KW HHB Unit 1 Energy Systems in Muscle Cells

During vigorous exercise, the muscle cells do not get sufficient oxygen to support ..........................

• glycolysis

• the citric acid cycle

• the electron transport chain

• glycolysis and the citric acid cycle

During vigorous exercise, when the muscle cells do not get sufficient oxygen to support the electron transport chain, pyruvate is converted to ..............................

• carbon dioxide

• lactate

• citrate

• oxaloacetate

The conversion of pyruvate to lactate involves the transfer of hydrogen ions from the .............. produced during glycolysis to pyruvate in order to produce lactate.

• NAD

• NADH

• ATP

• ADP and Pi

The transfer of hydrogen ions from the NADH to pyruvate regenerates the ............... needed to maintain ATP production through glycolysis.

• NAD

• NADH

• ATP

• ADP and Pi

During vigorous exercise, when the muscle cells do not get sufficient oxygen to support the electron transport chain, .................... accumulates.

• citrate

• pyruvate

• lactate

• oxaloacetate

During vigorous exercise, when the muscle cells do not get sufficient oxygen to support the electron transport chain, lactate accumulates and muscle ........................ occurs.

• weakness

• atrophy

• wasting

• fatigue

The oxygen debt is repaid when exercise is complete. This allows respiration to provide the energy to convert lactate back to ...................... and glucose.

• citrate

• pyruvate

• lactate

• oxaloacetate

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

• kidney

• muscles

• stomach

Slow-twitch muscle fibres contract relatively .................

• slowly

• quickly

Slow-twitch muscle fibres sustain contractions for ........................ than fast-twitch muscle fibres

• less time

• longer