MCQ in Biochemistry

1. In double helix of DNA, the two strands are

A. Coiled around a common axis B. Coiled differently C. Coiled over protein sheath D. Coiled around each other 2. Lipids are insoluble in water because lipid molecules are A. Hydrophilic B. Neutral C. Zwitter ions

D. Hydrophobic 3. Lactose is composed of

A. Glucose + galactose B. Fructose + galactose C. Glucose + fructose D. Glucose + glucose 4. Which of the following nucleotide sequences contains four pyrimidine bases?

A. GATCAATGC B. UAGCGGUAA C. GCUAGACAA D. Both B and C 5. The term apoenzyme is applicable to A. Simple enzyme

B. Protein part of conjugate enzyme C. Organic cofactor of a conjugate enzyme D. Inorganic cofactor of conjugate enzyme 6. The enzymes involved in feed back inhibition are called

A. Allosteric enzymes B. Holoenzymes C. Apoenzymes D. Coenzymes 7. Koshland’s theory of enzyme action is known as A. Reduced fit theory

B. Induced fit theory C. Lock and key theory D. Enzyme coenzyme theory 8. Which of the statements is true regarding Km A. It is the measure of the stability of the ES complex B. It is the measure of the stability of the affinity of an enzyme for its substrate C. A high Km indicates weak substrate binding

D. All of these 9. Any molecule which acts directly on an e nzyme to lower its catalytic rate is called A. Regulator

B. Repressor

C. Inhibitor D. Moderator 10. A reversible non-competitive inhibitor binds reversibly at a site other than the active site. This binding lead to A. increase in Km and Vmax remains constant B. Increase in Vmax and Km remain constant

C. Decrease in Vmax and Km remains constant D. No change in Vmax and Km 11. The preferred substrate for hexokinase is

A. Glucose B. Fructose C. Glucose and fructose equally preferred D. Galactose 12. The primary structure of protein represents

A. Linear sequence of amino acids joined by peptide bond B. 3 – dimensional structure of protein C. Helical structure of protein D. Sub unit structure of protein 13. The first protein sequence by Fredrick Sanger is A. Haemoglobin B. Myoglobin C. Myosin

D. Insulin 14. A. dipeptide has

A. 2 amino acids and 1 peptide bond B. 2 amino acids and 2 peptide bonds C. 2 amino acids and no peptide bonds D. 2 amino acids and release of two water molecules 15. α – helix has A. 3.4 amino acid residue/turn

B. 3.6 amino acid residue/turn C. 3.8 amino acid residue/turn D. 3.0 amino acid residue/turn 16. The pentoses in nucleotides are

A. In β – furnaose form B. In α –  furanose form C. Both alpha and beta form D. In pyrnaose form 17. Dehydration of DNA samples may induce the formation of A. A – DNA

B. Z- DNA C. B-DNA D. H-DNA 18. Ribozymes are A. Enzymes with catalytic activity

B. RNA with catalytic activity C. Proteins with catalytic activity D. Nucleic acids with catalytic activity 19. A nucleoside is composed of

A. A base + sugar B. A base + sugar + phosphate C. A base + phosphate D. Sugar + phosphate 20. The length of one turn of DNA is 0

A. 3.4 A

B. 34 A0 C. 20 A

0 0

D. 3.04 A

21. A short length of DNA molecule has 80 thymine and 80 guanine bases. The total number of nucleotide in the DNA fragment is A. 160 B. 40

C. 320 D. 640 22. The synthesis of glucose from fat is called A. Glycolysis B. Kreb’s cycle C. Glycogenesis

D. Gluconeogenesis 23. β – oxidation takes place in

A. mitochondria B. Cytoplasm C. Chlroplasts D. Nucleus 24. Which of the following monosaccharides is not an aldose? A. Galactose B. Glucose

C. Fructose D. Ribose 25. Which of the following is an epimeric pair? A. D-glucose and D-glucosamine B. D-glucose and D-mannose

C. D-lactose and D-sucrose D. L- mannose and L- fructose 26. When the linear form of glucose cyclizes, the product is a(n): A. Anhydride B. Glcyoside

C. Hemiacetal D. Lactone 27. Which of the following is not a reducing sugar? A. Fructose B. Glucose C. Glyceraldehyde D. Sucrose 28. Which of the following amino acid has amide group in its side chain ? A. cysteine B. Lysine C. Glutamine D. Isoleucine 29. Which of the following amino acid is a alpha helix terminator? A. Tryptophan B. Phenyl alanine C. tyrosine D. Proline 30. The naturally occurring form of amino acid in proteins A. L – amino acids only B. D – amino acids only C. Both L and D amino acids D. None of these

IMMUNOLOGY AND MEDICAL BIOTECHNOLOGY 1. The molecule or substance which induces detectable immune response (humoral / cellular mediated immune response) is called as A. Antibody

B. Immunogen C. MHC D. Antigen 2. Which among the following is called as C5 convertase in classical pathway? A. C3bBb B. C4b2b C. C3bBb3b

D. C4b2a3b 3. A patient is suffering from the defect in thymic development resulted from a presumed failure of the neural crest mesenchyma to induce morphogenetic changes in the third pharyngeal pouch derived endoderm. The patient is suffering from which among the following immunological disease?

A. DiGeorge syndrome B. Grave’s disease C. X-gammaglobulinemia D. Mysthenia Gravis 4. The smallest portion of antigen which act as immunogen is called as A. Paratope B. Allotope

C. Epitope D. Isotope 5. Which among the following is called as secretory antibody? A. IgG

B. IgA C. IgD D. IgM 6. If a particulate antigen reacts with soluble antibody leads to _______ reaction. A. Precipitation B. Neutralization

C. Agglutination D. Flocculation 7. Who among the following discovered the human blood group systems? A. Alexis Carrel

B. Karl Landsteiner C. Jules Bordet D. Robert Koch

8. The strength of the total non-covalent interactions between a single antigen binding site on an antibody is called as A. Valency

B. Affinity C. Avidity D. Cross reactivity 9. Two separate arcs crossing each toher when dissimilar antigen are reacting with antibody by double diffusion method or experiment is A. Identity B. Partial identity

C. Non – identity D. None of the above 10. An enzyme conjugated with an antibody reacts with a colourless substrate to generate a coloured reaction is the basic principle lies behind ____.

A. ELISA B. RIA C. ODD D. RIE 11. The target organ that affected in Mysthenia Gravis is A. Thyroid B. Skin C. Kidney

D. Muscle 12. The immunological reaction, which is mediated by the formation of soluble immune complexes and subsequent activation of complements on the cellular matrix is grouped as A. Type I hypersensitivity reactions B. Type II hypersensitivity reactions C. Type III hypersensitivity reactions D. Type IV hypersensitivity reactions 13. Epstein Barr Virus (EBV), Human papilloma Virus (HPV) are very important virus in the development of

A. Cancers or tumors B. Tolerance to immune system C. Immuno-resistance D. Autoimmune diseases 14.