In nucleic acids, DNA and RNA 5’ end refers to phosphate group attached to the 5′ carbon of the ribose ring, while 3’ end refers to the ribose -OH substituent. Nucleic acids can only be synthesized in the 5′-to-3′ direction, which means that the DNA template is 3’—5’. Translation of the protein by the ribosome will also proceed in a 5′ to 3′ direction, which means that the mRNA template is 3’—5’.
The protein during the synthesis is extend from its N terminus toward its C terminus.