UNIT 1 - KA8 Flashcards
During vigorous exercise what do muscle cells not get enough of and what happens under these conditions
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
What does the conversion of pyruvate to lactate involve
This conversion involves the transfer of hydrogen from the NADH produced during glycolysis to pyruvate in order to produce lactate
What does the conversion of pyruvate into lactate regenerate
This regenerates the NAD needed to maintain ATP production through glycolysis
What happens when lactate accumulates
Lactate accumulates and muscle fatigue occurs.
What happens when the oxygen debt is repaid
This allows respiration to provide the energy to convert lactate back to pyruvate and glucose in the liver
How many molecules of ATP are generated per glucose molecule when cells do not get sufficient oxygen to support the electron transport chain
2 ATP molecules are generated per glucose molecule when muscle cells do not get sufficient oxygen to support the electron transport chain.
Name the two types of skeletal muscle fibres
Type 1 - SLOW TWITCH muscle fibres
Type 2 - FAST TWITCH muscle fibres
What is myoglobin
- an oxygen storing protein myoglobin
How does myoglobin compare to haemoglobin
- myoglobin has a stronger affinity for oxygen than haemoglobin
What function of myoglobin benefits skeletal muscle cells where it is found?
This is a benefit as myoglobin can extract oxygen from the blood for use by muscle cells - (especially those in slow - twitch muscle fibres)
What do most human muscle tissues contain
Most human muscle tissues contains a mixture of both slow and fast twitch muscle fibres that reflect their sporting activity
What is the speed of contraction of slow twitch muscle fibres
Contract More slowly /slower
What is the speed of contraction of fast twitch muscle fibres
Contract More quickly - faster
What is the length of time contraction is sustained in slow twitch muscle fibres
Contraction is sustained for a longer time
What is the length of time contraction is sustained in fast twitch muscle fibres
Contraction is sustained for a shorter time
What is the length of time before muscles fatigue in slow twitch muscle fibres
Longer time before muscles fatigue
What is the length of time before muscles fatigue in fast twitch muscle fibres
Shorter time before muscles fatigue
What is the respiratory pathway mainly used to generate ATP in slow twitch muscle fibres
Aerobic respiration mainly used to generate ATP
What is the respiratory pathway mainly used to generate ATP in fast twitch muscle fibres
Glycolysis is mainly used to generate ATP
What is the number of mitochondria present in slow twitch muscle fibres
Many mitochondria
What is the number of mitochondria present in fast twitch muscle fibres
Fewer mitochondria
What is the volume of blood supplied to slow twitch muscle fibres
Large blood supply to slow twitch muscle fibres
What is the volume of blood supplied to fast twitch muscle fibres
Lower blood supply to fast twitch muscle fibres
What is the concentration of myoglobin in cells of slow twitch muscle fibres
High concentration of myoglobin in cells of slow twitch muscle fibres
