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GMS 6474 FINAL EXAM QUESTIONS
AND ANSWERS (GRADED A+)
Question :what does the SR store
Correct answer:proteins and calcium
Question :what is the role of the transverse tubules in the
muscle fiber
Correct answer:allow inside of muscle to communicate
with the outside of the muscle
Question :how is a sarcomere measured
Correct answer:from z-disc to z-disc
Question :what is contained in the I band of the sarcomere
& what color is the band
Correct answer:thin filaments
titin z-disc light (isotropic)
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Question :what is contained in the A band of the
sarcomere & what color is the band
Correct answer:thick filaments
thin filaments dark (scatters light)
Question :what is contained in the H zone & what color is
the band
Correct answer:thick filaments
light no barbs or myosin middle zone of the sarcomere
Question :what is contained in the M line
Correct answer:in the middle of the sarcomere, middle of
H zone thick filaments myomesin
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Question :what does titin do in the sarcomere
Correct answer:structural protein
Question :how many zones can you see when the
sarcomere is relaxed
Correct answer:all zones can be seen in relaxed state
Question :how many zones can be seen when the
sarcomere is contracted
Correct answer:sarcomere shortens
I band shortens H zone disappears thick and thin filaments overlap DONT shorten
Question :what is the contractile unit of skeletal muscle
Correct answer:the sarcomere
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Question :what is the main component of the thick
filaments
Correct answer:myosin
have heavy and light chains motor heads that move it along the thin filament
Question :what is the largest protein in the body
Correct answer:titin
Question :what are the main components of the thin
filaments
Correct answer:actin (where myosin binds)
troponin (moves tropomyosin when Ca2+ is present) tropomyosin (covers actin active site) nebulin (sets thin filament length) CapZ (anchors actin to Z-line on z-disc side) Tropomodulin (on end of actin, in middle of sarcomere) alpha-actinin (anchors actin to z-line)
