2022 EJC Promo JC1 Bio P2 (Q)

©EJC 2022 9744/ J1H2Promotional Examination /2022 [Turn over EUNOIA JUNIOR COLLEGE JC1 Promotional Examination 2022 General Certificate of Education Advanced Level Higher 2 CANDIDATE NAME CIVICS GROUP 2 2 - REGISTRATION NUMBER H2 Biology 9744 / 02 04 October 2022 2 hours Additional Materials: 12-page Answer Booklet. READ THESE INSTRUCTIONS FIRST Write your name, civics group and registration number on all the work you hand in. Write in dark blue or black pen. You may use an HB pencil for any diagrams or graphs. Do not use paper clips, highlighters, glue or correction fluid. Section A Answer all questions in the spaces provided on the Question Paper. Section B Answer all questions in the 12-page Answer Booklet. 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. The number of marks is given in brackets [ ] at the end of each question or part question. At the end of the examination, submit the Question Booklet and the 12-page Answer Booklet separately. This document consists of 19 printed pages and 1 blank page. For Examiner’s Use Section A 1 2 3 4 5 Section B 6 Total 80

2 ©EJC 2022 9744/J1H2Promotional Examination/2022 Section A Answer all questions in the spaces provided. 1 Fig. 1.1 shows the process of collagen synthesis in a fibroblast cell. Fig. 1.1 (a) With reference to Fig. 1.1, describe how procollagen is transported out of the cell. ……………………………………………………………………………………………………………… ……………………………………………………………………………………………………………… ……………………………………………………………………………………………………………… ……………………………………………………………………………………………………………… ……………………………………………………………………………………………………………… …………………………………………………………………………………………………………… [3]

3 ©EJC 2022 9744/ J1H2Promotional Examination /2022 [Turn over (b) The primary structure of a collagen polypeptide has a repeating pattern of three amino acids. Fig. 1.2 shows the two forms of this pattern. Fig. 1.2 Hydroxyproline is a proline molecule that has a hydroxyl ( -OH) group added to its R -group. The hydroxyl groups are involved in hydrogen bonding in tropocollagen. Glycine makes up approximately 30% of the total amino acid composition of collagen. Explain how the structure of glycine plays an essential role in contributing to the high tensile strength of tropocollagen. ……………………………………………………………………………………………………………… ……………………………………………………………………………………………………………… ……………………………………………………………………………………………………………… ……………………………………………………………………………………………………………… ……………………………………………………………………………………………………………… …………………………………………………………………………………………………………… [3]

4 ©EJC 2022 9744/J1H2Promotional Examination/2022 (c) Many of the lysine amino acids in a collagen polypeptide also have a hydroxyl (-OH) group added to their R-