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Quiz 7
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Q.1
What is Guanine?
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a) Purine
0%
b) Hormone
0%
c) Enzyme
0%
d) Pyrimidine
Explanation
Answer:(a)
Q.2
Protoplasm is formed of .... .... [ RPMT 1998]
0%
a) O, P, minerals
0%
b) H, C, Iron
0%
c) O, N, Iron
0%
d) O, C, H, N
Explanation
Protoplasm is composed of a mixture of small molecules such as ions, amino acids, monosaccharides and water, and macromolecules such as nucleic acids, proteins, lipids and polysaccharides, which are made up of O, C, N, H Answer : (d)
Q.3
Phosphorus is present in .... .... [ JKCMEE 2005]
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a) Protein
0%
b) DNA
0%
c) RNA
0%
d) Both b and c
Explanation
Phosphorus is present in DNA and RNA DNA and RNA are made from nucleotides, each containing a five-carbon sugar backbone, a phosphate group, and a nitrogen base Answer : (d)
Q.4
In DNA, adenine pairs with ... ... [ MPPMT 1992]
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a) Guanine
0%
b) Thymine
0%
c) Cytosine
0%
d) Uracil
Explanation
The two strands are held together by hydrogen bonds between the bases, with adenine forming a base pair with thymine, and cytosine forming a base pair with guanine. Answer : (b)
Q.5
"Lock and Key" model of enzyme action illustrate that a particular enzyme molecule .... ...[ DPMT 2009]
0%
a) Is destroyed and resynthesized several times
0%
b) reacts at the same rate in all conditions
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c) Interacts with specific type of substrate molecule
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d) Forms a permanent enzyme -substrate complex
Explanation
The size and shape of the substrate determine its attachment to the active site. Lock and key model states that the specific substrate attaches to an active site like a key fits in a specific lock. Answer : (c)
Q.6
Enzymes joining two molecules by establishing covalent bonds are .... .... [ kerala 2002]
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a) Ligase
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b) Transferases
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c) Oxidoreductases
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d) Lyases
Explanation
Ligases are enzymes that are capable of catalyzing the reaction of joining two large molecules by establishing a new chemical bond, generally with concomitant hydrolysis of a small chemical group on one of the bulky molecules or simply linking of two compounds together Answer : (a)
Q.7
Km value of enzyme is substrate concentration at ... ... [ BHU 2001]
0%
a) 1/4 Vmax
0%
b) 2Vmax
0%
c) 1/2 Vmax
0%
d) 4Vmax
Explanation
KM is equal to the substrate concentration at which the reaction rate is half its maximal value. Km is the substrate concentration at which the initial reaction rate is equal to 1/2 Vmax. Answer : (c)
Q.8
Fehling's solution can detect ... .... [ CBSE 2001]
0%
a) Glucose
0%
b) Sucrose
0%
c) Starch
0%
d) Fat
Explanation
Fehling's test is used as a general test for determining monosaccharides and other reducing sugars. Examples of monosaccharides include glucose (dextrose), fructose (levulose), and galactose. Answer : (a)
Q.9
Optimum temperature is the temperature at which an enzyme ... ..
