Muscle Structure, Contraction, and Exercise Quiz

What is the functional contractile unit of muscle?

• Sarcomere

• Actin

• Myosin

• Tropomyosin

Which protein is associated with stabilizing F-actin and coordinating conformational changes among actin subunits during contraction?

• Myosin

• Tropomyosin

• Troponin

• Titin

What is the primary source of energy in muscle during prolonged exercise?

• Glucose

• Creatine Phosphate

• Lactate

• Fatty Acids

Which type of muscle fibers rely on glycogen and anaerobic glycolysis for short bursts of contraction?

• Cardiac Muscle

• Intermediate Fibers

• Slow-Oxidative Fibers

• Fast-Glycolytic Muscle

What is the purpose of strength or resistance training?

• Enhance muscle endurance

• Increase muscle flexibility

• Increase muscle force production

• Improve cardiovascular health

Which enzyme activity increases in all muscle fiber types with endurance training, resulting in greater ATP production?

• Citrate Synthase

• Lactate Dehydrogenase

• Creatine Kinase

• Hexokinase

What is the primary biochemical change in muscle cells due to endurance training?

• Reduced ATP production

• Decreased mitochondrial number

• Enhanced capacity to metabolize fat

• Increased glycolytic enzyme activity

Which ATPase is required for muscle contraction and is responsible for the dissociation of the actomyosin cross-bridge?

• ATP Synthase

• Myosin-ATPase

• Ca2+-ATPase

• Na+/K+-ATPase

What is the main structural and functional element of muscle?

• Myosin

• Actin

• Sarcomere

• Tropomyosin

Which protein is responsible for the movement of tropomyosin to expose the myosin-binding site on actin during muscle contraction?

• Troponin

• Titin

• Myosin

• Tropomyosin