Protein Synthesis

NCEA Level 2 Biology Gene Expression

1. Transcription (in nucleus)

RNA polymerase reads specific gene on DNA (template strand/antisense strand).

2. Transcription (in nucleus)

RNA polymerase makes mRNA that complements DNA sequence ‘read’ in step 1.

3. Transcription (in nucleus)

mRNA moves out of cell nucleus through nuclear pores.

4. Translation (in cytoplasm)

mRNA attaches to ribosome, which reads genetic code in sets of three bases (codons).

5. Translation (in cytoplasm)

tRNA match their anticodons to mRNA codons and deliver amino acid with tRNA.

6. Translation (in cytoplasm)

Ribosomes join amino acids together with peptide bonds to form growing peptide chain until stop codon ends process.

7. Translation (in cytoplasm)

Final chain folds into functional 3D protein.

rRNA

forms structure of ribosomes.