Final answer:
During translation, the ribosome can pause at certain points in the translation of genes. In eukaryotic cells, the ribosome recognizes the 7-methylguanosine cap and searches for the start codon. Kozak's rules indicate which AUG is the correct start codon.
Step-by-step explanation:
In translation, there are genes that are structured so that the ribosome pauses at a certain point in the translation of their mRNAs. In eukaryotic cells, the ribosome recognizes the 7-methylguanosine cap at the 5' end of the mRNA and tracks along the mRNA in the 5' to 3' direction, searching for the AUG start codon. According to Kozak's rules, the nucleotides around the AUG indicate whether it is the correct start codon.