NEET Biology Chapter Wise Mock Test – Biomolecules and Enzymes
1. Which of the following is not correct?
(a) Plant cell wall is made up of cellulose
(b) Paper made from plant pulp is cellulose
(c) Cotton fibre is cellulose
(d) Cellulose gives blue-colour with iodine test
2. Exoskeletons of arthropods consist of complex polysaccharide called chitin. These complex polysaccharides are
(c) glucose polymers
(d) fructose polymers
3. Which of the following is correct?
(a) Peptide bond is the linkage between two amino acids of protein
(b) Glycosidic bond is the linkage between two monosaccharides in a polysaccharide
(c) Phosphodiester bond is the linkage between two nucleotides
(d) All of the above
4. It is said that elemental composition of living organisms and that of inanimate objects (like earth’s crust) are similar in the sense that all the major elements are present in both. Then what would be the difference between these two groups? Choose a correct answer from among the following
(a) Living organisms have more gold in them than inanimate objects.
(b) Living organisms have more water in their body than inanimate objects
(c) Living organisms have more carbon, oxygen and hydrogen per unit mass than inanimate objects.
(d) Living organisms have more calcium in them than inanimate objects.
5. The two polynucleotide chains in DNA are
6. Which of the following is not correct?
(a) Peptide bond is formed, when R-group of one amino acid reacts with carboxyl (COOH) group of another amino acid
(b) Glycosidic bond is formed by dehydration between two carbon atoms of two adjacent monosaccharides
(c) The bond between the phosphate and hydroxyl group of sugar is an ester bond
(d) None of the above
7. Which of the following is not correct about DNA structure?
(a) DNA double helical model was proposed by Watson and Crick
(b) Two strands of DNA are antiparallel, i.e., run in opposite directions .
(c) The DNA backbone is formed by the sugar-phosphate- sugar chain
(d) There are three hydrogen bonds between A and T, while two between G and C
8. Many elements are found in living organisms either free or in the form of compounds. One of the following is not found in living organisms.
9. One turn of the helix in a B-form DNA is approximately
(c) 3.4 nm
(d) 2 nm
10. GLUT-4 is a protein, which
(a) fights against infectious agents
(b) enables glucose transport into cells
(c) acts as enzyme
(d) acts as hormone
11. Which of the following macromolecules constitute the major portion of cellular mass?
(d) Nucleic acids
12. The most important form of energy currency in living systems is the bond energy in a chemical called
13. Feedback inhibition of caused by
(c) end product
(d)rise in temperature
14. Amino acids as the name- suggests have both an amino group and a carboxyl in their structure. In addition, all naturally occurring amino acids (those which are found in protiens) are called L-amino acids. From this, can you guess from which compound can the simplest amino acid be made?
(a) Formic acid
15. Which of the following is not correct?
(a) All proteins are enzymes
(b) Almost all enzymes are proteins
(c) Ribozymes are catalytic nucleic acids (RNA)
(d) An enzyme like any protein have primary structure, i.e. amino acid sequence of the protein
16. An active site
(a) is a site on enzyme into which the substrate fits
(b) is a site on carbohydrates into which the enzyme fits
(c) slows the speed of catalysis
(d) stops the speed of catalysis
17. Enzymes get damaged at high temperatures above
18. RNA and DNA are similar in
(a) having similar sugars
(b) having similar pyrimidine base
(c) being capable to replicate’
(d) being polymers of nucleotides
19. Enzymes isolated from thermophilic organisms found in hot vents and sulphur springs are stable and retain their catalytic power even at high temperature upto
20. As per rule of thumb, rate of chemical reaction doubles or decreases by half for every
(a) 10°C change in temperatu^
(b) 20°C change in temperature
(c) 30°C change in temperature
(d) 40°C change in temperature
21. Oxygenic compounds of biological process which activate chemical reactions are
22. Many organic substances are negatively charged e.g., acetic acid, while others are positively charged e.g., ammonium ion. An amino acid under certain conditions would have both positive and negative charges simultaneously in the same molecule. Such a form of amino acid is called
