Bone dissection

Chemical Composition of Bone

Bone is a very hard material which is capable of bearing a large amount of weight and resisting tension and twisting forces. Therefore, this material is both flexible and hard. The hardness of bone is due to calcium deposits in the matrix while the flexibility comes from the organic material of the matrix. We can illustrate these facts by treating two bone samples by two different methods: 1. Soaking a bone in vinegar (dilute acetic acid) removes calcium and other minerals from the bone. Samples treated in this manner remain flexible but lose their hardness. 2. Baking a bone chars the organic material in the bone matrix leaving the bone very brittle. In this experiment we will treat two bone samples as described above and observe the changes that occur. Materials Note: To complete both experiments, you will need two raw chicken bones. Use a separate bone for each experiment.
Fresh, raw chicken leg bones
Approximately 1 gallon vinegar
Oven for baking bones
Containers for holding bones (quart jar and heatproof dish) Procedure 1. Remove all muscle and cartilage from the bones.
2. Removal of minerals:
a. Place the bone in a large container and fill the container with vinegar or acetic acid.
b. Soak the bone for approximately one week changing the vinegar several times.
c. When the bone becomes flexible, remove it from the vinegar and rinse thoroughly in water.
3. Removal of organic materials a. Place the bone in a heatproof container and bake for two hours at 350F. b. Remove from the oven and cool. Results 1. Bone soaked in vinegar a. Try to bend the bone. b What did you observe? Soaking a bone in a vinegar (dilate acetic acid) removes calcium and other minerals from the bone. 2. Baked Bone a. Try to bend the bone. Smash the bone by stepping on it. b. What did you observe? Baking a bone chars the organic materials in the bone matrix leaving the bone very brittle. Questions 1. What material is responsible for hardness of bone? Calcium

2. What material accounts for flexibility of bone? Organic materials 3. From this experiment we can conclude calcium_____ is responsible for the hardness of bone while _organic materials________ is responsible for flexibility.
4. Which bone would resemble the bones of a child with rickets?

Note: Chicken may be contaminated with Salmonella. Wear gloves when possible during handling and wash hands thoroughly at the conclusion of your work.