Animation: Sliding Filament Theory
http://tinyurl.com/qcu8f86
1. The stripey appearance of ________________ results from the regular arrangement of ______________ within the
_________________. The ___________________ is one of the segments into which the __________________ is divided. The
______________ provides an attachment for myosin filaments. The ____ - line provides an attachment for __________________.
2. The A band is the darker segment containing ____________________. The I band is the _______________ containing
____________________. The ___ - band is the lighter section within the ____- band where only ____________ is present.
3. Describe the position of tropomyosin when muscle is relaxed.
4. Describe the position of tropomyosin when muscle in contracted.
5. ATP provides the energy for the myosin head to do what?
3. When does muscle contraction occur?
4. What are T-tubules?
5. What happens when calcium binds to troponin molecules?
6. What happens after the action potential has passed?
7. Where does calcium return to?
PART 1: “The Sliding Filament Theory of Muscle Contraction”
Go to http://tinyurl.com/cfnc666 read, “The Sliding Filament Theory of Muscle Contraction” and answer the following
questions:
1. Thick filaments are made of __________________ while thin filaments are made of __________________.
2. How did the scientists researching the sliding filament theory in 1954 know that actin slides while myosin remains
stationary?
3. Define sliding filament theory.
4. What structure separates one sarcomere from another sarcomere?
5. In the analogy with the person standing between the bookcase – what does each of the following represent.
a. bookcase
b. ropes
c. you (the person in the middle)
d. your arms
6. What would a globular part of a protein indicate? (you may have to look this up).
7. Define power stroke. What is required for a power stroke?
8. What causes rigor mortis?
9. What two cofactors are required for muscle contraction? Describe the function of each.
10. How do troponin and tropomyosin regulate muscle contracting?
Yale Histology Lab - http://tinyurl.com/png6aur
Go to the section titled, “Slides” and looking at slides 1-6
1. Draw a quick sketch (its fine to draw just a part of the slide) and label the endomysium, perimysium, nucleus, and muscle
fiber.
2. Draw a quick sketch (its fine to draw just a part of the slide) and label the endomysium, perimysium, nucleus, and muscle
fiber.
3. This slide will take you the longest. Sketch what you see. You need to be able to draw enough to label the following:
myofibril, sarcomere, Z-disk, I band, A band, M-line, sarcoplasmic reticulum and T-tubule.
Which band is light?
Which band is dark?
What filaments are in the I band? What filaments are in the A band?
5. Sketch and label – motor end plate, motor nerve, and muscle cell.
6. This slide may take a while to load. Draw enough to label the mitochondria, synaptic vesicle, synaptic cleft, presynaptic
neuron, muscle cell, and motor end plate.
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