1.8 Flashcards
What are the conditions that lactate are made in
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.
How is Pyruvate converted into lactate
This conversion of pyruvate to lactate 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.
How is Lactate converted back into Pyruvate and Glucose
As oxygen “debt” build up lactate accumulates 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 properties of Slow Twitch Muscle Fibres
Contract relatively slower
Best for endurance activities (Cycling, Long Distance Running): sustain contraction for a long time
Rely on aerobic respiration to generate ATP
Have many mitochondria
Have a large concentration of oxygen-storing myoglobin and a large blood supply
Major storage fuel is fat
What are the properties of Fast Twitch Muscle Fibres
Contract relatively quickly
Best for activities requiring bursts of energy (Sprinting, weightlifting): sustain contraction for a short time
Generate ATP through glycolysis
Have fewer mitochondria
Have a lower blood supply
Major storage fuel is glycogen
What is the difference of muscle fibre types found in people and 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
