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A level Biology maths help...

Another tricky one...method anyone please?

Hydrolysis of ATP is catalysed by the enzyme ATP hydrolase. box
A student investigated the effect of ATP concentration on the activity of ATP
hydrolase. She used shortening of strips of muscle tissue caused by contraction as
evidence that ATP was being hydrolysed.
She took four slides A, B, C and D, and added strips of muscle tissue of the same
length to each slide.
She then added the same volume of ATP solutions of different concentrations to the
four slides and left each slide for five minutes.
She then recorded the final length of each strip of muscle tissue.
Her results can be seen in Table 1.
Table 1
Slide Concentration of ATP solution added to slide /
×10 6 mol dm 3
A 2
B 4
C 6
D 8

0 8 . 5 The hydrolysis of 1 dm3 of a 1 mol dm−3 solution of ATP releases 30 500 J of energy.
60% of the energy released during the hydrolysis of 1 mol dm−3 of ATP is released as
heat; the rest is used for muscle contraction.
The student added 0.05 cm3 of ATP solution to slide D.
Calculate the energy available from ATP for contraction of the muscle on this slide.

3 marks
Hey I moved this thread to a more specific forum :smile: hopefully people with more knowledge will see this better
0.05cm3 = 5x10-5 dm3
Concentration used: 8x10-6 mol dm-3

5x10-5 x 8x10-6 = 4x10-10 mol dm-3

40% of energy available for contraction in 1mol = 0.4 x 30500 = 12200 J

So 12200 x 4x10-10 = 4.88 x 10-6
Reply 3
Original post by Deborah247
0.05cm3 = 5x10-5 dm3
Concentration used: 8x10-6 mol dm-3

5x10-5 x 8x10-6 = 4x10-10 mol dm-3

40% of energy available for contraction in 1mol = 0.4 x 30500 = 12200 J

So 12200 x 4x10-10 = 4.88 x 10-6

Wow, that's great, Thank you so much!

Please could you just clarify this for me?
5x10-5 x 8x10-6

Is the 5x10-5, the dm to cm?
Original post by Biolife
Wow, that's great, Thank you so much!

Please could you just clarify this for me?
5x10-5 x 8x10-6

Is the 5x10-5, the dm to cm?

No problem, I also had no clue how to answer this question but then my teacher explained it to me and it all made sense.

I converted 0.05cm3 to dm3 by dividing it by 1000 which gives you 5x10-5dm3 or 0.00005dm3

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