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Ch11 Musclar tissue5
Muscle metabolism
| 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. |