Bio Engineering interview questions and answers - part 4

Part 1   Part 2   Part 3   Part 4   Part 5   Part 6 What are immunoglobulins? Explain its structure. Immunoglobulins are popularly known as antibody. These are large Y-shaped protein produced by B-cells that is used by the immune system to identify and neutralize foreign objects such as bacteria and viruses. Immunoglobulins are "Y" shaped structure which is having two tips and each tip of immunoglobulins contains a paratope. Immunoglobulins are typically made of basic structural units—each with two large heavy chains and two small light chains. The general structure of all antibodies is very similar; a small region at the tip of the protein is extremely variable. Explain superiority of TLC over paper chromatography. TLC is superior over paper chromatography because of inorganic nature of adsorbent concentrated sulfuric acid spray. The spray is then followed by heating. It may be used to develop on the chromatogram by charring. Also, amino acid mixtures require 18 hours for separation on paper. It requires 3 hrs using cellulose TLC. The advantages of TLC lie in adsorbents which don’t allow separation on paper. In TLC we have much wider choice of adsorbents depending upon needs and sample. Explain is isotopic tracer technique? This technique is used to understand chemical reaction and interactions in bio-chemistry and chemistry. In this technique, one or more of the atoms of the molecule of interest is substituted for an atom of the same chemical element, but that element belongs to different isotope. It can be used to detect the difference in number of neutrons separately from the other atoms of the same element. The atom has the same number of protons; it will behave in almost exactly the same way chemically as other atoms in the compound, and with few exceptions will not interfere with the reaction under investigation. Explain the technique of gene conversion. Gene conversion refers to the event in DNA genetic recombination. This event occurs at high frequencies during meiotic division but which also occurs in somatic cells. Through this process we can transfer DNA information from one DNA helix to another DNA helix, whose sequence is altered. Gene mutation can also be accomplished through this process. IT may lead to non-Mendelian inheritance. This phenomenon has often been recorded in fungal crosses. Differentiate between introns and exons. An intron refers to any nucleotide sequence within a gene which is removed by RNA splicing to generate the final mature RNA product of a gene. The term intron refers to both the DNA sequence within a gene, and the corresponding sequence in RNA transcripts. Introns are found in the genes of most organisms and many viruses. An exon can be referred to a sequence in DNA or its RNA transcript. In broad sense. An exon is a nucleic acid sequence that is represented in the mature form of an RNA molecule. Part 1   Part 2   Part 3   Part 4   Part 5   Part 6 Write your comment - Share Knowledge and Experience