(a) Positively charged form
(b) Negatively charged form
(c) Neutral form
(d) Zwitterionic form
23. Which of the following is the first step during enzyme- substrate complex?
(a) Alteration of shape of enzyme
(b) Binding of substrate to the active site of enzyme
(c) Breaking of chemical bonds of substrate
(d) Release of product from enzyme
24. When the binding of the chemical shuts off enzyme activity, the process is called
25. Enzymes that catalyse removal of groups from substrates by mechanisms other than hydrolysis leaving double bonds are
26. Antiparallel strands of a DNA molecule means that
(a) one strand turns anti-clockwise
(b) the phosphate groups of two DNA strands, at their ends, share the same position
(c) the phosphate groups at the started of two DNA strands are in opposite position (pole)
(d) one strand turns clockwise
27. Which of the following reaction is catalysed by hydrolases?
(a) Hydrolysis of ester
(b) Hydrolysis of ether
(c) Hydrolysis of peptides
(d) All of these
28. Hydrogen bonds play an important role in
(b) p-pleated sheets
(c) between two strands of DNA .
(d) All of the above
29. Paraffin wax is
(c) monohydric alcohol
30. An enzyme that can stimulate germination of barley seeds is
31. Which of the following is not correct?
(a) All monosaccharides are reducing sugars
(b) Fehling’s test is used for detecting reducing sugars
(c) Maltose and lactose are non-reducing sugars
(d) Sucrose occurs in sugarcane and sugarbeet, is a non-reducing sugars
32. Maltose or malt sugar is found in
(a) mammary glands
(b) germinated starchy seeds
(c) sugarcane and sugarbeet
(d) All of these
33. Sugars are technically called carbohydrates, referring to the fact that their formulae are only multiple of C(H20). Hexoses therefore have six carbons, twelve hydrogens and six oxygen atoms. Glucose is a hexose Choose from among the following another hexose.
34. Human can not digest cellulose, whereas it is digested by termites and ruminents like sheeps because
(a) termites and sheeps harbour bacteria and protozoans that synthesize the necessary enzyme cellulase
(b) in human, digestion is intracellular
(c) in human, cellulose digesting hormones remain absent
(d) None of the above
35. Chitin is the principal component of the endoskeleton of insects and crustaceans. It is a polymer of
(c) N-acetyl glucosamine
36. Cellulose is a homoglycan hexosan. Almost pure cellulose is found in
37. The figure given below shows three curves i.e. velocity, substrate, concentration curves for an enzyme reaction. What do the curves a, b and c depict respectively?
(a) A-normal enzyme reaction, B-competitive inhibition, G-non-competitive inhibition
(b) 4-enzyme with an allosteric modulator added, B-normal enzyme activity, Ocompetitive inhibition
(c) 4-enzyme with an allosteric stimulus, B-competitive inhibitor added, C-normal enzyme reaction
(d) A-normal enzyme reaction, B-non-competitive inhibitor added, c-allosteric inhibitor added
38. The covalent linkage of a carbohydrate to a protein or lipid is termed as
39. Which of the following is not secondary metabolite?
(b) Tax ol
(c) Amino acid
40. When you take cells or tissue pieces and grind them with an acid in a mortar and pestle, all the small biomolecules dissolve in the acid, Proteins, polysaccharides and nucleic acids are insoluble in mineral acid and get precipitated. The acid soluble compounds include amino acids, nucleosides, small sugars etc. When one adds a phosphate group to a nucleoside one gets another acid soluble biomolecule called
(a) Nitrogen base
(c) Sugar phosphate
41. Which one of the following hydrolyses internal phosphodiester bonds in a polynucleotide chain?
42. Which of the following biomacromolecules is not strictly macromolecule ?
(c) Nucleic acids
43. Protein is
(c)not a polymer
(d)All of these
44.Nucleotide are building blocks of nucleic acids. Nucleotide is a composite molecule formed by
(a) (base – sugar – phosphate)
(b) base – sugar —OH
(c) base – sugar – phosphate
(d) sugar – phosphate
45. The most abundant protein in animal world is
46.Which of the following is the most abundant protein in the whole of the biosphere?
47.DNA of which of the following organisms has no ends?
(a) Human DNA
(b) E. coli DNA
(c) Monkey DNA
(d) Fruit fly DNA
48.DNA molecules that make up the centromere and telomeres are
(a) coding DNA
(b) non-coding DNA
(c) circular DNA
(d) None otthese
49.Which of the following is the simplest amino acid?
50.Carbohydrates, the most abundant biomolecules on earth are produced by
(a) all bacteria, fungi and algae
(b) fungi, algae and green plant cells
(c) some bacteria, algae and green plant cells
(d) viruses, fungi and bacteria
51.Which of the following statements about enzymes is not true?
