Chapter 18, Problem 14P

Interpretation Introduction

Interpretation:

To predict which carbon and nitrogen atoms of GTP are precursors to $\text{N-1}$, $\text{C-2}$, $\text{C-4}$, $\text{N-5}$, $\text{C-7}$, $\text{N-8}$, $\text{C-9}$ of dihydrofolate.

Concept introduction:

The human beings obtain DHF or dihydrofolate from the diet through the active transport of its precursor folic acid but the bacteria have synthesis mechanism for their dihydrofolate requirements.

The structures of dihydrofolate and GTP are given with carbon and nitrogen atoms numbered in the question, the corresponding figure is: