Sickle cell anaemia results from the substitution of a single amino acid in haemoglobin. This fact demonstrates that
- A. a protein's function depends on its precise amino acid sequence
- B. haemoglobin is a fibrous structural protein
- C. every mutation is lethal
- D. haemoglobin normally cannot bind oxygen
Explanation
One change in the primary structure alters haemoglobin's shape so that it polymerises in low oxygen, distorting the red cell. The disease is neither lethal in all carriers nor a sign haemoglobin cannot bind oxygen at all, which shows how sensitively function follows sequence.
Related questions
Which class of organic molecule forms the greatest proportion of the dry mass of a typical cell?
The four elements that together make up about 99 per cent of the mass of living matter are
The monomer unit from which a nucleic acid is built is
The process by which small molecules join together to build a macromolecule, with water released at each link, is called
Which element is always present in proteins but never in simple carbohydrates or triglycerides?