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DEPARTMENT OF MICROBIOLOGY
SEMESTER III : PAPER
BIOCHEMISTRY I
QUESTION BANK
Saranya Rathan
NEHRU ARTS AND SCIENCE COLLEGE
DEPARTMENT OF MICROBIOLOGY
Question Bank
CLASS
: II B.Sc.
SUBJECT TITLE: ALLIED BIOCHEMISTRY I
_________________________________________________________________________
UNIT-I
Carbohydrates: Monosaccharides - Definition, classification, structure and properties. Disaccharides Definition, types, structure and biological importance. Polysaccharides-types and properties.
UNIT-II
Lipids - Definition, Classification and properties of lipids. Types of fatty acids -saturated,
unsaturated and essential fatty acids. Classification and significance of lipoproteins and
phospholipids. Importance of steroids, structure and biological significance of cholesterol.
UNIT-III
Amino acids: Classification of amino acids, essential amino acids, reactions of amino and carboxyl
groups of amino acids. Proteins: Definition, classification and function of Proteins, structural
levels of organization (Preliminary treatment). Denaturation and isoelectric point of proteins.
UNIT-IV
Nucleic acids: Components of DNA and RNA. Double helical structure of DNA. Structure and types
of RNA. Denaturation and renaturation of DNA. Genetic code. Protein synthesis (an outline)
UNIT-V
Enzymes: Classification of enzymes with examples, coenzymes and cofactors (structures not
needed). Active site: Lock and Key model, Induced fit hypothesis. Factors affecting enzyme
activity. Types of inhibition of enzyme action. Chemical and industrial applications of enzymes.
Test Books:
1. Fundamentals of biochemistry – A.C. Deb New Central Book Agency, Calcutta 6th
Edition.
Reference Books:
1. Biochemistry – Lehninger, Nelson, Cox-CBS Publishers
2. Harper’s Biochemistry: R.K. Murray, D.K Granner, P.A. Mayes and U.W.Rodwell –Lange
Medical publications, 23rd edition.
3. Textbook of Medical Biochemistry – Rana Shindae and Chatterjee.
UNIT – I
Part A
1. The general formula of Monosaccharides is
(1) CnH2nOn (2) C2nH2On (3) CnH2O2n (4) CnH2nO2n
2. A pentose sugar is
(1) Dihydroxyacetone (2) Ribose (3) Erythrose (4)Glucose
3. Sucrose consists of
(1) Glucose + glucose (2) Glucose + fructose (3) Glucose + galactose (4) Glucose
+ mannose
4. The number of isomers of glucose is
(1) 2 (2) 4 (3) 8 (4) 16
5. A keto sugar is
(1) Fructose (2) Ribose (3) Erythrose (4) Glucose
6. Starch consists of
(1) Polymer of Glucose (2) Polymer of Glucose + fructose(3) Polymer of Glucose and
galactose (4) Monomer of Glucose
7. The general test for detection of carbohydrates is________
(1) Iodine test (2) Molisch test (3) Barfoed test (4)Osazone test
8. ____________ is a polysaccharide and it is component of cell walls in plants.
(1) Cellulose (2) starch (3) glycogen (4) glucose
9. The substance _______________ is known as animal starch.
(1) Glucose (2) starch (3) glycogen (4) chitin
10. Starch is a
(1) Homopolysaccharide (2) Monosaccharide (3)Disaccharide (4) Heteropolysaccharid
11. The most important epimer of glucose is
(1) Galactose (2) Fructose (3) Arabinose (4) Xylose.
12. The carbon atom present in pentose sugar is _____ carbons
(1) 5 (2) 3 (3) 6 (4) 4
13. All of the following are storage carbohydrates except
(1) Starch (2) Glycogen (3) Amylopectin (4) Cellulose
14. Which of the following is a polysaccharide found in human muscle cells?
(1) Myoglobin (2) Collagen (3) Glycogen (4) Amylose
15. Compounds having the same structural formula but differing in spatial configuration
are known as
(1) Stereoisomers (2) Anomers (3) Optical isomers (4)Epimers
16. Which of the following is a non-reducing sugar?
(1) Isomaltose (2) Maltose (3) Lactose (4) sucrose
17. Lactose consists of
(1) Glucose + glucose (2) Glucose + fructose (3) Glucose + galactose (4) Glucose +
mannose.
