apple or type of fruit Q4. • ignore type of apple (a) any one from: 1 ignore reference to recording results every 5 minutes or (b) (may) have different volume / amount / sizes concentrations of lipid / lipase ignore reference to human error ignore / measure (same) volume / amount / 1 cm3 lipase don’t know can’t • size of drop allow amount of solution 1 (same) volume / amount / 5 cm3 lipid • (c) amylase has no / little effect on cell / walls / apple allow keep same volumes in the accept ideas that refer to shape of test tubes enzyme being ‘incorrect’ mixed after 3 minutes / same time before mixing • or amylase does not breakdown / digest cell / walls / do not accept temperature apple 1 accept amylase only breaks down / digests starch (b) so that the lipase and the lipid reached the right 1 temperature 1 pectinase breaks down cell / walls / apple allow digest for breakdown (c) any two from allow shape of pectinase fits cell / ignore explanations walls / apple decrease in time or faster (breakdown) 1 • boiling breaks down cell / walls / apple then increase in time or then slower (breakdown) • 1 fastest / least time / optimum at 35°C • (d) 11.6 2 1 (d) any two from: enzyme / pectinase destroyed / denatured / damaged / ignore at more ‘test temperatures’ broken down unqualified do not allow kill 1 test more regularly eg test every minute • any interval < 5min only effect of boiling (relevant) 1 test at smaller temperature intervals • [8] any value <15°C
• apple or type of fruit ignore type of apple 1 (b) (may) have different volume / amount / sizes ignore reference to human error ignore don’t know / can’t measure size of drop 1 (c) amylase has no / little effect on cell / walls / apple accept ideas that refer to shape of enzyme being ‘incorrect’ or amylase does not breakdown / digest cell / walls / apple accept amylase only breaks down / digests starch 1 pectinase breaks down cell / walls / apple allow digest for breakdown allow shape of pectinase fits cell / walls / apple 1 boiling breaks down cell / walls / apple 1 (d) 11.6 1 enzyme / pectinase destroyed / denatured / damaged / broken down do not allow kill 1 only effect of boiling (relevant) 1 [8] Q4. (a) any one from: ignore reference to recording results every 5 minutes or concentrations of lipid / lipase • (same) volume / amount / 1 cm3 lipase allow amount of solution • (same) volume / amount / 5 cm3 lipid allow keep same volumes in the test tubes • mixed after 3 minutes / same time before mixing do not accept temperature 1 (b) so that the lipase and the lipid reached the right temperature 1 (c) any two from ignore explanations • decrease in time or faster (breakdown) • then increase in time or then slower (breakdown) • fastest / least time / optimum at 35°C 2 (d) any two from: ignore ‘test at more temperatures’ unqualified • test more regularly eg test every minute any interval < 5min • test at smaller temperature intervals any value <15°C
practical-5-food-tests.docx