Energy Systems In Muscle Cells Flashcards
(8 cards)
For lactate metabolism what happens during vigorous exercise?
During vigorous exercise the muscle cells do not get sufficient oxygen to support the electron transport chain, under these conditions pyruvate is converted to lactate
This conversion involves the transfer of hydrogen ions from the NADH produced during glycolysis to pyruvate in order to produce lactate
This regenerates the NAD needed to maintain ATP production through glycolysis
What happens when lactate accumulates?
Lactate accumulates over time and muscle fatigue occurs, the oxygen debt is repaid when exercise is complete, this allows respiration to provide the energy to convert lactate back to pyruvate and glucose in the liver
What are the two types of skeletal muscle fibres?
Slow twitch
Fast twitch
What do slow twitch muscle fibres do?
What activities are they useful for?
How to they generate ATP?
The contract relatively slowly but can sustain contractions for longer
They are useful for endurance activities like long distance running and cycling
They rely on aerobic respiration to generate ATP
What do slow twitch muscle fibres contain?
Many mitochondria
Large blood supply
High concentration of the oxygen storing protein myoglobin
Major storage fuel is fats
What do fast twitch muscle fibres do?
What activities are they useful for?
How do they generate ATP?
Contract relatively quickly over short periods
Useful for activities like sprinting and weightlifting
Generate ATP through glycolysis only
What do fast twitch muscle fibres have?
Fewer mitochondria
Lower blood supply
Storage fuel is glycogen
What are the muscle fibres like for most humans and for athletes?
Most human muscle tissue contains a mixture of both slow and fast twitch muscle fibres
Athletes show distinct patterns of muscle fibres that reflect their sporting activities
