---
title: "Protein Synthesis Simulator — DNA → mRNA → Protein"
description: "Simulate transcription and translation: DNA to mRNA to amino acids, with codon table, start/stop, and frameshift mutations. Rigorous, free educational tool."
url: "https://worldcalculators.org/calculators/protein-synthesis/"
canonical: "https://worldcalculators.org/calculators/protein-synthesis/"
---

# Protein Synthesis Simulator

Simulate transcription and translation: DNA to mRNA to amino acids, with codon table, start/stop, and frameshift mutations. Rigorous, free educational tool.

## Quick answer

Coding strand matches the mRNA (T→U). Type it 5'→3'.

## Transcription, translation, and why sequence order matters

Both stages build their product 5'→3' : RNA polymerase adds nucleotides to the 3' end of the growing mRNA, and the ribosome reads the mRNA from its 5' end toward 3'. That's why this simulator asks which strand you typed and in which direction — flipping a sequence or swapping strands changes the protein entirely.
The genetic code is degenerate: 64 codons, 20 amino acids. Most of the redundancy lives at the third codon position, where tRNA anticodons tolerate non-standard "wobble" pairing. Leucine and serine have six codons each; methionine and tryptophan have exactly one. This is evolution's error buffer — many third-position point mutations are silent , leaving the protein unchanged.

## Frequently Asked Questions

Information flows DNA → RNA → protein. Transcription makes RNA from a DNA template; translation makes protein from the mRNA. Reverse transcription exists in retroviruses but is an exception.
UAA, UAG, and UGA. They don't encode amino acids; release factors terminate the chain. AUG is the start codon and encodes methionine.

## Sources & Methodology

Transcription converts the entered strand to mRNA (coding: T→U; template: complement with U). Translation scans for the first AUG, maps each in-frame codon via the standard genetic code, and stops at the first UAA, UAG, or UGA.

Source: https://worldcalculators.org/calculators/protein-synthesis/
Markdown mirror of the HTML page. Prefer this URL for RAG; the interactive calculator still lives on the HTML page.