ProteinsEdexcel A-Level Biology B: Mind map

Exam questions on Proteins

1. A biochemist synthesises a short polypeptide in the laboratory by joining amino acids together one at a time. She is checking that the bonds formed are the same as those found in proteins made in cells.
   Explain what is meant by the primary structure of the polypeptide and why a change in the primary structure could change the function of the protein.2 marks
2. Haemoglobin is the protein in red blood cells that carries oxygen. It is soluble in the cytoplasm of the red blood cell and each molecule can carry up to four oxygen molecules.
   Explain why haemoglobin is soluble in the cytoplasm of a red blood cell.2 marks
3. Tendons connect muscle to bone and must resist large pulling forces without stretching. The main protein in a tendon is collagen, which is a fibrous protein, whereas haemoglobin in the blood is a globular protein.
   Explain how the structure of collagen makes it suitable for its role in a tendon.3 marks