18. Maltose consists of
(1) Glucose + glucose (2) Glucose + fructose (3) Glucose + galactose (4) Glucose
+ mannose
19. The polysaccharide found in the exoskeleton of invertebrates is
(1) Pectin (2) Chitin (3) Cellulose (4) Chondroitin sulphate
20. The most abundant carbohydrate found in nature is
(1) Starch (2) Glycogen (3) Cellulose (4) Chitin
21. Iodine gives a blue colour with
(1) Starch (2) Glycogen (3) Cellulose (4) Chitin
22. Amylose is a constituent of
(1) Starch (2) Glycogen (3) Cellulose (4) Chitin
23. A aldotriose sugar is
(1) Glyceraldehyde (2) Ribose (3) Erythrose (4) Fructose
24. Which of the following is a reducing sugar?
(1) glucose (2) fructose (3) Maltose (4) All
25. A carbohydrate, commonly known as dextrose is
(1) Dextrin (2) D-Fructose (3) D-Glucose (4) Glycogen
Part – B
1. Define Carbohydrates and explain their classification with examples.
2. Explain briefly about the properties of Disaccharides
3. Explain about the structure and properties of Monosaccharide’s.
4. Briefly note on structural polysaccharides.
5. Discuss on three hetero polysaccharides with its structure.
Part C
1. Explain in detail about the types of disaccharides, structure and their biological importance.
2. Explain in detail about Polysaccharides-types and properties.
3. Define Carbohydrates? How they are classified? Briefly write on sub classification of
Monosaccharides with example.
4. Describe the disaccharide with suitable example along with its structural illustrations.
5. Briefly note on storage polysaccharides.
6. Explain structure and function of starch and cellulose
UNIT II
Part A
1. Esters of fatty acids with glycerols is
(1) Fats (2) Waxes (3) Lipids (4) None of the above
2. In mammals, the major fat in adipose tissues is
(1) phospholipds (2) cholesterol (3) Sphingolipids (4)Triacylglycerol
3. Which is derived lipid
(1) Triglycerides (2) cholesterol (3) beeswax (4)kerosene
4. The fatty acid containing one or more double bond is called as
(1) Unsaturated fatty acid (2) Saturated fatty acid (3)Essential fatty acid (4) none of the
above
5. Essential fatty acid are
(1) Linoleic acid (2) Linolenic acid (3) Arachidonic acid (4)All these
6. Lipids are stored in the body mainly in the form of
(1) Phospholipids (2) Glycolipids (3) Triglycerides (4)Fatty acids
7. The fatty acid with no bond is called as
(1) Saturated fatty acid (2) Unsaturated fatty acid (3)Essential fatty acid (4) none of
the above
8. A fatty acid which is not synthesized in human body and has to be supplied in the diet is
(1) Palmitic acid (2) Oleic acid (3) Linoleic acid (4)Stearic acid
9. An example of a saturated fatty acid is
(1) Palmitic acid (2) Oleic acid (3) Linoleic acid (4) Erucic acid
10. Higher alcohol present in waxes is
(1) Benzyl (2) methyl (3) ethyl (4) cetyl
11. The highest phospholipids content is found in
(1) chylomicrons (2) VLDL (3) LDL (4) HDL
12. The major lipid in chylomicrons is
(1) Triglycerides (2) Phospholipids (3) Cholesterol (4)Free fatty acids
13. Number of carbon atoms in cholesterol is
(1) 17 (2) 19 (3) 27 (4) 30
14. The nitrogenous base in lecithin is
(1) Ethanolamine (2) Choline (3) Serine (4) Betaine
15. Elevated plasma level of the following projects against atherosclerosis:
(1) Chylomicron (2) VLDL (3) LDL (4) HDL
16. Very low density lipoproteins are also known as
(1) Beta-lipoproteins (2) Pre Beta—lipoproteins (3)alpha-lipoproteins (4) None of these
17. low density lipoproteins are also known as
(1) Beta-lipoproteins (2) Pre Beta—lipoproteins (3) alpha-lipoproteins (4) None of these
18. Cholesterol is a
(1) Animal sterol (2) M.F. C27 H46O (3) 5 methyl groups(4) All of these
19. Biological functions of lipids include
(1) Source of energy (2) Insulating material (3)Maintenance of cellular integrity (4)
All of these
20. Cephalins are composed of
(1) Glycerol + Fatty acids + Phosphoric acid + Choline (2)Glycerol + Fatty acids +
Phosphoric acid + Ethanolamine (3) Glycerol + Fatty acids + Phosphoric acid +
Serine (4) Glycerol + Fatty acids + Phosphoric acid + Beaine
21. Phospholipids are important cell membrane components since
(1) They have glycerol (2) Form bilayers in water (3) Have polar and non-polar
portions (4) Combine covalently with proteins
22. The lipoprotein with the fastest electrophoretic mobility and lowest TG content are
(1) VLDL (2) LDL (3) HDL (4) Chylomicrones
23. The compound which has the lowest density is
(1) Beta-lipoproteins (2) Pre Beta—lipoproteins (3) alpha-lipoproteins (4) Chylomicrone
24. The density of lipoproteins increases as the protein content
(1) Increases (2) decreases (3) Highly decreases (4)Slightly and promptly decrease
