Page 1 of 71
GMS 6474 FINAL EXAM*** 200 QUESTIONS AND
VERIFIED ANSWERS | 2026/2027 UPDATE
What does titin do in the sarcomere
❖ Structural protein
How many zones can you see when the sarcomere is relaxed
❖ All zones can be seen in relaxed state
How many zones can be seen when the sarcomere is
contracted
❖ Sarcomere shortens
❖ I band shortens
❖ H zone disappears
❖ Thick and thin filaments overlap dont shorten
,Page 2 of 71
What is the contractile unit of skeletal muscle
❖ The sarcomere
What is the main component of the thick filaments
❖ Myosin
❖ Have heavy and light chains
❖ Motor heads that move it along the thin filament
What is the largest protein in the body
❖ Titin
What are the main components of the thin filaments
❖ 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)
,Page 3 of 71
❖ Tropomodulin (on end of actin, in middle of sarcomere)
❖ Alpha-actinin (anchors actin to z-line)
What does desmin do in the sarcomere
❖ Interacts with alpha-actinin to anchor z-disc to
sarcolemma
What does dystrophin do in the sarcomere
❖ Connects sarcomere to sarcolemma
❖ Stabilizes the sarcolemma to prevent damage during
contractions
What does the sr store
❖ Proteins and calcium
What is the role of the transverse tubules in the muscle fiber
, Page 4 of 71
❖ Allow inside of muscle to communicate with the outside
of the muscle
How is a sarcomere measured
❖ From z-disc to z-disc
What is contained in the i band of the sarcomere & what color
is the band
❖ Thin filaments
❖ Titin
❖ Z-disc
❖ Light (isotropic)
What is contained in the a band of the sarcomere & what
color is the band
❖ Thick filaments
❖ Thin filaments
❖ Dark (scatters light)
GMS 6474 FINAL EXAM*** 200 QUESTIONS AND
VERIFIED ANSWERS | 2026/2027 UPDATE
What does titin do in the sarcomere
❖ Structural protein
How many zones can you see when the sarcomere is relaxed
❖ All zones can be seen in relaxed state
How many zones can be seen when the sarcomere is
contracted
❖ Sarcomere shortens
❖ I band shortens
❖ H zone disappears
❖ Thick and thin filaments overlap dont shorten
,Page 2 of 71
What is the contractile unit of skeletal muscle
❖ The sarcomere
What is the main component of the thick filaments
❖ Myosin
❖ Have heavy and light chains
❖ Motor heads that move it along the thin filament
What is the largest protein in the body
❖ Titin
What are the main components of the thin filaments
❖ 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)
,Page 3 of 71
❖ Tropomodulin (on end of actin, in middle of sarcomere)
❖ Alpha-actinin (anchors actin to z-line)
What does desmin do in the sarcomere
❖ Interacts with alpha-actinin to anchor z-disc to
sarcolemma
What does dystrophin do in the sarcomere
❖ Connects sarcomere to sarcolemma
❖ Stabilizes the sarcolemma to prevent damage during
contractions
What does the sr store
❖ Proteins and calcium
What is the role of the transverse tubules in the muscle fiber
, Page 4 of 71
❖ Allow inside of muscle to communicate with the outside
of the muscle
How is a sarcomere measured
❖ From z-disc to z-disc
What is contained in the i band of the sarcomere & what color
is the band
❖ Thin filaments
❖ Titin
❖ Z-disc
❖ Light (isotropic)
What is contained in the a band of the sarcomere & what
color is the band
❖ Thick filaments
❖ Thin filaments
❖ Dark (scatters light)
