2025 BIO 201L Lab 7 The Muscular System COMPLETE NEW LAB
SOLUTION Straighterline
Student Name:
Access Code (located on the lid of your lab kit):
Lab Report Format Expectations
Utilize college level grammar and professional formatting when completing this
worksheet. Submissions without proper formatting, all required photos or
sufficient responses will be rejected.
Pre-lab Questions
1. How do banding patterns change when a muscle contracts?
The muscle organ is the whole muscle. Muscle fibers are the individual
cells. Myofibrils are rods inside muscle fibers made of repeating units, and
myofilaments are the actin and myosin proteins involved in contraction.
2. What is the difference between a muscle organ, a muscle fiber,
myofibril and a myofilament?
ATP binds to myosin allowing detachment from actin, hydrolyzes to ADP + Pi to
cock
the myosin head, which then binds to actin and causes the power stroke.
ATP is required to repeat this cycle.
3. Outline the molecular mechanism for skeletal muscle contraction. At
what point is ATP used and why?
ATP is required to break cross-bridges between actin and myosin. In death,
ATP is depleted, so muscles stiffen in a contracted state (rigor mortis).
,4. Explain why rigor mortis occurs.
Rigor Mortis happens because the remaining ATP is utilized for muscle
contraction, but once that ATP is depleted, there is no energy available for
actin and myosin to detach, resulting in the muscles remaining contracted
and stiff.
, Lab 7 The Muscular System BIO201L
EXPERIMENT 1: TENDONS AND LIGAMENTS
Introduction Questions
1. How does the extracellular matrix of connective tissues contribute to its function?
The extracellular matrix of connective tissues consists of collagen and
elastic fibers, which provide mechanical support and strength.
2. Why are tendons and ligament tissues difficult to heal?
Tendons and ligaments are challenging to heal because they have a limited
blood supply, resulting in a longer healing process.
Data and Observations
1. Label the arrows in the slide images below based on your
observations from the experiment.
A. Chondrocytes
B. Collagen
C. Collagen Fibers
D. Skeletal Muscle Fibers
E. Nuclei
F. Collagen Fibers
SOLUTION Straighterline
Student Name:
Access Code (located on the lid of your lab kit):
Lab Report Format Expectations
Utilize college level grammar and professional formatting when completing this
worksheet. Submissions without proper formatting, all required photos or
sufficient responses will be rejected.
Pre-lab Questions
1. How do banding patterns change when a muscle contracts?
The muscle organ is the whole muscle. Muscle fibers are the individual
cells. Myofibrils are rods inside muscle fibers made of repeating units, and
myofilaments are the actin and myosin proteins involved in contraction.
2. What is the difference between a muscle organ, a muscle fiber,
myofibril and a myofilament?
ATP binds to myosin allowing detachment from actin, hydrolyzes to ADP + Pi to
cock
the myosin head, which then binds to actin and causes the power stroke.
ATP is required to repeat this cycle.
3. Outline the molecular mechanism for skeletal muscle contraction. At
what point is ATP used and why?
ATP is required to break cross-bridges between actin and myosin. In death,
ATP is depleted, so muscles stiffen in a contracted state (rigor mortis).
,4. Explain why rigor mortis occurs.
Rigor Mortis happens because the remaining ATP is utilized for muscle
contraction, but once that ATP is depleted, there is no energy available for
actin and myosin to detach, resulting in the muscles remaining contracted
and stiff.
, Lab 7 The Muscular System BIO201L
EXPERIMENT 1: TENDONS AND LIGAMENTS
Introduction Questions
1. How does the extracellular matrix of connective tissues contribute to its function?
The extracellular matrix of connective tissues consists of collagen and
elastic fibers, which provide mechanical support and strength.
2. Why are tendons and ligament tissues difficult to heal?
Tendons and ligaments are challenging to heal because they have a limited
blood supply, resulting in a longer healing process.
Data and Observations
1. Label the arrows in the slide images below based on your
observations from the experiment.
A. Chondrocytes
B. Collagen
C. Collagen Fibers
D. Skeletal Muscle Fibers
E. Nuclei
F. Collagen Fibers
