energy systems in muscle cells

Question 1

what happens when muscles are out through vigorous exercise?

Answer 1

muscle cells do not get sufficient oxygen to support the electron transport chain

Question 2

what must happen when muscle cells don’t get sufficient oxygen?

Answer 2

pyruvate is converted to lactate.

Question 3

what does this conversion involve?

Answer 3

he transfer of hydrogen from the NADH produced during glycolysis to pyruvate in order to produce lactate. . This regenerates the NAD needed to maintain ATP production through glycolysis.

Question 4

when the lactate accumulates causing…

Answer 4

the muscle to fatigue

Question 5

what happens once exercise is over?

Answer 5

the oxygen debt is paid back allowing respiration to produce the energy required to covert the lactate back to pyruvate and glucose in the liver.

Question 6

describe slow-twitch muscles

Answer 6

Slow-twitch muscle fibres contract relatively slowly, but can sustain contractions for longer. They are useful for endurance activities such as long-distance running, cycling or cross-country skiing.

Question 7

describe the inner workings of slow-twitch muscles

Answer 7

Slow-twitch muscle fibres rely on aerobic respiration to generate ATP and have many mitochondria, a large blood supply and a high concentration of the oxygen-storing protein myoglobin.The major storage fuel of slow-twitch muscle fibres is fats.

Question 8

describe fast-twitch muscles

Answer 8

Fast-twitch muscle fibres contract relatively quickly, over short periods. They are useful for activities such as sprinting or weightlifting.

Question 9

describe the inner workings of fast-twitch muscles

Answer 9

Fast-twitch muscle fibres can generate ATP through glycolysis only and have fewer mitochondria and a lower blood supply compared to slow-twitch muscle fibres.The majorstorage fuel of fast-twitch muscle fibres is glycogen.