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a) Works at its best
0%
b) Is not destroyed
0%
c) Action is reversed
0%
d) Is inactivated
Explanation
At the optimum temperature, the kinetic energy in the substrate and enzyme molecules is ideal for the maximum number of collisions or Works at its best Answer : (a)
Q.10
Decreasing order concentration of minerals inside cell is .... .. [ Har PMT 1994]
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a) Ca-K-Na
0%
b) K-Ca-Na
0%
c) K-Na-Ca
0%
d) Na-K-Ca
Explanation
Answer : (c)
Q.11
Essential-non-essential amino acid is ... ...[ AMU 2010]
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a) Lysine - Leucine
0%
b) Valine - tyrosine
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c) Methionine - Threonine
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d) Alanine - Cystine
Explanation
Essential amino acids
Non-Essential amino acids
Histidine
Alanine
Isolecucine
Argnine
Leucine
Asparagine
Methionine
Cysteine
Phenylalanine
Glutamic acid
Threonine
Glutamine
Tryptophan
Glycine
Valine
Proline
-- --
Selenocysteine
-- --
Serine
-- --
Tyrosine
Answer : (b)
Q.12
Cellulose is made of ... ... [ AIIMS 2007]
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a) Unbranched chain of glucose molecules linked by α-1, 6 glycosidic bonds
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b) unbranched chain of glucose molecules inked by β-1, 4 glycosidic bonds
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c) Branched chain of glucose molecules having α1, 6 glycosidic bonds at the site of branching
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d) Branched chain of glucose molecules with α-1, 6 glycosidic bonds in the straight chain and β-1, 4 linked bonds at the site of branching
Explanation
Answer : (b)
Q.13
An essential amino acid is ... ... [ AMU 2003 ]
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a) Tryptophan
0%
b) Glycine
0%
c) Lutamine
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d) Tyrosine
Explanation
list of essential amino acids found in your body: Isoleucine Histidine Leucine Methionine Lysine Phenylalanine Tryptophan Threonine Valine Answer : (a)
Q.14
Chemical nature of cellulose is .... .... [ KCET 2004]
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a) Disaccharide
0%
b) Polypeptide
0%
c) Polysaccharide
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d) Polynucleotide
Explanation
Polysaccharide: Any of a class of carbohydrates whose molecules contain chains of monosaccharide molecules. Examples include cellulose, starch, or glycogen. Answer : (c)
Q.15
Quaternary structure of protein ... .... [ WB 2008]
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a) Consists of 4 subunits
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b) Is either α or β
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c) Is unrelated to its functions
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d) Is dictated by primary structure of individual subunits
Explanation
Changes in quaternary structure can occur through conformational changes within individual subunits or through reorientation of the subunits relative to each other. Primary Protein Structure : Sequence of a chain of amino acids Secondary Protein Structure: Local folding of the polypeptide chain into helices or sheets Tertiary Protein Structure : Three-dimensional folding pattern of a protein due to side chain interactions Quaternary Protein Structure : Protein consisting of more than one amino acid chain Answer : (d)
Q.16
Moisturizing gel is extracted from ... ... [ Odisha 2004]
0%
a) Saraca indica
0%
b) Aloe vera
0%
c) Acacia vestita
0%
d) None of the above
Explanation
Aloe vera contains antioxidants, enzymes, Vitamins A and C, and it is highly anti-inflammatory. It can help treat burns, acne and dry skin or it moisturize skin. Answer : (a)
Q.17
One of the following is not a carbohydrate .... .... [ RPMT 1995 ]
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a) Maltose
0%
b) Pepsin
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c) Cellulose
0%
d) Ascorbic acid
Explanation
A carbohydrate is a biomolecule consisting of carbon (C), hydrogen (H) and oxygen (O) atoms, usually with a hydrogen–oxygen atom ratio of 2:1 (as in water) and thus with the empirical formula Cm(H2O)n (where m may be different from n). Pepsin is a stomach enzyme that serves to digest proteins. Answer : (b)
Q.18
Which one is polymerized to yield proteins? ... .... [ DPMT 1999 ]
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a) Amino acids
