Myofibrils

This parody (written by Greg Crowther) is sung to the tune of "My Sharona" (written by Doug Fieger and Burton Averre and performed by The Knack).

This song outlines the molecular mechanisms by which muscle cells contract. The major players include calcium, troponin, tropomyosin, actin, and myosin.

Ooh my little filaments, filaments --
Actin and myosin myofibrils:
Proteins that are long and dense, long and dense,
Making up the structure of the myofibrils.

CHORUS:
Signal from the brain rides the nerve to the muscle,
Where the myosin inside will slide past the actin of the
My-my-my-y-y, woo! Muh-muh-muh-myofibrils.

Add a little calcium, calcium
To the cytoplasm near the myofibrils.
It will turn troponin on, troponin on,
Causing the contraction of the myofibrils.

CHORUS

Muscles need energy, energy,
Most of which is needed by the myofibrils.
Myosin burns ATP, ATP
Fueling the contractions of the myofibrils.

CHORUS

• MP3 (by Science Groove)

• music video

Songs like this one can be used during class meetings and/or in homework assignments. Either way, the song will be most impactful if students DO something with it, as opposed to just listening.

An initial, simple follow-up activity could be to answer the study questions below. A more extensive interaction with the song might entail (A) learning to sing it, using an audio file and/or sheet music as a guide, and/or (B) illustrating it with pictures, bodily poses, and/or bodily movements. The latter activity could begin with students identifying the most important or most challenging content of the song, and deciding how to illustrate that particular content.

(1) Define the term "myofibril."

(2) Put the following in order of increasing size: muscle, muscle fiber, myofibril, myofilament.

(3) The lyrics refer to myosin sliding past actin. You can't see this with the naked eye, but you can see your muscles getting shorter and fatter as you contract them. How does the microscopic movement of the proteins relate to the observable macroscopic change?

(4) As noted in the chorus, electrical signals originating in the brain are delivered to muscles. Which specific cells deliver these signals directly to muscle cells?

(5) The song says that calcium is added to the cytoplasm (sarcoplasm). Where does the calcium come from, and what triggers its movement into the cytoplasm?

(6) In your own words, explain what is meant by the line, "It will turn troponin on ... causing the contraction of the myofibrils."

(7) The song notes that "myosin burns ATP." What exactly happens to ATP when it is "burned," and when exactly does this happen in the cycle of interactions between actin and myosin?

(8) The song notes that "myosin burns ATP." What is the OTHER major consumer of ATP within contracting muscle cells?

(9) Considering the specific content covered by this song, is there anything important that is missing, unclear, or misleading? If so, what?