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: Understanding the Concept:
The question requires ordering a given set of intermediates as they appear in the glycolysis pathway, which is the metabolic pathway that converts glucose into pyruvate.
Step 2: Detailed Explanation:
Let's trace the path of glycolysis from glucose:

The first step is the phosphorylation of Glucose to form Glucose-6-phosphate (C).

Glucose-6-phosphate is then isomerized to form Fructose-6-phosphate (A).

Fructose-6-phosphate is further phosphorylated and then cleaved, and after several more steps in the payoff phase, the intermediate 2-Phosphoglycerate (D) is formed.

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

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