0%
b) Muramic acid
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c) Monosaccharaides
0%
d) All the above
Explanation
Proteins are linear polymers formed by linking the α-carboxyl group of one amino acid to the α-amino group of another amino acid with a peptide bond (also called an amide bond). Answer : (a)
Q.19
A typical homopolysaccharide is ... .... [ WB 2011]
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a) Starch
0%
b) Lignin
0%
c) Insulin
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d) Suberin
Explanation
Homopolysaccharides are polysaccharides composed of a single type of sugar monomer. Answer : (a)
Q.20
The activity of succinate dehydrogenase is inhibited by ... .... [ AMU 1992]
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a) Malonate
0%
b) Pyruvate
0%
c) Glycolate
0%
d) Phosphoglycerate
Explanation
Malonate is a competitive inhibitor of the enzyme succinate dehydrogenase: malonate binds to the active site of the enzyme without reacting, and so competes with succinate. It resembles the substrate succinate, without a −CH2CH2− group required for dehydrogenation. Answer : (a)
Q.21
Assertion: Enzymes lower the activation energy of the reactant molecule to make the transition into product easier Reason: Enzymes are highly substrate specific ... ... [ AIIMS 2011]
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a) Both Assertion and Reason are true and Reason is the correct explanation of Assertion
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b) The Assertion and Reason are true but Reason is not correct explanation of Assertion
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c) Assertion is true but, Reason is false
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d) Assertion is false but, Reason is true
Explanation
Enzymes lower the activation energy of the reactant molecule to make the transition into product easier is a true statement Enzymes are highly substrate specific iis a true statement But both the satements are not inter dependant Answer : (b)
Q.22
Nomenclature of enzyme consists of ... ... [ Pb PMT 2000 ]
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a) First substrate name and then reaction name
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b) First reaction name and then product name
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c) Only product name
0%
d) Only reaction name
Explanation
An enzyme will interact with only one type of substance or group of substances, called the substrate, to catalyze a certain kind of reaction. Because of this specificity, enzymes often have been named by adding the suffix “-ase” to the substrate’s name (as in urease, which catalyzes the breakdown of urea). Except for some of the originally studied enzymes such as pepsin, rennin, and trypsin, most enzyme names end in "ase". Answer : (a)
Q.23
Km value is dependent upon ... ..[ Har PMT 2003]
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a) Temperature
0%
b) Substrate concentration
0%
c) Enzyme concentration
0%
d) All the above
Explanation
The maximal velocity of the reaction (or maximal rate) Vmax is the rate attained when the enzyme sites are saturated with substrate, i.e. when the substrate concentration is much higher than the KM. The Vmax value depends on environmental conditions, such as pH, temperature and ionic strength Answer : (d)
Q.24
Select the specific base pairs of DNA:
0%
a) Adenine and Cytosine
0%
b) Guanine and Adenine
0%
c) Adenine and Thymine
0%
d) Guanine and Uracil
Explanation
Answer:(c)
Q.25
Which one promotes softening of fruits? ... .. [ kerala 2008]
0%
a) Polygalacturonase
0%
b) Polyethylene glycol
0%
c) Colchicine
0%
d) Cellulase
Explanation
Endogenous plant Polygalacturonase (PGs) works to soften and sweeten fruit during the ripening process. Answer : (a)
Q.26
Which group has the same distance class ... ... [ HPPMT 2001]
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a) Sterols, Waxes, Amino acids, Starch
0%
b) Lipids, RNA, Glycine, Cellulose
0%
c) DNA, RNA, Nucleosides, Nucleotides
0%
d) Ribose, Sucrose, Glucose, Maltose
Explanation
Ribose is a simple sugar and carbohydrate with molecular formula C5H10O5 Sucrose is common sugar. It is a disaccharide, a molecule composed of two monosaccharides: glucose and fructose. Glucose is a simple sugar or monosaccharide. Maltose also known as maltobiose or malt sugar Answer : (d)
Q.27
A unit composed of sugar and nitrogen base linked by glycosidic bond is ... ...[ AIIMS 1997]
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a) Purine
