Question

Arrange the following substrates of the glycolysis pathway in a chronological order of their occurrence in the pathway, starting from Glucose.
A. Fructose-6-phosphate
B. Pyruvic acid
C. Glucose-6-phosphate
D. 2- Phosphoglycerate
Choose the correct answer from the options given below:

• A. B, A, D, C
• B. C, A, D, B
• C. A, D, B, C
• D. D, B, C, A

Hint:

For pathway questions, identify the starting and ending points first. Here, Glucose-6-phosphate (C) is the first intermediate after glucose, and Pyruvic acid (B) is the final product. This immediately points to an answer that starts with C and ends with B, quickly narrowing down the choices.

Answer 1

The Correct Option is B

Step 1: Concept Overview:
The question asks us to order the provided intermediates according to their appearance in the glycolysis pathway, the metabolic process that breaks down glucose into pyruvate.
Step 2: Detailed Solution:
Let's follow glycolysis from glucose:

First, glucose is phosphorylated, yielding Glucose-6-phosphate (C).

Next, Glucose-6-phosphate is isomerized to Fructose-6-phosphate (A).

Fructose-6-phosphate undergoes further phosphorylation and cleavage, leading to the formation of 2-Phosphoglycerate (D) in a later step.

2-Phosphoglycerate is then converted to phosphoenolpyruvate, which is subsequently converted to Pyruvic acid (B), the final product of glycolysis.

Therefore, the sequence of the given substrates is: C \(\rightarrow\) A \(\rightarrow\) D \(\rightarrow\) B.
Step 3: Final Conclusion:
The correct order is Glucose-6-phosphate (C), followed by Fructose-6-phosphate (A), then 2-Phosphoglycerate (D), and finally Pyruvic acid (B). This corresponds to option C, A, D, B.