Energy Systems in Muscle Cells Flashcards
What happens during vigorous exercise?
The muscle cells do not get sufficient oxygen to support the electron transport chain.
What happens in anaerobic conditions?
Pyruvate is converted to lactate.
What does the conversion of pyruvate to lactate involve?
The transfer of hydrogen from NADH produced during glycolysis to pyruvate in order to produce lactate.
How is ATP production through glycolysis maintained?
The transfer of hydrogen from NADH regenerates the NAD.
When does muscle fatigue occur?
When lactate accumulates.
When is the oxygen debt repaid?
When exercise is complete.
What happens as oxygen debt is repaid?
Respiration provides the energy to convert lactate back to pyruvate and glucose in the liver.
What are the types of skeletal muscle fibres?
Fast twitch muscle fibres
Slow twitch muscle fibres
What is the function of slow twitch muscle fibres?
They contract relatively slowly, but can sustain contractions for longer.
In what activities are slow twitch muscle fibres used?
Endurance activities such as long-distance running, cycling or cross-country skiing.
What structures do slow twitch muscle fibres have to increase the rate of aerobic respiration?
Many mitochondria
Large blood supply
High concentration of oxygen-storing protein, myoglobin
What is the major storage fuel of slow twitch muscle fibres?
Fat
What is the function of fast twitch muscle fibres?
The contract relatively quickly, over short periods. They are useful for activities like weightlifting ot sprinting.
How do fast twitch muscle fibres produce ATP?
Through glycolysis.
What are the features of fast twitch muscle fibres?
Fewer mitochondria and a lower blood supply.