25. Which of the following is a polyunsaturated fatty acid?
(1) Palmitic acid (2) Palmitoleic acid (3) Linoleic acid (4)Oleic acid
Part B
1. What are derived lipids? Give some examples.
2. Write a briefly note on steroids.
3. Define phospholipids and write the properties.
4. Explain briefly about Compound lipids and its properties.
5. Briefly explain the properties of lipids?
6. Write in a brief note about cholesterol.
7. Discuss the biological significance of phospholipids.
8. Bring out the structure and biological significance of cholesterol.
Part C
1. How are lipids classified? Briefly explain each group
2. Explain structure and function of starch and cellulose
3. Explain the classification of lipoproteins? Explain structure and functions of any two
disaccharides.
4. Explain about the classification of lipids in detail.
5. Explain in detail on types and properties of fatty acids.
Unit III
Part A
1. Sulphur containing amino acid is
(1) Methionine (2) Leucine (3) Valine (4) Asparagine
2. The chief protein of cow’s milk is
(1) Albumin (2) Vitellin (3) Livetin (4) Casein
3. The protein present in nail is
(1) Keratin (2) Elastin (3) Collagen (4) Myosin
4. Egg contains
(1) Protein (2) fat (3) Carbohydrates (4) calcium
5. Non essential amino acids_______
(1) are not components of tissue proteins (2) Synthesized in the body from essential
amino acids (3) Should be supplemented in diet (4) May be synthesized in the body in
diseased states
6. Primary structure of a protein is formed by
(1) Hydrogen bonds (2) Peptide bonds (3) Disulphide bonds (4) All of these
7. Transfer of amino group from one aminoacid to other aminoacid is called as
(1) transamination (2) deamination (3) transaminidation(4) transamidation
8. Removal of amino group from one aminoacid is called as
(1) transamination (2) deamination (3) transaminidation(4) transamidation
9. Removal of carboxyl group from an aminoacid is called as
(1) transamination (2) deamination (3) decarboxylation(4) transamidation
10. Proteins are
(1) monomer of aminoacid (2) polymer of aminoacid (3)madeup of amino group
and carboxyl group (4) madeup of amino group alone
11. All proteins contain the
(1) Same 20 amino acids (2) Different amino acids (3)300 Amino acids occurring in
nature (4) Only a few amino acids
12. An aromatic amino acid is
(1) Lysine (2) Tyrosine (3) Leucine (4) Arginine
13. An amino acid not found in proteins is
(1) Alanine (2) Proline (3) Lysine (4) Histidine
14. A disulphide bond can be formed between
(1) Two methionine residues (2) Two cysteine residues (3)methionine and a cysteine
residue (4) All of these
15. A Zwitterion is
(1) Positive ion (2) Negative ion (3) Both (a) and (b) (4)None of these
16. Which among the following is a basic amino acid?
(1) Aspargine (2) Arginine (3) Proline (4) Alanine
17. The useful reagent for detection of amino acids is
(1) Molisch reagent (2) Dichlorophenol Indophenol (3)Ninhydrin (4) Biuret
18. Denaturation of proteins leads to loss of biological activity by
(1) formation of amino acid (2) loss of primary structure(3) loss of both primary
and secondary structure (4) loss of secondary and tertiary structure
19. Casein, the milk protein is
(1) Nucleoprotein (2) Chromoprotein (3) Phosphoprotein(4) Glycoprotein
20. In proteins the ?-helix and ?-pleated sheet are examples of
(1) Primary structure (2) Secondary structure (3) Tertiary structure (4) Quaternary
structure
21. Glutelins are present in
(1) Milk (2) Meat (3) Eggs (4) Cereals
22. The most abundant protein in mammals is
(1) Albumin (2) Haemoglobin (3) Collagen (4) Elastin
23. The amino acid which contains an indole group is
(1) Histidine (2) Arginine (3) Glycine (4) Tryptophan
24. One of the following has a phenolic group:
(1) Histidine (2) Hydroxy lysine (3) Seratonine (4)Hydroxy proline
25. The major end product of protein nitrogen metabolism in man is
(1) Glycine (2) Uric acid (3) Urea (4) NH3
Part B
1. Define iso electric point and briefly explain about it.
2. Differentiate essential amino acid from nonessential amino acid.
3. Write a note on protein classification.
4. Give an account protein denaturation.
5. Enlist the reactions carried out by functional group of aminoacids.
6. Write a note on denaturation of proteins and agents responsible for denaturation.
Part C
1. Give an account on classification of aminoacids.
2. Describe the structural level of proteins with suitable diagram.
3. Explain in detail about classification of amino acids based on side chain.
4. Give in detail about the nutritional and functional classification of aminoacids with
example.
