Amylose and the triglyceride stearin are macromolecules. Students used the enzyme maltase extracted from the fungus Aspergillus oryzae to investigate the properties of enzymes. Fig. 1.1 is a diagram of a maltose molecule. [Figure 1.1]

Mark scheme

Marking points from the official mark scheme (May/June 2025). The mark or mark type is shown in brackets.

1. [1] (a) macromolecule (both are) large / AW, molecules / size / (molecular) mass ; A composed of, many / AW, atoms I composed of more than one molecule
2. [1] (a) polymer composed of, many / three or more / more than two / repeated / repeating, subunits / units / monomers / residues / alpha glucose; A many of the same / similar / chain of for repeated I molecules
3. [1] (b)(i) a-/alpha-, glucose molecule on left with –OH on C1 facing downwards ;
4. [1] (b)(i) α-/alpha-, glucose molecule on right with –OH on C4 facing downwards ; ecf if a single same mistake is made in both, e.g. no –H on C5
5. [1] (b)(i) involvement of water ; must be above or alongside arrow R if below
6. [1] (b)(ii) glycosidic; A glucosidic I incorrect detail of the bond, e.g. ẞ-/beta- / α- / alpha-,1, 6
7. [1] (b)(iii) hydrolysis ;