In eukaryote genes, nucleotide segments that code for proteins, called , are interrupted by noncoding segments, called . 2. the process by which information encoded in messenger rna (mrna) is used to assemble a protein is called . 3. the enzyme synthesizes an rna strand by first unwinding a dna molecule and then stringing together a series of rna nucleotides complementary to it. 4. a(n) is a sequence of three bases on a molecule of transfer rna (trna) that is complementary to a coding triplet of messenger rna (mrna) bases. 5. amino acids are added one at a time to the growing protein chain, or , on a ribosome. 6. the process by which the genetic information encoded in dna is copied into messenger rna (mrna) is called .