The Protein Synthesis Studio

The Protein Synthesis Studio 🧬

Your DNA is a set of instructions — but instructions for what? For building **proteins**: the enzymes, hormones and structures that run your body. This module (Higher tier) follows the code from gene to finished protein through two stages: **transcription** and **translation**.

The code in the bases 🔤

A **gene** is a length of DNA. The **order of its bases** sets the **order of amino acids** in a protein. That amino-acid order decides how the chain **folds** into a particular 3D **shape** — and a protein's shape decides its **function** (like the exact shape of an enzyme's active site).

What does the base order set?

In a gene, what does the order of the bases determine?

• The order of amino acids in the protein, and so its shape and function
• The colour of the DNA molecule
• How many chromosomes the cell has
• Nothing — the base order is random

Stage 1: transcription ✍️

Protein synthesis has two stages. The first is **transcription**, in the **nucleus**: • The DNA **unwinds** at the gene. • The enzyme **RNA polymerase** builds a strand of **mRNA** with a base sequence **complementary** to the coding DNA strand. • The mRNA then leaves the nucleus and travels to a **ribosome**.

Stage 2: translation 🔨

The second stage is **translation**, at the **ribosome**: • The ribosome reads the mRNA in **codons** — groups of **three bases**. • **tRNA** molecules each bring the **specific amino acid** that matches a codon. • The amino acids are **joined together** into a **polypeptide** chain.

Define a codon

What is a codon?

• A group of three mRNA bases that codes for one amino acid
• A single base of DNA
• The enzyme that builds mRNA
• A whole finished protein

Label translation

An interactive activity.

Match each molecule to its role

The whole pathway

An interactive activity.

True about protein synthesis

Select ALL THREE statements about protein synthesis that are TRUE.

• RNA polymerase builds mRNA during transcription
• A codon is three mRNA bases
• tRNA brings amino acids to the ribosome
• Translation happens inside the nucleus
• mRNA is identical to the coding DNA strand
• One base codes for one amino acid

Folding into shape 🎯

The finished **polypeptide** does not stay as a straight chain. It **folds up** into a specific 3D shape, set by its amino-acid sequence. That shape is what lets the protein do its job — an enzyme's active site, a hormone's precise fit, a structural fibre's strength. Change the base order and you can change the shape, and so the function.

Match each term to its meaning

Where does it happen?

Where do transcription and translation take place?

• Transcription in the nucleus; translation at the ribosome
• Both in the nucleus
• Both at the ribosome
• Transcription at the ribosome; translation in the nucleus

What happens in translation?

Select ALL THREE statements about translation that are TRUE.

• The ribosome reads mRNA in three-base codons
• tRNA carries a specific amino acid for each codon
• Amino acids are joined into a polypeptide chain
• The ribosome unwinds the DNA
• tRNA copies the DNA
• Each codon codes for a whole protein

Studio summary

In transcription, the enzyme RNA _____ builds an mRNA strand complementary to the DNA. The mRNA moves to a _____, where it is read in _____ of three bases. tRNA brings the matching amino acids, which are joined into a _____.