Science Buddies: "Ask an Expert"

My daughter (6th grade), is doing a project on whether or not the acid in coca cola affects meat and, if it does whether or not it affects red meat and white meat differently. Her experiment, which is ongoing, involves submerging steak, chicken and white fish in coca cola and weighing it daily to determine whether or not the coke is deteriorating it and if so, is there a difference in the rate at which the various meats deteriorate. She is trying to find out the biological difference between the meat from steak versus chicken and fish as part of her background research, but isn't having much luck. Any direction would be appreciated!

A good place to start is to look up 'slow oxidative fibers' and 'fast glycolytic fibers' on your favorite search engine. Most of the differences in 'meat' are actually due to differences in the proportions of fibers! However, there are also some structural differences between, say, fish meat and steak. Try looking up 'fish muscles' or just 'muscles' to help you get started on that. You might also want to look up 'myoglobin', since it is an important component in what we perceive to be the 'color' of meat.

Good luck!

Red meat is meat that contains more slow twitch fibers, which are for long-term use like running a marathon. An example in a chicken is the leg because they walk around all day. They appear red because they need a larger blood supply for oxygen and waste exchange. Red muscles use more aerobic metabolism (with oxygen).
White meat is meat that contains more fast twitch fibers, which have short-term contractions like in sprinting. In a chicken, the breast is white meat because when they are disturbed, they have to quickly and briefly flap their wings to fly. This type of muscle uses more anaerobic metabolism, like glycolysis, which is responsible for muscle fatigue and lactic acid.

Oh, and by the way, myoglobin is a pigment protein (red) that carries oxygen. It is present in especially large amounts in the slow fibers in red meat.