2022 EJC Promo JC1 P1 Bio (A)

©EJC 2022 9744/01/J1H2PROMO/2022 [Turn over EUNOIA JUNIOR COLLEGE JC1 Promotional Examinations 2022 General Certificate of Education Advanced Level Higher 2 H2 Biology Paper 1 9744 / 01 04 October 2022 1 hour Additional Materials: Optical Mark Sheet READ THESE INSTRUCTIONS FIRST You have a total of 1 hour to attempt this paper. Write your name, civics group and registration number on all the work you hand in. There are thirty questions. For each question, there are four possible answers A, B, C and D. Choose the one you consider correct and record your choice in soft pencil on the separate Optical Mark Sheet. The use of an approved scientific calculator is expected, where appropriate. Answer all questions. This document consists of 19 printed pages and 1 blank page.

2 ©EJC 2022 9744/01/J1H2PROMO/2022 Answer all questions on the Optical Mark Sheet provided. 1 Dextrins a re a group of carbohydrates with low molecular weight and are produced by hydrolysing starch or glycogen. Which of the following segments is/are not likely to be from a dextrin molecule? 1 2 3 4 A 1 only B 1 and 4 only C 1, 2 and 3 only D 2, 3 and 4 only

3 ©EJC 2022 9744/01/J1H2PROMO/2022 [Turn over 2 The diagram below shows a repeating unit found in a biomolecule. Which of the following biomolecules has the above repeating unit? cellulose glycogen amylose collagen A X X √ X B √ X √ X C √ X X √ D X √ √ X 3 The structure of phosphatidylcholine, a common membrane phospholipid, is shown. Which combination correctly describes the synthesis and property of one molecule of phosphatidylcholine? number of water molecules eliminated during synthesis property A 3 amphipathic B 2 amphipathic C 3 hydrophobic D 2 hydrophobic

4 ©EJC 2022 9744/01/J1H2PROMO/2022 4 A peptide section of an insulin molecule was hydrolysed by two proteases, trypsin and chymotrypsin. • Trypsin breaks the peptide bonds at the carboxyl terminals of lysine (lys) and arginine (arg). • Chymotrypsin breaks the peptide bonds at the carboxyl terminals of phenylalanine (phe), tryptophan (trp) and tyrosine (tyr). The hydrolysis was performed separately using: 1 both enzymes, or 2 trypsin only, or 3 chymotrypsin only. The sequence of amino acid residues in the peptide is shown below: tyr-leu-val-cys-gly-glu-arg-gly-phe-phe-tyr-thr-pro-lys-ala Which statement concerning the products of hydrolysis is correct? A Fewer than half of the fragments from hydrolysis 1 are single amino acids. B Hydrolysis 2 yields one fewer fragment than hydrolysis 3 C Hydrolysis 2 yields one more dipeptide than hydrolysis 3 D With hydrolysis 1, all fragments formed are seven or fewer amino acid residues long. 5 An electron micrograph of a stained fibre of deoxyhaemoglobin S (HbS) is shown below. Which of the following statement