Please choose the best answer option for each part. Part A. Which one of the fol
ID: 3511328 • Letter: P
Question
Please choose the best answer option for each part.
Part A. Which one of the following statements concerning creatine phosphate and creatine phosphokinase in muscle is incorrect?
a. During contraction creatine phosphokinase located on the myofibrils will convert ADP and creatine phosphate to ATP and creatine.
b. A reserve of creatine phosphate is established during contraction, when metabolic pathways are more easily able to maintain a constant ATP level.
c. Creatine phosphate is the first energy reserve to rephosphorylate ATP and sustain contractility.
d. An endogenous biosynthesis pathway normally generates sufficient creatine to replace that lost to spontaneous formation of creatinine.
Part B. Which one of the following statements concerning adaptive mechanisms affecting muscle metabolism is correct?
a. Contractile activity decreases the concentration of PGC-1 signaling molecules, such as AMP, reactive nitrogen species, and reactive oxygen species.
b. PGC-1 interacts with transcription factors to play a key role in regulating the expression of genes that influence muscle fiber type, mitochondrial biogenesis, and capacity for fatty acid oxidation.
c. AMPK serves to inhibit energy producing pathways in skeletal and cardiac muscle during exercise.
d. AMP concentrations in muscle decrease during exercise due to stimulation of the myokinase reaction.
Part C. Which one of the following statements concerning metabolic mechanisms of muscle fatigue is correct?
a. Depletion of the adipose tissue lipid supply is the most significant cause of exhaustion during high-intensity exercise.
b. Glucose circulating in the blood is not available to contribute to muscle metabolism during exercise.
c. Lactic acid accumulation and lower myoplasmic pH are the most significant causes of fatigue during lower-intensity exercise.
d. Glycogen depletion is the major contributing factor to the duration of lower-intensity exercise.
e. Slow-twitch fiber types are better able to derive ATP from glycogen use, while fast- twitch fibers are better able to derive ATP from fatty acid use.
Explanation / Answer
Part A. Which one of the following statements concerning creatine phosphate and creatine phosphokinase in muscle is incorrect?
Answer- b. A reserve of creatine phosphate is established during contraction, when metabolic pathways are more easily able to maintain a constant ATP level.
Part B. Which one of the following statements concerning adaptive mechanisms affecting muscle metabolism is correct?.
Answer- c. AMPK serves to inhibit energy producing pathways in skeletal and cardiac muscle during exercise
Part C. Which one of the following statements concerning metabolic mechanisms of muscle fatigue is correct?
Answer- c. Lactic acid accumulation and lower myoplasmic pH are the most significant causes of fatigue during lower-intensity exercise.