1. Limited time only! Sign up for a free 30min personal tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

ATP in Muscle Contractions

  1. Feb 4, 2006 #1
    >> Calculate approximately how many molecules of ATP are required for a standard muscle like the biceps during the contraction phase of a single twitch.

    I honestly do not even know where to begin here... I don't think he wants us to go through and just outline Glycolysis/Kreb's Cycle/ETC because that's just producing ATP in general, not for a specific contraction. And that's not saying how much is NEEDED...

    I've looked around on the internet but can't really seem to come up with an answer. I know that calcium is needed but again, I can't figure out how much.

    Does anyone think they could help me out? Thanks
     
  2. jcsd
  3. Aug 14, 2017 #2

    TeethWhitener

    User Avatar
    Science Advisor
    Gold Member

    There are tons of different ways to approach this problem, from the very simple to the very involved. I'll go a very simple way. Let's take the bicep, for instance. Let's say you lift a 10kg weight 0.5m directly upward (using only your bicep somehow). This requires your bicep to do:
    $$W = mgh = (10kg)(9.8m/s^2)(0.5m) = 49J$$
    worth of work. ATP hydrolysis releases 30.5 kJ mol-1. This means that the number of moles of ATP required to do 49 J worth of work is:
    $$\frac{49J}{30500J\cdot mol^{-1}}=1.6\times 10^{-3} mol$$
    To get number of molecules, simply multiply by Avogadro's number:
    $$(1.6\times 10^{-3} mol)(6.022 \times 10^{23} mol^{-1}) = 9.6 \times 10^{20}$$
    So an order of magnitude estimate would be roughly 1021 molecules of ATP per muscle contraction.
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?
Draft saved Draft deleted



Similar Discussions: ATP in Muscle Contractions
  1. ATP, Phosphate (Replies: 1)

  2. How many moles of ATP (Replies: 3)

Loading...