Exam Questions

Question 1

Describe how a peptide bond is formed between 2 amino acids to form a dipeptide

Answer 1

• Water is removed through a condensation reaction
• the -OH is taken from the carboxyl group of one amino acid and a -H from the amino group from another
• these join to form a peptide bond

Question 2

The secondary structure of a polypeptide is produced by bonds between amino acids. Describe how.

Answer 2

• The H from the amino group has a +ve charge and is attracted to the -ve O from the carboxyl group
• this causes hydrogen bonds to form which causes it to form either a spiral (a-helix) or a B pleated sheet

Question 3

Two proteins have the same number and type of amino acids but different tertiary structures. Explain why.

Answer 3

Because they have a different sequence of amino acids which creates different disulfide, hydrogen and ionic bonds in different places