Lecture 9 Test 2

Question 1

Functions of controlled muscle contractions

Answer 1

1

Question 2

Skeletal muscle fibers

Answer 2

• Muscle fiber=muscle cell
• Lie parallel to each other, bundled by connective tissue
• Fibers composed of myofibrils
• Regular arrangement of thin and thick filaments

Question 3

Myosin

Answer 3

• Forms thick filaments

- Protein consisting of two identical subunits (golf club)

Question 4

Actin

Answer 4

• Main component of thin filaments
• Interacts with myosin cross bridge
• Tropomyosin, troponin

Question 5

A band

Answer 5

thick filaments overlap with thin filaments

Question 6

I band

Answer 6

remaining portion of thin filaments that do not project into A band

Question 7

H zone

Answer 7

1

Question 8

M line

Answer 8

1

Question 9

Thick filament structure

Answer 9

• Myosin molecule: two identical, club shaped subunits with tails intertwined, heads form cross bridges
• Actin binding site (head)
• ATPase site (head)
• Two hinge points one along tail other at tail head junction
• Many myosin molecules parallel (oriented in each direction)