0%
b) Glycoside
0%
c) Nucleoside
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d) Nucleotide
Explanation
Nucleotides are the monomeric units of nucleic acids. A nucleotide is formed from a carbohydrate residue connected to a heterocyclic base by a β-D-glycosidic bond and to a phosphate group at C-5' Answer : (c)
Q.28
Tertiary structure of proteins having amino acid cysteine is achieved through ... ... [ kerala 2003]
0%
a) Ionic bonds
0%
b) Covalent bonds
0%
c) Disulphide bonds
0%
d) Hydrogen bonds
Explanation
The tertiary structure is primarily due to interactions between the R groups of the amino acids that make up the protein. Disulfide bonds, covalent linkages between the sulfur-containing side chains of cysteines, are much stronger than the other types of bonds that contribute to tertiary structure. Answer : (c)
Q.29
Ribose is ... ... [ [ MPPMT 2011]
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a) Monosaccharide
0%
b) Disaccharide
0%
c) Polysaccharide
0%
d) Heteropolymer
Explanation
Ribose is an aldopentose, a monosaccharide containing five carbon atoms Answer : (a)
Q.30
RNA contains ... ..... [ JIPMER 1998]
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a) Hexose sugar
0%
b) Dextrose sugar
0%
c) Ribose sugar
0%
d) Deoxyribose sugar
Explanation
The sugar in RNA is called simply ribose Answer : (c)
Q.31
Membrane permeability is controlled by ... ... [ CPMT 1992]
0%
a) Na+
0%
b) K+
0%
c) Both a and b
0%
d) Ca2+
Explanation
Answer : (d)
Q.32
Enzymes, vitamins and hormones are common in ... ... [ BHU 1997]
0%
a) Being proteinaceous
0%
b) Being synthesised in the body of organisms
0%
c) Enhancing oxidative metabolism
0%
d) Regulating metabolism
Explanation
When Ca2+ was present at both sides of the membrane, Na+ efflux was not affected as compared to that in the absence of Ca2+ The Ca2+ outside effect is due to binding of calcium to negatively charged phospholipids with a consequent reduction of both fluidity and Na+ permeability of the membrane. The Ca2+ inside effect most likely involves interaction with proteins with consequent increase in Na+ permeability. Answer : (d)
Q.33
Lipids are insoluble in water as they are .... ... [ CBSE 2002]
0%
a) Hydrophilic
0%
b) Hydrophobic
0%
c) Zwitterions
0%
d) Neutral
Explanation
The carboxyl end of the fatty acid is highly polar and therefore water soluble (hydrophilic meaning attracted to water). Hydrocarbon chain of the fatty acid is highly non-polar and therefore water insoluble (hydrophobic, which means scared of water) Answer : (c)
Q.34
Which one is the hydrogen acceptor? .... .... [ AFMC 1991]
0%
a) CoA
0%
b) NADP+
0%
c) ATP
0%
d) DNA
Explanation
NADP+, picks up a high energy electron and a proton and is converted to NADPH. When NADPH gives up its electron, it is converted back to NADP+. Answer : (b)
Q.35
Major role of minor elements inside living organisms is to act as .... ..... [ CBSE 2003]
0%
a) Cofactor of enzymes
0%
b) Binder of cell structure
0%
c) Constituent of hormones
0%
d) Building blocks of amino acids
Explanation
A cofactor is a non-protein chemical compound or >metallic ion that is required for an enzyme's activity as a catalyst, a substance that increases the rate of a chemical reaction. Metal ions are common cofactors.In humans this list commonly includes iron, magnesium, manganese, cobalt, copper, zinc, and molybdenum. Answer : (a)
Q.36
A substance unrelated to substrate but capable of reversibly changing active site is called .... .. [ JKCMEE 2003]
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a) Competitive inhibitor
0%
b) Non-competitive inhibitor
0%
c) Catalytic inhibitor
0%
d) Allosteric modulator/inhibitor
Explanation
Answer : (d)
Q.37
Enzyme hexokinase is inhibited by excess glucose 6-P. It is .... ... [ Har.PMT 1996]
0%
a) Competitive inhibition
0%
b) Feed-back allosteric inhibition
0%
c) Non-competitive inhibition
0%
d) Positive feed-back
Explanation
Feedback inhibition is a form of allosteric regulation in which the final product of a sequence of enzymatic reactions accumulates in abundance. With too much of this product produced, the final product binds to an allosteric site on the first enzyme in the series of reactions to inhibit its activity. Hexokinase, the enzyme catalyzing the first step of glycolysis, is inhibited by its product, glucose 6-phosphate Answer : (b)
Q.38
Ribose sugar is not a component of ... ... [ MHT CET 2009]
0%
a) AMP
0%
b) ATP
0%
c) DNA
0%
d) RNA
Explanation
Answer : (c)
Q.39
Which is structural polysaccharide .... ...
