# A research team is studying how muscle cells in an athlete produce large amounts of myosin, a structural protein needed for muscle contraction. Describe how the genetic information in a cell leads to the production of myosin, starting from the DNA in the nucleus.

> OCR A-Level Biology B — Advancing Biology (H422) — 5.1 Genetic control of protein synthesis · Describe · 5 marks

> Myosin is a protein made up of a specific sequence of amino acids. It is encoded by a gene found on one of the chromosomes inside muscle cell nuclei.

## Mark scheme (5 marks)

1. A gene is a section of DNA that codes for a specific amino acid sequence / the myosin gene codes for the specific amino acid sequence of myosin
2. The DNA / gene is transcribed and a copy is made as mRNA (messenger RNA) in the nucleus
3. The mRNA carries the genetic information from the nucleus to the ribosomes
4. At the ribosome, the mRNA sequence is translated into an amino acid sequence
5. The amino acids are joined together in a specific sequence to form the protein myosin / the specific sequence of amino acids determines the structure and function of the protein

## Key terms

- [gene](https://www.gradenine.co.uk/glossary/gene)

## Related

- [Revision notes for OCR A-Level Biology B — Advancing Biology (H422)](https://www.gradenine.co.uk/learn)
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Source: [GradeNine](https://www.gradenine.co.uk/q/a-research-team-is-studying-how-8abae87a) · Published by Druglandscape Ltd.