Muscle Physiology and Energy Production

Miss Johnson explains the muscle unit, focusing on ATP sources: direct phosphorylation, aerobic respiration, and anaerobic glycolysis. She discusses muscle fatigue, isotonic and isometric contractions, and the benefits of aerobic and resistance exercises for muscle endurance and growth.

What is the primary role of ATP in muscle movement?

• To provide energy for muscle contraction

• To store oxygen

• To break down glucose

• To form lactic acid

Which process is the most efficient source of ATP?

• Aerobic respiration

• Lactic acid fermentation

• Direct phosphorylation

• Anaerobic glycolysis

What happens to pyruvic acid during anaerobic glycolysis?

• It is turned into lactic acid

• It is converted into carbon dioxide

• It combines with oxygen

• It releases 34 ATP molecules

What is a common cause of muscle fatigue?

• High levels of creatine phosphate

• Too much ATP

• Lack of oxygen

• Excessive glucose

Why do you breathe harder during exercise?

• To increase glucose levels

• To decrease muscle tone

• To reduce lactic acid

• To supply more oxygen for ATP production

What is an isotonic contraction?

• A contraction that results in movement

• A contraction that increases muscle size

• A contraction that decreases muscle tone

• A contraction with no movement

What is muscle tone?

• Complete relaxation of muscles

• Partial contraction of muscles

• Rapid muscle growth

• Muscle fatigue

Which type of exercise increases muscle endurance?

• Resistance training

• Aerobic exercise

• Static stretching

• Isometric exercises

What is a benefit of aerobic exercise?

• Reduces heart strength

• Decreases metabolism

• Improves coordination

• Increases muscle size

What happens to muscle cells during resistance exercise?

• They decrease in size

• They convert to fat cells

• They increase in number

• They increase in size