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a) Glycogen
0%
b) Chitin
0%
c) Keratin
0%
d) Pectin
Explanation
Ribose, found in RNA, is a "normal" sugar, with one oxygen atom attached to each carbon atom. Deoxyribose, found in DNA, is a modified sugar, lacking one oxygen atom (hence the name "deoxy"). Answer : (b)
Q.40
A nucleoside is formed of ... .... [ BHU 2000]
0%
a) Pentose sugar, phosphate and nitrogen base
0%
b) Phosphate and nitrogen base
0%
c) Pentose sugar and phosphate
0%
d) Pentose sugar and nitrogen base
Explanation
Each nucleotide subunit is composed of a pentose sugar (deoxyribose), a nitrogenous base, and a phosphate group. Answer : (d)
Q.41
Molecules having charged group of opposite polarity are .... ... [ DPMT 2010]
0%
a) Zwitterions
0%
b) Anions
0%
c) Cations
0%
d) Negative ions
Explanation
A zwitterion is a molecule with functional groups, of which at least one has a positive and one has a negative electrical charge. The net charge of the entire molecule is zero. Amino acids are the best-known examples of zwitterions. Answer : (a)
Q.42
Sulphur containing amino acid is ... ... [ WB 2008]
0%
a) Methionine
0%
b) Cystine
0%
c) Cysteine
0%
d) All the above
Explanation
Methionine is a unique amino acid it contains sulfur and can produce other sulfur-containing molecules in the body. Cystine is a sulfur-containing amino acid obtained by the oxidation of two cysteine molecules which are then linked via a disulfide bond. Cysteine is amino acids that contains sulfur Answer : (d)
Q.43
Sucrose is ... ..... [ Odisha 2007]
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a) Monosaccharaide
0%
b) Disaccharide
0%
c) Trisaccharide
0%
d) Polysaccharide
Explanation
Sucrose is common sugar. It is a disaccharide, a molecule composed of two monosaccharides: glucose and fructose. Answer : (b)
Q.44
Iodine test can detect ... .. [ KCET 1993]
0%
a) Carbohydrates
0%
b) Nucleic acids
0%
c) Lipids
0%
d) Proteins
Explanation
The iodine-starch test is a chemical reaction that used to test for the presence of starch or for iodine. Answer : (a)
Q.45
In the genera formula of amino acid stated below. Here R stands for ... ...
0%
a) An amino acid
0%
b) A carboxylic group
0%
c) A variable group
0%
d) A hydroxyl group
Explanation
a variable radical -R, that is the functional group of the amino acid. Answer : (c)
Q.46
An important step in the manufacture of pulp in paper industry from woody tissues of plants is ... .... [ CBSE 2005]
0%
a) Preparation of pure cellulose by removing lignin
0%
b) Treatment of wood with chemicals for breakdown of cellulose
0%
c) Removal of oil by suitable chemicals
0%
d) Removal of water from wood by prolonged heat at 50°C
Explanation
Cellulose fiber is the most basic and important constituent of paper, and the size and quality of cellulose fibers are important considerations in the papermaking process. cellulose is extracted from wood through the Kraft pulping process, which involves the semi-chemical degradation of the lignin/hemicellulose matrix by treatment with solutions of sodium hydroxide and sodium sulfide at high temperatures and pressures. Answer : (b)
Q.47
An enzyme brings about ... .... [ CBSE 1993]
0%
a) Decrease in reaction time
0%
b) Increase in reaction time
0%
c) Increase in activation energy
0%
d) Reduction in activation energy
Explanation
The enzyme-substrate complex lower activation energy by bending substrate molecules in a way that facilitates bond-breaking, helping to reach the transition state. Answer : (d)
Q.48
Lipids provide insulation against cold and hot weather to exoskeleton of insects in form of
0%
a) cutin
0%
b) waxes
0%
c) cholesterol
0%
d) oil
Explanation
Answer:(b)
Q.49
Joining of repeating units to fom a macromolecule is called ... ... [ Pb PMT 1997]
0%
a) Polymerization
0%
b) Aggregation
0%
c) Polymorphism
0%
d) Condensation
Explanation
polymerization , is a process of reacting monomer molecules together in a chemical reaction to form polymer chains or three-dimensional networks Answer : (a)
Q.50
Single letter symbol F is used for the amino acid ... ... [ BHU 1993]
0%
a) Phenylalanine (Phe)
0%
b) Proline (Pro)
0%
c) Tryptophan (Try)
0%
d) Methionine (Met)
Explanation
Abbreviation
1 letter abbreviation
Amino acid name
Ala
A
Alanine
Arg
R
Arginine
Asn
N
Asparagine
Asp
D
Aspartic acid
Cys
C
Cysteine
Gln
Q
Glutamine
Glu
E
Glutamic acid
Gly
G
Glycine
His
H
Histidine
Ile
I
Isoleucine
Leu
L
Leucine
Lys
K
Lysine
Met
M
Methionine
Phe
F
Phenylalanine
Pro
P
Proline
Pyl
O
Pyrrolysine
Ser
S
Serine
Sec
U
Selenocysteine
Thr
T
Threonine
Trp
W
Tryptophan
Tyr
Y
Tyrosine
Val
V
Valine
Asx
B
Aspartic acid or Asparagine
Glx
Z
Glutamic acid or Glutamine
Xaa
X
Any amino acid
Xle
J
Leucine or Isoleucine
Answer : (a)
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