Question

Using the following table for reference, describe and explain each characteristic, especially noting the differences relate the characteristics which are relatable. The table itself does not need to be part of your submitted answer. Fast-Twitch between fiber types within a given characteristic, and what that means to the fiber type. This of course requires you to aracteristic Slow-Twitch Fast-Twitch Oxidative Oxidative Glycolytic Myosin ATPase activity Diameter Contraction duration Ca-ATPase activity (SR) Endurance Metabolism Mitochondria Coloration

Answer 1

The skeletal muscle fibres can be divided into type I slow twitch muscle fibre and type II fast twitch muscle fibres. Type ll muscle fibres are again divided into glycolytic and oxidative depending upon the metabolic pathway.

#Fibre colour:

type l muscle fibre have higher content of myoglobin and capillaries compared to oxidative and glycolytic muscle fibres. Therefore slow twitch fibre are red in colour, oxidative fibres light red or pink in colour and glycolytic white or pale.

#Diameter:

Slow twitch muscle fibre have smallest diameter. Fast twitch oxidative have intermediate diameter and fast twitch glycolytic have largest diameter.

#Endurance, metabolism and mitochondria:

Slow twitch fibres have high content of mitochondria. Oxidative fibres have lesser mitochondria and glycolytic least.

Slow twitch fibres have higher endurance, have aerobic pathway of ATP generation and thus used for long term aerobic trainings. Oxidative fibres have lower endurance due to less myoglobin and dependent on anaerobic oxidative metabolic pathway. Glycolytic fibres have least endurance due to less myoglobin and dependent on glycolytic enzymes and anaerobic pathway.

# myosin ATPase activity and contraction duration:

Slow twitch fibres have low activity level of ATPase and a slower speed of contraction. The oxidative and glycolytic muscle fibres have a higher ATPase activity and higher speed of contraction and thus fatigues easily.