function of skeletal muscle tissue

Question 1

Transverse tubules extend across the

Answer 1

sarcoplasm at right angles to the long axis of the muscle fiber

Question 2

Membrane has ion pumps that continually

Answer 2

transport calcium ions inward from the sarcoplasm

Question 3

Each myofibril contains

Answer 3

thousands of thick and thin myofilaments

Question 4

Four different kinds of protein molecules

Answer 4

make up myofilaments

Question 5

Myosin “heads” are chemically attracted to

Answer 5

actin molecules

Question 6

Myosin “heads” are known as cross bridges when attached to

Answer 6

actin

Question 7

Actin

Answer 7

globular protein that forms two fibrous strands twisted around each other to form the bulk of the thin filament

Question 8

Tropomyosin

Answer 8

protein that blocks the active sites on actin molecules

Question 9

Troponin

Answer 9

protein that holds tropomyosin molecules in place

Question 10

Thin filaments attach to both

Answer 10

Z disks (Z lines) of a sarcomere and extend partway toward the center

Question 11

• Thick myosin filaments do not attach

Answer 11

to the Z disks