Quick revision: every question with its correct answer. For the full explanation, open the relevant test and tap View Solution.
3.3 Fibrous & Functional Proteins β Test 1
Q1. The irons in haemoglobin and in the cytochrome of cytochrome oxidase, under normal physiological conditions, differ by their:β Oxidation state
Q2. In haemoglobin, the transition from the T state to the R state (low to high affinity) is triggered by:β Oxygen binding
Q3. Haemoglobin has the highest binding affinity towards:β CO
Q4. Which statements are true for fetal haemoglobin (HbF)?β HbF has higher Oβ affinity than maternal blood and binds BPG weakly
Q5. What explains the transfer of oxygen from adult to fetal haemoglobin?β HbF has higher Oβ affinity because it binds BPG less efficiently than HbA
Q6. Which statements are true for fetal haemoglobin (HbF)?β Higher Oβ affinity than maternal blood; Ξ±βΞ³β; low BPG affinity
Q7. Fetal haemoglobin contains:β 2 Ξ± and 2 Ξ³ subunits
Q8. Which statement is TRUE for hemerythrin?β It has no heme; iron binds directly to the protein
Q9. The porphyrin ring (tetrapyrrole) is NOT found in which functional pigment?β Hemocyanin
Q10. A sigmoid-shaped Oβ-binding curve arises from cooperative binding with:β Haemoglobin
Q11. Adult haemoglobin A consists of:β Two Ξ² chains and two Ξ± chains
Q12. Which statements concerning haemoglobin are TRUE? (1) Sickle-cell anaemia arises from mutated haemoglobin (2) Each subunit has a heme group (3) The mutation can be advantageous against malariaβ 1, 2 and 3
Q13. In addition to Oβ and COβ, haemoglobin also transports:β Nitric oxide
Q14. Which statement is NOT true regarding the haemoglobin molecule?β Enzymes are required to form oxyhaemoglobin
Q15. Binding of oxygen to myoglobin is best described graphically as:β Hyperbolic
Q16. Human and whale muscle myoglobin contents are 8 and 80 g/kg. If 4.49Γ10β»β΄ mol Oβ binds per kg of human myoglobin, the Oβ bound per kg of whale myoglobin is:β 4.49Γ10β»β΄ mol
Q17. Which one is the odd one out with reference to oxygen handling?β Globulin
Q18. In myoglobin, the relationship between Oβ concentration and fraction of sites occupied is best described as:β Hyperbolic
Q19. The heptad repeat of a coiled-coil protein is an imperfect repeat of a sequence of:β 7 amino acids
Q20. The main structural protein of skin and connective tissue, used purified in cosmetic surgery, is:β Collagen
Q21. The major class of insoluble fibrous protein in the extracellular matrix and connective tissue is:β Collagen
Q22. 4-Hydroxyproline is characteristically present in:β Collagen
3.3 Fibrous & Functional Proteins β Test 2
Q23. The amino acid most abundantly found in collagen is:β Glycine
Q24. Which statement regarding collagen is true?β A protein with a short stretch of Gly-X-Y repeats is technically collagenous
Q25. In the collagen triple-helix Gly-X-Y repeat, the residue required at every third position is:β Glycine
Q26. Collagen is best described as a:β Right-handed bundle of three left-handed helices
Q27. Collagen has a:β Triple helical structure
Q28. The highest concentration of cystine is found in:β Keratin
Q29. A fibrous protein can be distinguished from a globular protein of the same mass by:β Size-exclusion chromatography
Q30. Which of the following is considered a fibrous protein?β Keratin
Q31. Human hair and rhino horn are both Ξ±-keratin, but the horn's extra strength is due to more:β Disulphide bonds
Q32. A single myoglobin polypeptide chain contains approximately how many amino acids?β 153
Q33. The whole three-dimensional structure of myoglobin is an example of:β Tertiary structure
Q34. Silk fibroin displays predominantly which structure?β Antiparallel Ξ²-sheet
Q35. The insoluble protein fraction of silk is:β Fibroin
Q36. Regarding the zinc-finger motif, which statements are true? II. It is ~23β30 amino acids long; III. Such proteins act as DNA-binding proteinsβ II and III
Q37. In zinc-finger proteins, the amino acids that coordinate zinc are:β Cys and His
Q38. Haemoglobin has maximum affinity for:β Carbon monoxide
Q39. In hilly areas, the efficiency of Oβ delivery where lung POβ = 50 torr and tissue POβ = 25 torr is closest to:β 0.40
Q40. Match the protein with its function:β i-3, ii-1, iii-2, iv-4
Q41. Match each protein to its function:β i-transport, ii-defence, iii-structure, iv-catalysis
Q42. Which moiety of haemoglobin binds 2,3-bisphosphoglycerate (BPG) at pH 7.0?β Amino terminal
Q43. A respiratory pigment that does NOT use iron as its oxygen-binding site is:β Hemocyanin