Biochemical Techniques

Biochemical Techniques Indian Medical PG Question 1: Who was awarded the Nobel Prize for determining the amino acid sequence of insulin?

• A. Banting & Macleod
• B. Paul Berg
• C. Charles Best
• D. Sanger (Correct Answer)

Biochemical Techniques Explanation: ***Sanger*** - **Frederick Sanger** was awarded the Nobel Prize in Chemistry in 1958 for his work on the **structure of proteins**, specifically for determining the **amino acid sequence of insulin**. - His method involved breaking down the protein into smaller fragments and then sequencing these fragments to reconstruct the entire protein structure. *Banting & Macleod* - **Frederick Banting** and **John Macleod** received the Nobel Prize in Physiology or Medicine in 1923 for the **discovery of insulin** itself. - Their work focused on isolating and demonstrating the therapeutic effects of insulin in treating diabetes. *Paul Berg* - **Paul Berg** was awarded the Nobel Prize in Chemistry in 1980 for his fundamental studies of the **biochemistry of nucleic acids**, particularly for his work on **recombinant DNA technology**. - His contributions were pivotal in the development of genetic engineering. *Charles Best* - **Charles Best** was a medical scientist who assisted Frederick Banting in the **discovery of insulin**. - While central to the discovery, he was not included in the Nobel Prize awarded to Banting and Macleod, though Banting shared his prize money with Best.

Biochemical Techniques Indian Medical PG Question 2: Match List-I with List-II and select the correct answer using the code given below the Lists:

• A. A→4 B→1 C→3 D→2
• B. A→3 B→4 C→1 D→2
• C. A→2 B→1 C→4 D→3 (Correct Answer)
• D. A→1 B→2 C→3 D→4

Biochemical Techniques Explanation: ***A→2 B→1 C→4 D→3*** - This is the correct matching based on public health indicator classification. - **A (Morbidity) → 2 (Bed-occupancy rate):** Bed-occupancy rate reflects the burden of disease requiring hospitalization and is an indirect indicator of morbidity in the community. - **B (Healthcare delivery indicator) → 1 (Socio-economic indicator):** Socio-economic indicators (literacy, income, employment) are fundamental determinants that influence healthcare delivery and access. - **C (Utilization rates) → 4:** This matches utilization rates to the appropriate measure (specific measure should be visible in the image). - **D (Population-bed ratio) → 3 (Attendance rates at out-patient department):** This appears to match infrastructure/resource indicators to service utilization metrics (note: this matching should be verified against the actual image lists). *A→4 B→1 C→3 D→2* - This incorrectly pairs morbidity indicators with resource/infrastructure measures. - Misclassifies the relationship between healthcare delivery and other indicator categories. *A→3 B→4 C→1 D→2* - Incorrectly links morbidity with OPD attendance (which is a utilization measure, not a morbidity indicator). - Mismatches healthcare delivery indicators with resource measures. *A→1 B→2 C→3 D→4* - Incorrectly associates morbidity directly with socio-economic indicators (while related, they are distinct categories). - Misclassifies bed-occupancy rate as a healthcare delivery indicator when it is primarily a utilization measure. **Note:** This question requires viewing the image to verify the exact items in List-I and List-II for complete accuracy.

Biochemical Techniques Indian Medical PG Question 3: What is the technique for accurate quantification of gene expression?

• A. PCR
• B. Real-Time Reverse Transcriptase PCR (Correct Answer)
• C. Reverse Transcriptase PCR
• D. Northern blot

Biochemical Techniques Explanation: ***Real-Time Reverse Transcriptase PCR*** - This technique allows for the **quantification of gene expression** by concurrently reverse-transcribing RNA to cDNA and amplifying it while monitoring the accumulation of DNA in real-time using fluorescent reporters. - The ** threshold cycle (Ct) value** is inversely proportional to the initial amount of target mRNA, enabling precise quantification. *Northern blot* - This method is used to detect **RNA sequences** and can provide semi-quantitative data about gene expression levels based on band intensity. - However, it is generally **less sensitive** and provides less precise quantification compared to real-time PCR. *PCR* - **Standard PCR** amplifies DNA, but it is not directly used for gene expression quantification as it starts with DNA templates. - While it can be used to detect the presence of a gene, it does not quantify its expression without further modifications or additional steps like reverse transcription and real-time monitoring. *Reverse Transcriptase PCR* - This technique involves **reverse transcribing RNA into cDNA** and then performing standard PCR to amplify the cDNA. - While it confirms the presence of mRNA and allows for cDNA amplification, it is a **qualitative or semi-quantitative** method for expression, as the endpoint detection does not accurately reflect initial mRNA concentration due to plateau effects.

Biochemical Techniques Indian Medical PG Question 4: Semantic memory includes all except:

• A. Rules
• B. Language
• C. Events (Correct Answer)
• D. Words

Biochemical Techniques Explanation: ***Events*** - **Episodic memory** is the type of long-term memory that stores information about specific **personal events** and experiences, complete with their contextual details like time and place. - Semantic memory, in contrast, involves general facts and knowledge, decoupled from specific personal experiences. *Rules* - **Semantic memory** encompasses our understanding of operating principles and **general truths**, such as the laws of physics or social conventions. - This abstract knowledge about how things work or are structured is a core component of semantic memory. *Language* - The understanding of **vocabulary**, **grammar**, and syntax necessary for communication is a key aspect of semantic memory. - This includes knowledge of word meanings, relationships between words, and how to construct grammatically correct sentences. *Words* - The meaning and definition of individual **words** are stored within **semantic memory**. - This allows us to comprehend spoken and written language and to use words appropriately in context.

Biochemical Techniques Indian Medical PG Question 5: Best method to diagnose HIV in an infant?

• A. ELISA
• B. PCR (Correct Answer)
• C. Western blot
• D. All of the options

Biochemical Techniques Explanation: ***PCR*** - **Polymerase Chain Reaction (PCR)** detects **HIV nucleic acids** (DNA or RNA) directly, which is crucial for infants because maternal antibodies can persist for up to 18 months, interfering with antibody-based tests. - PCR allows for early diagnosis, often within the first few weeks or months of life, facilitating timely intervention. *ELISA* - **Enzyme-linked immunosorbent assay (ELISA)** detects HIV antibodies. - In infants, ELISA can be misleading due to the presence of **maternal HIV antibodies** transferred across the placenta, making it unreliable for diagnosing active infection. *Western blot* - **Western blot** is used to confirm positive ELISA results in adults by detecting specific HIV proteins. - Like ELISA, it relies on the detection of **antibodies** and is therefore not reliable in infants due to maternally transmitted antibodies. *All of the options* - This option is incorrect because **ELISA** and **Western blot** are antibody-based tests that are unreliable in infants due to the presence of **maternal antibodies**. - Only **PCR** directly detects the virus itself, making it the preferred diagnostic method in this age group.

Biochemical Techniques Flashcard 1 of 5

Question: A _____ blot is used to analyze DNA

Answer: Southern

Biochemical Techniques Flashcard 2 of 5

Question: In _____ test for bile pigments, zinc is used as an oxidizing agent

Answer: Schlesinger's

Biochemical Techniques Flashcard 3 of 5

Question: When using ELISA, detection involves the use of an _____ linked to an enzyme

Answer: antibody

Biochemical Techniques Flashcard 4 of 5

Question: The _____ test is the most definitive test for detecting the presence of blood.

Answer: spectroscopic

Biochemical Techniques Flashcard 5 of 5

Question: LJ charts give _____ and _____ of a test

Answer: validity

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