White vs. Dark Meat

Continuing with the Thanksgiving theme, today I think you should know the biological difference between white and dark meat in turkey.

Everyone knows that turkeys cannot fly (well, they can for very short distances – nothing crazy) and they rely on their legs to get around. It’s also kind of common sense that these are not exactly the most petite members of the bird family. Lugging all of that weight around requires strong leg and thigh muscles. These and other strong muscles are comprised of slow-twitch fibers. Slow twitch fibers are associated with muscles that need to work constantly for long durations of time. To sustain these muscles, more myoglobin (a muscles version of hemoglobin) is needed.

Sidenote: myoglobin has a very high affinity to oxygen and is therefore perfectly suited to carry oxygen to the muscles. Muscles need oxygen to work. Oh, I totes will do a post about how oxygen binds to hemoglobin in the future! Anyhow, back to dark meat…

More myoglobin (and more blood vessels to deliver the myoglobin) makes those muscles much darker. On the other hand, fast-twitch muscles, such as in the breast and wings, are lighter because they do not need such a large supply of oxygen from the myoglobin because they only perform short spurts of energy – then they can rest.

So there you go…

And so you know, I don’t work for the rest of the week and that means there will probably not be another update until Monday. Have a great Thanksgiving!