2024 RI H2 Bio P2 MS

© RI 2024 Preliminary Examination 9744/02 [Turn over RAFFLES INSTITUTION 2024 Year 6 Preliminary Examination Higher 2 BIOLOGY 9744/02 Paper 2 Structured Questions 18th September 2024 2 hours Candidates answer on Question Paper. No Additional Materials are required. READ THESE INSTRUCTIONS FIRST Write your index number, CT group & name in the spaces at the top of this page. Write in a dark blue or black pen. You may use a HB pencil for any diagrams or graphs. Do not use staples, paper clips, glue or correction fluid. Answer all questions in the spaces provided on the Question Paper. The use of an approved scientific calculator is expected, where appropriate. You may lose marks if you do not show your working or if you do not use appropriate units At the end of the examination, fasten all your work securely together. The number of marks is given in brackets [ ] at the end of each question or part question. This document consists of 25 printed pages. CIVICS GROUP CANDIDATE NAME INDEX NUMBER 4 S 0 3 2 For Examiner’s Use 1 / 9 2 / 10 3 / 10 4 / 10 5 / 10 6 / 11 7 / 10 8 / 10 9 / 10 10 / 5 11 / 5 Total / 100 Raffles Institution Internal Examination

2 © RI 2024 Preliminary Examination 9744/02 For Examiner’s Use [Turn over Section A Answer all the questions in this section. 1 Fig. 1.1 shows the structure of pancreatic ribonuclease (RNase A) which hydrolyses RNA. Fig. 1.1 (a) (i) Describe two features of RNase A that make it a globular protein. [2] 1. It has a spherical shape / de scription of secondary structures further fold to form a compact shape; (Reject: globular) 2. It has amino acid sequences t hat are irregular/unique/not repetitive; 3. It serves a metabolic role as an enzyme* in hydrolysing RNA; (No need to mark for metabolic role) 4. It is soluble in water; (Mark er to accept: hydrophilic R groups on the outside and hydrophobic R groups on the inside) (ii) With reference to Fig. 1.1, describe two structural differences between RNase A and haemoglobin. [2] feature RNAse A haemo globin 1. Level of protein folding OR Number of polypeptide/ subunit Tertiary structure One Quaternary structure Four 2. Presence of haem* group No Yes 3. Type of site for binding to specific biomolecule Active site* for RNA (phosphodiester bonds) Binding sites for oxygen (Marker to decide if he/she will accept no active site ) 4. Beta-pleated sheet Present Absent N-terminus C-terminus

3 © RI 2024 Preliminary Examination 9744/02 [Turn over For Examiner’s Use (b) Christian Anfi