5. Illustrate the reactions of amino and carboxyl groups of amino acids.
UNIT IV
Part A
1. The amount of adenine is always equal to the amount of ____ in DNA.
(1) Cytosine (2) uracil (3) guanine (4) thymine
2. The nucleotide consists of
(1) Purine + sugar + phosphorous (2) Purine or pyrimidine base + sugar +
phosphorous (3) Purine or pyrimidine base + sugar (4) Purine or pyrimidine base
+ phosphorous
3. The nucleoside consists of
(1) sugar + phosphorous (2) Purine + pyrimidine base + sugar + phosphorous (3) Purine
or pyrimidine base + sugar (4) Purine or pyrimidine base + phosphorous
4. The sugar found in DNA is
(1) Xylose (2) Ribose (3) Deoxyribose (4) Ribulose
5. RNA does not contain
(1) Uracil (2) Adenine (3) Thymine (4) Ribose
6. The sugar moiety present in RNA is
(1) Ribulose (2) Arabinose (3) Ribose (4) Deoxyribose
7. The structure of tRNA appears like a
(1) Hair pin (2) Helix (3) clover leaf (4) Coil
8. DNA was discovered by
(1) Meischer (2) Watson and Crick (3) Griffith (4) Avery
9. The nucleotide present only in RNA is _______
(1) Cytosine (2) Uracil (3) Guanine (4) Thymine
10. The structure of DNA is
(1) double strand (2) single strand (3) double stranded helical (4) single stranded helical
11. DNA rich in G-C pairs have
(1) 1 (2) 2 (3) 3 (4) 4
12. DNA rich in A-T pairs have
(1) 1 (2) 2 (3) 3 (4) 4
13. The bond between the nucleotide is ______
(1) Hydrogen bond (2) Phosphodiester Bond (3)Phosphate bond (4) covalent bond
14. The nitrogenous bases will be attached to the sugar moiety at the position of ______
(1) 1 (2) 5 (3) 3 (4) 2
15. Difference between the DNA and RNA is ______
(1) Sugar (2) nitrogenous base (3) Both (4) None
16. In DNA 2 strands will be______conformation
(1) parallel (2) antiparallel (3) Same (4) opposite
17. Degeneracy of the genetic code means that
(1) a given base triplet can code for more than one amino acid (2) there is no
punctuation in the code sequence (3)the third base in a codon is net important for coding
(4) a given amino acid can be coded for by more than one base triplet
18. A purine nucleotide is
(1) AMP (2) UMP (3) CMP (4) TMP
19. A pyrimidine nucleotide is
(1) GMP (2) CMP (3) AMP (4) IMP
20. Translation refers to
(1) DNA replication (2) protein synthesis using mRNA and tRNA (3) mRNA synthesis
from DNA (4) converting an inactive protein into its active form
21. Which of the following molecules has an amino acid attached to it?
(1) DNA (2) tRNA (3) mRNA (4) all of the above
22. A codon is
(1) one three-letter “word” in the genetic code (2) a protein cap on the end of a
chromosome. (3) the enzyme that makes DNA replication possible. (4) a special kind
of RNA that provides energy for cell fission.
23. Genetic code is having all the properties except
(1) universal (2) comma less (3) overlapping (4)ambegious
24. Start codon is
(1) UAA (2) AUG (3) UAG (4) UGA
25. Stop codon is
(1) UAA (2) all the three (3) UAG (4) UGA
Part B
1. Describe the structure and types of RNA.
2. DNA is double helical structure in nature - justify.
3. Illustrate the chemistry of DNA molecule
4. Give an account on genetic code and its properties.
5. Write about the components of DNA with structures.
6. Write about the component of RNA.
Part C
1. DNA is double helical structure in nature - justify.
2. Give an account on genetic code and its properties
3. llustrate the structure and types and RNA.
