Chapter 10 MAP

Thin filaments are mostly made of the protein A. actin. B. tropomyosin. C. myosin. D. titin. E. nebulin.

A. actin

Which structure contains the motor end plate? A. 5 B. 2 C. 8 D. 1 E. 3

B. 2

All of the following proteins are part of the thin filaments except A. troponin. B. titin. C. tropomyosin. D. actin. E. None of the answers is correct; there are no exceptions.

B. titin

Identify the structure where ATP is produced. A. 3 B. 7 C. 1 D. 2 E. 6

C. 1

The region of the sarcomere containing the thick filaments is the A. H band. B. Z line. C. A band. D M line. E. I band.

C. A band

The area in the center of the A band that contains no thin filaments is the A. zone of overlap. B. Z line. C. H band. D. I band. E. M line.

C. H band

The region of the sarcomere that always contains thin filaments is the A. A band. B. M line. C. I band. D. H band. E. Z line.

C. I band

Thick filaments are made of the protein A. actin. B. titin. C. myosin. D. tropomyosin. E. nebulin.

C. myosin

The structural theory that explains how a muscle fiber contracts is called the ________ theory. A. action-myosin interaction B. muscle contraction C. sliding filament D. excitation-contraction coupling E. neuromuscular

C. sliding filament

Each thin filament consists of A. a double strand of myosin molecules. B. chains of myosin molecules. C. two actin protein strands coiled helically around each other. D. six molecules coiled into a helical structure. E. a rod-shaped structure with "heads" projecting from each end.

C. two actin protein strands coiled helically around each other

Identify the structure(s) where ATP is consumed? A. 7 B. 3 and 7 C. 3 D. 3 and 6 E. 6

D. 3 and 6

The skeletal muscle complex known as the triad consists of A. filaments, myofibrils, and sarcomeres. B. actin, myosin, and sarcomeres. C. actin, myosin, and titin filaments. D. a transverse tubule and two terminal cisternae. E. A bands, H bands, and I bands.

D. a transverse tubule and two terminal cisternae

Cross-bridges are portions of A. tropomyosin molecules. B. actin molecules. C. calcium ions. D. myosin molecules. E. troponin molecules.

D. myosin molecules

Which of the following best describes the term titian? A. storage and release site for calcium ions B. repeating unit of striated myofibrils C. thin filaments are anchored here D. protein that accounts for elasticity of resting muscle E. largely made of myosin molecules

D. protein that accounts for elasticity of resting muscle

The repeating unit of a skeletal muscle fiber is the A. sarcolemma. B. myofilament. C. sarcoplasmic reticulum. D. myofibril. E. sarcomere.

E. sarcomere

At rest, active sites on the actin are blocked by A. calcium ions. B. ATP molecules. C. myosin molecules. D. troponin molecules. E. tropomyosin molecules.

E. tropomyosin molecules

Skeletal muscle fibers are formed from embryonic cells called a. myoblasts. b. myomeres. c. myofibrils. d. sarcomeres. e. fascicles.

a. myoblasts

The plasma membrane of a skeletal muscle fiber is called the a. sarcoplasm. b. sarcolemma. c. sarcomere. d. sarcosome. e. sarcoplasmic reticulum.

b. sarcolemma

Which of the following best describes the term sarcoplasmic reticulum? a. largely made of myosin molecules b. storage and release site for calcium ions c. thin filaments are anchored here d. protein that accounts for elasticity of resting muscle e. repeating unit of striated myofibrils

b. storage and release site for calcium ions

In a sarcomere, the central portion of thick filaments are linked laterally by proteins of the a. A band. b. Z line. c. M line. d. I band. e. H band.

c. M line

Which region of the sarcomere gives rise to the structure (band or line) indicated by the arrow? a. the region of the resting sarcomere that only contains thick filaments b. the region of the sarcomere that contains only thin filaments c. the point of connection for adjacent tails of the thick filaments d. the boundary between adjacent sarcomeres

c. the point of connection for adjacent tails of the thick filaments

Interactions between actin and myosin filaments of the sarcomere are responsible for a. muscle fatigue. b. the conduction of neural stimulation to the muscle fiber. c. the striped appearance of skeletal muscle. d. muscle contraction. e. muscle relaxation.

d. muscle contraction