Bioenergetics of Muscle Contraction Flashcards
insufficient ATP sources can present as ________ or _______
- muscle weakness
- exaggerated fatigability
exercise and disease states can change the _____ of muscle types
proportion
4 main sources of energy for skeletal muscles
- glycogen
- carbohydrates
- phosphocreatine
- fats
anaerobic metabolism methods
- phosphocreatine
- glycolysis
aerobic metabolism process
Krebs cycle
___________ breaks phosphocreatine into creatine and ATP
creatine kinase
↑ ADP _______ creatine kinase
↑ ATP _______ creatine kinase
- activates
- inhibits
4 effects of creatine supplementation
- ↑ muscle mass
- ↓ body fat
- ↑ short-term strength
- some evidence of protective effect in muscle wasting diseases
what are the potential risks of creatine supplementation?
increased heat production and changes in renal function
the energy investment phase of glycolysis starts with ________ and ends with _____
- glucose
- glyceraldehyde 3-phosphate (x2)
the energy release phase of glycolysis starts with __________ and ends with __________
- glyceraldehyde 3-phosphate
- pyruvate
What are the net products of glycolysis?
2 ATP
2 NADH
2 pyruvate
_____________ is the enzyme that catalyzes the reaction to produce pyruvate
phosphofructokinase (PFK)
__________: an inherited autosomal recessive disorder caused by PFK deficiency
Tarui’s disease
symptoms of Tarui’s disease
- excessive glycogen storage
- discolored/darker urine
- muscle weakness
- cramps
- anemia
- exercise intolerance
what is the result of Tarui’s disease?
lack of PFK prevents the metabolism of glucose into energy and destroys red blood cells
3 concentration conditions that will inactivate PFK
- ↑ ATP
- ↑ phosphocreatine
- ↓ pH
3 concentration conditions that will activate PFK
- ↑ ADP
- ↑ P ion
- ↑ pH
an increase in glycogenolysis is caused by __
↑ sarcoplasmic Ca++ indirectly by circulating catecholamines
a decrease in glycogenolysis is caused by _______
decreasing sarcoplasmic Ca++
What disease is described?
- exercise intolerance
- cramps
- muscle pain and weakness shortly after beginning exercise
- “second wind” after resting
phosphorylase deficiency (McArdles disease in humans)
as the duration of exercise increases and carbohydrate stores decline, utilization of _________ increases
fats
what is the total ATP aerobic production?
38 ATP
what is the key enzyme in the Kreb’s cycle?
isocitrate dehydrogenase
3 conditions that increase the Kreb’s cycle
- ↑ ADP
- ↑ P ion
- ↑ mitochondrial Ca++
↑ ATP has what effect on the Kreb’s cycle?
inhibitory
circulating catecholamines trigger ________ release
glucagon
circulating __________ will trigger glucagon release
catecholamines
what is the purpose of GLUT-4?
insulin-independent glucose transport
there is an increase in type ______ muscle fibers in diabetes
II (fast twitch)
