Compare6 marksChallenge
A researcher studies two proteins from a species of Antarctic fish. Protein X is found in the blood and transports oxygen. Protein Y forms long fibres in the skin, providing tensile strength. The table shows some characteristics of each protein.
| Feature | Protein X | Protein Y |
|---|---|---|
| Solubility in water | High | Very low |
| Number of polypeptide chains | 4 | 3 |
| Presence of disulfide bonds | Yes, between chains | Yes, within and between chains |
| Secondary structure | Mainly alpha-helices | Repeating glycine-rich sequence allowing tight coiling |
| Prosthetic group | Haem group containing iron | None |
| Overall shape | Roughly spherical | Long, rod-like |
Compare the structure and function of Protein X and Protein Y. In your answer, refer to:
- the four levels of protein structure (primary, secondary, tertiary, quaternary)
- the types of bonds and interactions that stabilize each protein
- how their structures relate to their functions