Chapter 2, Problem 5CT

Summary Introduction

To answer:

The amino acids synthesized in a test tube, D and L forms, occur in equal amounts. The cells use only L forms in their proteins. The meteorites are found to contain amino acids, occasionally. Based on these facts, how can the NASA scientists determine whether the amino acids recovered from space are evidence of Earth-like extraterrestrial life rather than the result of non-metabolic processes?

Introduction:

Amino acids exist in nature in L and D forms, but the L-amino acids are predominately found in all cells. The bacterial cell wall only produces D-amino acids.