The Student Room Group

Biology q

Hi everyone, Please could someone help me with this q?Lactase is an enzyme that breaks down lactose into glucose and galactose.A student made some alginate beads containing lactase.The student added 10 beads to 20 cm3 of a solution of lactose, as shown in Figure 9. The student timed how long it took for glucose to be produced.The experiment was repeated using 15, 20 and 25 beads.
Original post by Pineapple27272
Hi everyone, Please could someone help me with this q?Lactase is an enzyme that breaks down lactose into glucose and galactose.A student made some alginate beads containing lactase.The student added 10 beads to 20 cm3 of a solution of lactose, as shown in Figure 9. The student timed how long it took for glucose to be produced.The experiment was repeated using 15, 20 and 25 beads.

sorry, what's the question? :smile:
Original post by fifi5768
sorry, what's the question? :smile:


The results are shown in Figure 10.
Number of beads containing lactose : Time taken to produce glucose in seconds
10 = 240
15 = 210
20 = 150
25 = 120

(i) What is the rate of reaction for 25 beads?
A 0.008 s−1
B 0.04 s−1
C 0.21 s−1
D 4.8 s−1
Original post by fifi5768
so rate is equal to basically the amount / time
25/120 = 0.21

i think the answer is C, do you have a mark scheme?

That’s exactly what I thought but it says A?!
Original post by Pineapple27272
That’s exactly what I thought but it says A?!

The answer is A because rate of reaction (s–1) = 1 / time taken (s), so 1/120 = 0.008

Quick Reply