The codes for proteins, which are contained within DNA, are not directly transported to ribosomes. Instead, a messenger molecule called messenger RNA (mRNA) carries the code from the nucleus to the ribosomes. Here's the breakdown:

1. Transcription: The DNA sequence for a specific protein is transcribed into mRNA within the nucleus. This means that the DNA code is copied into a complementary mRNA molecule.

2. RNA Processing: The newly formed mRNA undergoes some processing steps, including the addition of a cap and tail, which help protect it and ensure its proper translation.

3. Export: The processed mRNA molecule leaves the nucleus through nuclear pores and enters the cytoplasm.

4. Translation: The mRNA travels to a ribosome, where it's translated into a protein. Ribosomes read the mRNA code in groups of three nucleotides called codons. Each codon corresponds to a specific amino acid. The ribosome assembles the amino acids in the order specified by the mRNA, building the protein chain.

In essence: DNA acts as the blueprint, mRNA is the messenger carrying the blueprint instructions, and ribosomes are the construction workers who build the protein based on those instructions.