B

99
Q

Which of the following statement about amino acids is false?
A: Isoleucine has an aliphatic side chain
B: Glutamine contains an amide group in the side chain C: Threonine has a 2o alcohol group in the side chain D: Asparagine contains the guanidino unit.



A

D

100
Q

Which of the following statement about competitive and non competitive inhibition is False?
A: Pyruvate kinase (PK) is the active form of the enzyme; it is inactivated by phosphorylation to pyruvate kinase phosphate (PKP).
B: Non competitive inhibitors do not interfere with the binding of the substrate to the enzyme.
C: Some inhibitors act by forming covalent bonds with specific groups of enzymes
D: Statin drugs are examples of molecules that exhibit non-competitive inhibition of an enzyme.

A

D

101
Q 
Which of the following amino acids has an acidic side chain?
Select one:
a. Ala
b. Val
c. Gln
d. Glu
A

D

102
Q 
Which of the following amino acids has an aliphatic side chain?
Select one:
a. Serine
b. Threonine
c. Asparagine
d. Isoleucine
A

D

103
Q 
Most biomolecules are
Select one:
a. Amphiprotic
b. Apathetic
c. Amphitheatric
d. Amphipathic
A

D

104
Q 
Complex I oxidizes which of the following molecules?
Select one:
a. NADH 
b. FADH2
c. FAD
d. NAD+
A

A

105
Q 
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
A

C

106
Q 
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
A

C

107
Q 
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)
A

B

108
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

109
Q 
When a mutation compromises biologic function of HbA, the condition is termed
Select one:
a. Homeopathy
b. Myoglobinopathy
c. Hemoglobinopathy 
d. Mutaopathy
A

C

110
Q 
What disease is diagnosed by monitoring acid phosphatase activity?
Select one:
a. hepatitis
b. liver cancer
c. pancreatic disease
d. prostate cancer
A

D

Biochemistry (6 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions