Biochemistry Basics

Question Which of these is a denaturating substance? A. Guanosine B. Guanidine C. Glutamate D. Glycine   Show Answer Correct Answer » B Explanation Ans.B. Guanidine Guanidine is the denaturation substance. It is used in affinity chromatography.

Question Part of eukaryotic DNA contributing to polypeptide synthesis: A. Exon B. Enhancer C. Leader sequence D. a and b both   Show Answer Correct Answer » D Explanation Most eukaryotic genes have alternating exons and introns. In this example, there are nine exons (blue-colored areas) and eight introns (green-colored areas). The introns are removed

Question Structural proteins are: A. Fibrous B. Globular C. Branched D. Compound   Show Answer Correct Answer » A Explanation Ans ‘A’ Fibrous The molecules are elongated or needle-shaped. Their solubility is minimum. They resist digestion. Collagen, elastin, and keratins are examples.

Question Which of the following are intracellular events occurring in fibroblast during the synthesis of collagen? A. Hydrolysis of procollagen to collagen B. Glycosylation of proline C. Formation of the triple helix D. Formation of covalent cross-link between fibrils   Show Answer Correct Answer » C Explanation Collagen is a triple-helical structure in which 3 A-chains are

Question True about genetic code: A. AUA codes for methionine in mitochondria B. UGA codes for selenocysteine C. AUG codes for initiator codon in mammalian cell and AGA & AGG act as chain terminator in mammalian mitochondria both D. All   Show Answer Correct Answer » D Explanation In mammalian mitochondria, the codon AUA is

Question Albumin and globulin are classified as: A. Conjugated proteins B. Simple globular proteins C. Unconjugated proteins D. Derived proteins   Show Answer Correct Answer » B Explanation Ans ‘B’ Simple globular protein  Plasma proteins like albumin and globulin are simple globular proteins Globular proteins are compact, roughly spherical molecules that have axial ratios (the

Question True about Proto-oncogenes are: A. Normally involved in cell cycle proliferation B. Produces tumor C. Proto-oncogenes on mutation causes cancer. D. A and C both   Show Answer Correct Answer » D Explanation Proto-oncogenes are important regulatory genes of the cells. Exposure of target cells to PDGF can result in rapid (minutes to 1–2

Question In SDS-PAGE (Sodium Dodecyl Sulfate-Polyacrylamide Gel Electrophoresis) proteins are separated on basis of: A. Mass B. Charge C. Density D. None   Show Answer Correct Answer » A Explanation The most widely used method for determining the purity of a protein is SDS-PAGE—polyacrylamide gel electrophoresis (PAGE) in the presence of the anionic detergent sodium

Question 5-methyl cytosine mutation of DNA (DNA methylation) leads to: A. Deamination to thiamine; B. DNA repair C. Methylation protects the host DNA from cleavage by its own restriction enzyme D. All   Show Answer Correct Answer » D Explanation Deamination of cytosine forms uracil and deamination of 5 methylcytosine forms thymine. TDG & MBD4

Question Which statements are true about E. coli chromosomal DNA in relation with eukaryotic chromosomal DNA: A. Circular B. Packed into nucleolus C. Negatively supercoiled D. All of the above   Show Answer Correct Answer » D Explanation Long circular bacterial chromosomal DNA may be folded by an unknown mechanism to form a compact ring