PC1001 Lecture Notes - Lecture 18: Anaerobic Glycolysis, Myocyte, Glycolysis
Document Summary
Colour determined by the amount of myoglobin, mitochondria and capillaries. More myoglobin (an oxygen- storing reddish pigment similar to rbc haemoglobin). Speed of contraction - determined by speed at which atpases split atp. The two types of fibres are slow and fast based on atp-forming pathways: Are smaller fibres with fewer myofibrils => less power. Have high capillary and large numbers of mitochondria to support high levels of oxidative metabolism. Contain large amounts of myoglobin, which gives the muscle a reddish appearance. Larger for great strength of contraction - more myofibrils. Extensive sarcoplasmic reticulum for rapid release of ca2+. Large amounts of glycolytic enzymes for rapid release of energy. Lower capillary, fewer mitochondria (because oxidative metabolism is secondary) and deficit of myoglobin gives it a whitish appearance. More easily fatigable (glycogen reserves used rapidly, and lactic acid production). Most muscles are composed of a mixture of fast and slow muscle fibres. Proportions vary with the usual action of the muscle:
