The nucleic acid responsible for transporting amino acids to ribosomes during protein synthesis is tRNA (transfer RNA). tRNA molecules have specific anticodons that recognize codons on mRNA, ensuring the correct amino acid is delivered in sequence. This precise matching is critical for accurate protein assembly. Unlike mRNA, which carries the genetic code, or rRNA, which forms the ribosome's core, tRNA functions as the adaptor linking the genetic code to amino acids. This role is essential in translation, directly impacting protein structure and function, which is crucial in clinical scenarios involving genetic or translational defects.

Reference: Molecular Biology of the Cell, Bruce Alberts, 6th Edition.