Question | Answer |
The supply of ATP depends on | the availability of oxygen &organic energy sources such as glucose & fatty acids |
Aerobic metabolism(respiration) | provides most ATP needed for contraction, uses O2 to generate large amounts of ATP from glucose or fatty acids |
In a resting muscle, most ATP is generated by | aerobic respiration of fatty acids. |
Anaerobic glycolysis(fermentation) | allows the cell to produce ATP in the absence of oxygen, but yield is limited & lactic acid, a toxic end product, is a major factor in muscle fatigue. |
What is used at peak activity to generate ATP | anaerobic glycolysis |
Creatine phosphate | releases stored energy to convert ADP to ATP |
Slow oxidative (SO), slow-twitch, red, or type I fibers | Have high concentrations of myoglobin Used in endurance actvities(areobic): Running a marathon, maintaining posture, or antigravity actities |
Fast glycolytic (FG), fast-twitch, or whit fibers | Used in Short term activites/intsense or powerful activities(anaerobic glycolosis): Hitting a baseball. |
Intermediate(fast oxidative)Type IIA fibers | Most human muscles are mixtures of these fibers Greater resistance to fatigue compared to fast fibers |
Pale muscles(white muscles) are dominated by | fast fibers |
Dark muscles(red muscles) are dominated by | slow fibers and myoglobin |
hypertrophy | is the increase of the size of muscle cells |
Atrophy | reduction or loss of muscle mass |
Anaerobic endurance | Time over which muscular contractions are sustained by glycolysis and ATP/CP reserves |
Aerobic endurance | Time over which muscle can continue to contract while supported by mitochondrial activities |
Myoglobin | A protien which has oxygen attached to it, provides extra oxygen for the muscle to maintain a high level of activity for a longer period of time. |