Proteins consist of amino acid monomers joined in chains. The structures of two amino acids, valine and serine, are shown. Draw the dipeptide val-ser, showing the peptide bond in displayed form.
What kind of reaction occurs to form this dipeptide?
Name the additional molecule produced in this reaction.
DNA and RNA are both involved in protein synthesis. Complete the table to show three structural differences between DNA and RNA.
In protein synthesis, portions of DNA are copied into mRNA and this is then read by the ribosome to assemble the amino acids into a new protein chain. Each set of three bases codes for one amino acid, although some amino acids have more than one code. The codes are shown in the table. Use the abbreviations to state the amino acid sequence in the peptide for the base sequence shown, $\text{-AUGCUAACACCGGAGUAA-}$.
What are errors in the base sequence called?
This kind of error can produce a protein with a different structure from the original, as seen in sickle cell anaemia. Here, the amino acid glutamic acid (glu) is replaced by valine (val) in the protein because one base in a three base code has changed. Use the table to suggest the base change that causes this.