(a) Competitive inhibitors act away from the active site
(b) Allosteric inhibitors act away from the active site
(c) Allosteric inhibitors can change the size of the active site
(d) Competitive inhibitors usually resemble the substrate In non-competitive inhibition, the allosteric inhibitor
52. In non-competitive inhibition, the allosteric inhibitor
(a) attaches to the substrate, preventing it from attaching to the active site
(b) changes the pH of the environment, thus preventing enzyme-substrate complex formation
(c) causes the substrates to polymerize, preventing individual enzyme-substrate attachment
(d) attaches to the enzyme at a site away from the active site, altering the shape of the enzyme
53.When we homogenise any issue in an acid soluble pool it represents
54.In an endergonic reaction, the products of a reaction contain
(a) more energy than the reactants and energy is released
(b) more energy than the reactants and energy must be supplied
(c) less energy than the reactants and energy is released
(d) less energy than the reactants and energy must be supplied
55.Physicists have defined a formal measure of disorder, called
56. The minimum amount of energy needed for a process to occur is called the
(a) minimal energy
(b) process energy
(c) kinetic energy
(d) activation energy
57. In which of the following enzymes, copper is necessarily associated as an activator?
(a) Carbonic anhydrase
(c) Lactic dehydrogenase
58. Which of the following enzymes would digest a fat?
59. At high temperature, the rate of enzyme action decreases because the increased heat
(a) changes the pH of the system
(b) alters the active site of the enzyme
(c) neutralizes the acids and bases in the system
(d) increases the concentration of the enzyme
60. Enzymes influence chemical reactions in living systems by
(a) providing the substrate required for the reaction to occur
(b) affecting the rate at which reactions occur
(c) absorbing water released when polymers are formed
(d) combining with excess hydrogen to form gaseous wastes
61. Which form of RNA has a structure resembling clover leaf?
62. Which group of organic compounds includes the enzymes?
63. Any substance that is acted upon by an enzyme is called a(n)
64. At 25°C the optimum reaction rate of a certain enzyme occurs at a pH of 7. A greater reaction rate could probably be attained by
(a) increasing the temperature to 35°C and keeping the pH at 7
(b) increasing both the temperature and the pH
(c) decreasing the pH and increasing the temperature
(d) increasing the pH and keeping the temperature at 25°C
65. At about 0°C, most enzymes are
66. Which element is present in maltase, but not in maltose?
67. In enzyme controlled reactions, the role of certain vitamins such as niacin is to act as
(a) an enzyme
(b) a substrate
(c) a coenzyme
(d) a polypeptide
68. Basic structure of protein was given by
(a) WM Stanley
(d) F Sanger
69. Which statement describes the currently accepted theory of how an enzyme and its substrate fit together?
(a) As the product is released, the enzyme breaks down
(b) The enzyme is like a key that fits into the substrate, which is like a lock
(c) The active site is permanently changed by its interaction with the substrate
(d) As the substrate binds to the enzyme, the shape of the enzyme site changes to accommodate the reaction
70. Which statement is not true about the effects of various conditions on the activity of an enzyme?
(a) Higher temperatures generally increase the activity of an enzyme up to a point
(b) Above a certain range of temperatures, the protein of an enzyme is denatured
(c) A change in pH can cause an enzyme to be inactivated
(d) An enzyme’s activity is generally reduced by an increase in substrate concentration
71. Which of the following sugar is found in nucleic acid?
72. The active site of an enzyme
(a) is similar to that of any other enzyme
(b) is the part of the enzyme, where its substrate can fit
(c) can be used over and over again
(d) is not affected by environmental factors like pH and temperature
73. An allosteric site on an enzyme is
(a) the same as the active site .
(b) non-protein in nature
(c) where ATP attaches and gives up its energy
(d) often involved in feedback inhibition
74. The tertiary structure of the proteins containing amino acid cysteine is achieved through
(a) hydrogen bonds
(b) disulphide bonds
(c) covalent bonds
(d) ionic bonds
75. Cellulose is a polymer of
(d) p -fructose
76. Which statement best expresses the information represented in the graph shown?
(a) The action of enzymes varies with pH
(b) A pH of 7 provides the optimum environment for digestive enzymes
(c) Gastric juice is active at a pH extending from 0 to 12
(d) Acids have a pH greater than 7
77. A pure protein should normally have
(a) Two ends
(b) One end
(c) Three ends
(d) No ends
Direction (Q. NOS. 78-82) In each of the following questions a statement of Assertion is given followed by a corresponding statement of Reason just below it. Of the statements, mark the correct answer as
(a) If both Assertion and Reason are true and Reason is the correct explanation of Assertion.
