Red and White Muscles

Skeletal muscles can also be classified into red and white muscle, based on how much of a particular red pigment they contain. Red muscles contain a very high amount of myoglobin, while white muscles contain very little of this pigment.

Myoglobin is an iron-containing, red-coloured pigment found only in muscle tissue. It consists of one haeme group attached to a single polypeptide chain, and — unlike haemoglobin, which can carry four oxygen molecules — each myoglobin molecule can bind and carry just one molecule of oxygen. …