4. Explain in detail about the synthesis of protein.
5. Write in detail about the Nucleic acids.
6. Define – nucleotide and nucleoside and explain in detail.
7. Illustrate the structure of ribosome and its function in detail.
UNIT V
Part A
1. The enzyme found in the tears is
(1) Lysozyme (2) Protease (3) Trypsin (4) Peptidase
2. Ribozymes are
(1) Enzymes which combine the ribosomal subunits (2)Enzymes which
dissociate (3) Enzymes made up of RNA(4) Enzymes present in ribosomes
3. Coenzymes are
(1) Heat stable, dialyzable, non protein organic molecules (2) Soluble, colloidal,
protein molecules (3)Structural analogue of enzymes (4) Different forms of enzymes
4. Factors affecting enzyme activity is
(1) Concentration (2) pH (3) Temperature (4) All of these
5. The enzyme found in the saliva is
(1) Lysozyme (2) Protease (3) Amylase (4) Lipase
6. Two amino acids of the standard 20 contain sulfur atoms. They are:
(1) cysteine and serine (2) cysteine and threonine (3)methionine and
cysteine (4) Methionine and serine
7. Enzymes, which are produced in inactive form in the living cells, are called
(1) Papain (2) Lysozymes (3) Apoenzymes (4)Proenzymes
8. Fischer’s ‘lock and key’ model of the enzyme action implies that
(1) The active site is complementary in shape to that of substance only
after interaction. (2) The active site is complementary in shape to that of
substance (3)Substrates change conformation prior to active site interaction (4) The
active site is flexible and adjusts to substrate
9. In enzyme kinetics Vmax reflects
(1) The amount of an active enzyme (2) Substrate concentration (3) Half the
substrate concentration (4)Enzyme substrate complex
10. An example of enzyme inhibition is
(1) Reversible inhibition (2) Irreversible inhibition (3)Allosteric inhibition (4) All
of these
11. Which is true about enzymes,
(1) they always increase rate of reaction (2) they always decrease rate of reaction (3) they
do not disturb the equilibrium (4) Always carry irreversible reactions
12. Blocking action of enzyme through blocking its active site is
(1) Allosteric inhibition (2) Feedback inhibition (3)Competitive inhibition (4) Noncompetitive inhibition
13. Blocking action of enzyme through blocking other than active site is
(1) Allosteric inhibition (2) Feedback inhibition (3)Competitive inhibition (4) Noncompetitive inhibition
14. An example of ligases is
(1) Succinate thiokinase (2) Alanine racemase (3)Fumarase (4) Aldolase
15. An example of lyases is
(1) Glutamine synthetase (2) Fumarase (3) Cholinesterase(4) Amylase
16. The kinetic effect of purely competitive inhibitor of an enzyme
(1) Increases Km without affecting Vmax (2) Decreases Km without affecting
Vmax (3) Increases Vmax without affecting Km (4) Decreases Vmax without affecting
Km
17. In reversible non-competitive enzyme activity inhibition
(1) Vmax is increased (2) Km is increased (3) Km is decreased (4) Concentration
of active enzyme is reduced
18. The induced fit model of enzyme action was proposed by
(1) Fischer (2) Koshland (3) Mitchell (4) Markert
19. Competitive inhibition can be relieved by raising the
(1) Enzyme concentration (2) Substrate concentration(3) Inhibitor
concentration (4) None of these
20. An enzyme is a
(1) Carbohydrate (2) Lipid (3) Protein (4) Nucleic acid
21. In normal resting state of human most of the blood glucose burnt as fuel is consumed by
(1) Liver (2) Brain (3) Adipose tissue (4) Muscles
22. Feedback inhibition of enzyme is influenced by
(1) Enzyme (2) External factors (3) End product (4)Substrate
23. Characteristic features of active site are
(1) Flexible in nature (2) Site of binding (3) Acidic (4) Both (a) and (b)
24. The enzyme used in baby foods preparation is__________
(1) Lysozyme (2) Protease (3) Trypsin (4) Peptidase
25. Enzyme involved in joining together two substrates is
(1) ligase (2) Hydrolase (3) Lyase (4) Transferase
Part B
1. Define active site? Explain the models proposed for binding of substrate with enzyme.
2. Explain about Lock and key model.
3. Explain in detail about induced fit model.
4. Give any 5 Chemical and industrial applications of enzymes.
5. Explain about the cofactor
6. Explain brief about the coenzymes.
Part C
1. Analyze the factors affective enzyme activity.
2. Explain about the mechanism of enzyme inhibition and inhibitors.
3. Give an account on classification of enzymes with example.
4. Write in detail about the factors affecting enzyme activity.
5. Write in detail about the types of inhibition of enzyme action.