(b) If both Assertion and Reason are true, but Reason is not the correct explanation of Assertion.
(c) If Assertion is true, but Reason is false.
(d) If both Assertion and Reason are false.
78. Assertion The higher the turn-over number, the more efficient an enzyme is.
Reason It is not dependent upon the number of • active sites present over an enzyme.
79. Assertion Arachidic acid is an unsaturated fatty acid.
Reason There are present one or more double bonds between carbon atoms in unsaturated fatty – acids.
80. Assertion Sucrose is a reducing sugar.
Reason All disaccharides are reducing sugars.
81. Assertion A coenzyme or mdtal ion that is very tightly bound to enzyme protein is called prosthetic group.
Reason A complete, catalytically active enzyme together with its bound prosthetic group is called apoenzyme.
82. Assertion Enzymes are defined as biological catalytic proteins.
Reason Chemically, all enzymes are globular proteins.
83. Match the following columns.
Column 1 Column II
A. Carbonic anhydrase 1. Sugar alcohol
B. Creatinine phosphate 2. Non-reducing sugar
C. Mannitol 3. High energy phosphate
D. Sucrose 4. Reducing sugar
5. Red blood cells
A B C D
(a) 5 3 1 2
(b) 1 2 3 4
(c) 2 13 4
(d) 5 4 1 2
84. Match the following columns.
Column 1 Column II
A. fRNA 1. Linking of amino acids
B. mRNA 2. Transfer of genetic information .
C. rRNA 3. Nucleolar organising region
D. Peptidyl transferase 4. Transfer of amino acid from cytoplasm of ribosome
A BCD A B C D
(a) 4 2 3 1 (b) 1 4 3 2
(c) 1 2 3 4 (d) 13 2 4
85.Select the option which is not correct with respect to enzyme action.
(a) Substrate binds with enzyme at its active site
(b) Addition of lot of succinate does not reverse the inhibition of succinic dehydrogenase by malonate
(c) A non-competitive inhibitor binds the enzyme at a site distinct from that which binds the substrate
(d) Malonate is a competitive inhibitor of succinic dehydrogenase
86. Which one of the following is a non-reducing carbohydrate?
87. The essential chemical components of many coenzymes are
(a) Nucleic acids
88. A phosphoglyceride is always made up of
(a) only an unsaturated fatty acid esterified to a glycerol molecule to which a phosphate group is also attached.
(b) a saturated or unsaturated fatty acid esterified to a glycerol molecule to which a phosphate group is also attached
(c) a saturated or unsaturated fatty acid esterified to a phosphate group which is also attached to a glycerol molecule
(d) only a saturated fatty acid esterified to a glycerol molecule to which a phosphate group is also attached
89. Macro molecule chitin is
(a) Phosphorus containing polysaccharide
(b) Sulphur containing polysaccharide
(c) Simple polysaccharide
(d) Nitrogen containing polysaccharide
90. Which enzyme/s will be produced in a cell is a nonsense mutation in the lac Y gene?
(a) Lactose permease
(c) Lactose permease and transacetylase
91.Which one out of A-D given below correctly represents the structural formula of the basic amino acid?
92.Which one of the following structural formulae of two organic compounds is correctly identified along with its related function?
(a) A — Triglyceride — major source of energy
(b) B — Uracil — a component of DNA
(c) A — Lecithin — a component of cell membrane
(d) B — Adenine — a nucleotide that makes up nucleic acids
93.Given below is the diagrammatic representation of one of the categories of small molecular weight organic compounds in the living tissue. Identify the . category shown and the one blank component Xin it
(a) Cholesterol Guanine
(b) Amino acid NH2
(c) Nucleotide Adenine
(d) Nucleoside Uracil
94. The curve given below shows enzymatic activity with relation to three conditions (pH, temperature and substrate concentration)
What do the two axises (X and Y)
(a) Temperature – Enzyme activity
(b) Substrate -concentration Enzymatic activity
(c) Enzymatic – activity Temperature
(d) Enzymatic – activity pH
95. Which of the following is an essential fatty acid in mammals?
(a) Stearic acid
(b) Acetic acid
(c) Palmitic acid
(d) Gamma linolenic acid
96.. Even after disruption of all the hydrogens bonds, which structural level of a protein molecule still remains intact
(a) tertiary structure
(b) primary structure
(c) secondary structure
(d) quaternary structure