International A Level Biology / Proteins and DNA

The genetic code

Edexcel International A Level Biology (YBI11), chapter 5: Proteins and DNA, specification point 2.11, 2.12. Part of the full course.

Read the revision notes · International A Level Biology past papers

The genetic code is the set of rules that links DNA base sequences to the amino acid sequence of a polypeptide. Its triplet, non-overlapping and degenerate features explain how it codes for amino acids and controls where translation starts and ends.

More lessons in Proteins and DNA

• Enzymes: biological catalysts
• Active sites, specificity and induced fit
• Core practical 4: measuring the initial rate of an enzyme reaction
• Temperature, pH, enzyme and substrate concentration
• Nucleotides, DNA and RNA
• Semi-conservative DNA replication
• Meselson and Stahl: proving semi-conservative replication
• Transcription: DNA to mRNA
• Translation: mRNA to polypeptide