Muscles (Microscopic)

Question 1

Define sarcomere

Answer 1

The basic contractile unit of the muscle cell

Question 2

Where is the location of a muscle cell/ muscle fiber

Answer 2

between two successive “Z” lines

Question 3

What four different types of molecules make up myofilaments

Answer 3

• Myosin
• Actin
• Tropomyosin
• Troponin

Question 4

What is myosin and what is its function

Answer 4

• Protein
• Attracted to actin and acts as a cross bridge when attached to actin

Question 5

What is actin and what is its function

Answer 5

• Protein
• Forms two fibrous strands that twist around each other, forming thin filament

Question 6

What is tropomyosin and what is its function

Answer 6

• Protein
• Blocks active sites on actin molecules

Question 7

What is troponin and what is its function

Answer 7

• Protein
• Holds tropomyosin molecules in place

Question 8

Where do thin actin filaments attach?

Answer 8

Z lines (Z disks)

Question 9

T/F: Along with the actin filaments, thick myosin filaments also attach to the Z lines

Answer 9

False: They are located in the A bands