Model DNA to Protein
Build a protein from DNA: copy the template strand into mRNA (T to U), then read codons to name the amino acids.
- DNA/RNA base pairing: Building mRNA means pairing each DNA base to its partner (A-U, T-A, C-G, G-C).
- Use a codon chart: Naming the amino acid means looking up each three-base codon on a chart.
Prerequisites are inferred: pending teacher review.
Re-learn the skill with worked practice and clear examples.
Model DNA to protein in two steps: transcribe the template strand into mRNA (T to U), then translate the mRNA codon into its amino acid using the chart.
A DNA template strand reads TAC. Build the mRNA (pair each base, T becomes U) and use the chart to name the amino acid.
Approved| DNA base on template | mRNA base to write |
|---|---|
| A | U |
| T | A |
| C | G |
| G | C |
| mRNA codon | Amino acid |
| AUG | Methionine (Met) - start |
| UUU | Phenylalanine (Phe) |
| UAC | Tyrosine (Tyr) |
| GGU | Glycine (Gly) |
- A.mRNA AUG = Methionine (Met)
- B.mRNA UUU = Phenylalanine (Phe)
- C.mRNA TAC = Tyrosine (Tyr)
- D.mRNA GGU = Glycine (Gly)
Show the worked solution ▾
Answer: A. mRNA AUG = Methionine (Met)
- Step 1: Pair each base: T->A, A->U, C->G using the pairing table, so DNA TAC gives mRNA AUG.
- Step 2: Look up the codon: The chart shows AUG codes for Methionine (Met), the start amino acid.
Why it's right: DNA template TAC pairs to mRNA AUG (T->A, A->U, C->G), and the chart shows AUG = Methionine.
- B: UUU comes from DNA AAA, not from TAC.
- C: mRNA uses U, not T, so the mRNA is AUG, not TAC.
- D: GGU comes from DNA CCA, not from TAC.
Aligned to Biotechnology Research and Experiments: transcribe and translate · reading level ~grade 9
A DNA template strand reads CCA. Pair each base into mRNA, then choose the line that names the codon you built and the amino acid it calls for.
Reviewed- A.mRNA CCA, which calls for proline
- B.mRNA UUA, which calls for leucine
- C.mRNA GGU, which calls for glycine
- D.mRNA GGT, which calls for glycine
Show the worked solution ▾
Answer: C. mRNA GGU, which calls for glycine
- Step 1: Pair each base: Template C pairs with G, the second C pairs with G, and template A pairs with U.
- Step 2: Read the codon: That gives the mRNA codon GGU.
- Step 3: Look it up: GGU calls for glycine.
Why it's right: Template C gives G, C gives G, and A gives U, so the mRNA codon is GGU, and GGU calls for glycine.
- A: This copies the DNA letters instead of pairing them. CCA really does call for proline, but that is not what this template produces.
- B: This pairs the bases wrongly. Template C gives G, not U.
- D: RNA never uses T. The pairing is right, but the last base has to be written as U.
Aligned to Biotechnology Research and Experiments · reading level ~grade 9
- In Unit 2.2 Decoding a Diagnosis, this skill turns class evidence into a result another person can check.
Fill these in as you work through the lesson.
- Template strand (the DNA side that is copied):
- Transcription (DNA -> mRNA):
- mRNA (the message copy of the gene):
- Codon (three mRNA bases = one amino acid):
- Translation (mRNA codons -> amino acids):
- Amino acid (a protein building block):
To copy DNA into mRNA, pair A with , T with , C with , and G with . Then read the mRNA in groups of bases to name each amino acid.
- When you build mRNA from DNA, which base replaces T?
- How many mRNA bases make one codon?
- What two steps take you from a DNA template strand to a finished chain of amino acids?
DNA template = TAC. Build the mRNA (pair each base, T->U) and then name the amino acid. (Answer: mRNA = AUG, which the chart shows is Methionine, the start.)