Analytical Techniques in Biochemistry – A key topic in GAMSAT Biology

Logical reasoning in Physical and Biological Sciences constitutes GAMSAT section III. The primary objective of ACER in creating this section of GAMSAT is to test the logical ability of GAMSAT aspirants in Basic Sciences. Though the multiple choice questions (MCQs) are supported by a background passage and the questions are designed specifically to test the logical reasoning ability of the candidates rather than their background concept, still a basic understanding of the concerned topic is highly appreciated. A clear concept acts as a vital tool for time-management during GAMSAT as it is a time-bound examination. Now, out of the numerous topics covered in GAMSAT Biology, Analytical techniques in Biochemistry can be regarded as a highly important one. The logical justification behind this conclusion is discussed in details in the following paragraphs.

Let us consider an example from GAMSAT practice questionnaire.

Which of the following steps is not an integral part of PCR?

(A) RNA isolation

(B) cDNA synthesis

(C) cDNA amplification

(D) Both A and B

Now, a candidate without any basic understanding on PCR or DNA will consume much more time in getting to the right alternative than a candidate with some basic understanding on DNA and PCR. The candidate, who lacks the basic concepts, will have to collate each and every step of the flow chart and will spend considerable amount of time in doing so. As we have discussed in the beginning that GAMSAT is a time-bound exam, so every single minute counts as a decisive factor. Therefore, to minimise the time-loss we need to acquire all the legitimate tools for answering the questions while spending minimum time. Now, let’s concentrate on the question again equipped with a basic understanding in PCR. The logical way of finding the correct alternative, in this case, is –

PCR or polymerase chain reaction involves the amplification of a target DNA sequence in many folds. Again, cDNA is the complementary DNA produced from a RNA sequence by the action of a reverse transcriptase. Therefore, cDNA can be amplified by PCR technique. But the corresponding RNA molecule and its transformation into cDNA by reverse transcriptase enzyme is an additional portion which is associated with the PCR technique during RT-PCR. Hence option D is most appropriate.

It is evident from the above discussion that a background concept in PCR has helped in deducing the situation, relatively quicker than without any concept. A candidate without background understanding would stumble with the relation between PCR and DNA or cDNA and RNA. Similarly, there are other techniques in this topic which are often exploited by ACER for creating Section III questions, like – Chromatography, ELISA, Tissue culture, etc. Hence, a GAMSAT aspirant should develop at least some basic understanding in these techniques from any standard, reputed source like online tutorials by various educational organisations.