The Effect of Vinegar on a Bone Matrix

Introduction:

Bones are strong and light. They are also somewhat flexible. This experiment helps illustrate what makes a bone strong and how flexible it would be without the strengthening substance.

Hypothesis:

I believe the strength in a bone comes from the minerals. The vinegar will dissolve the minerals, so that the bone will be rubbery and flexible.

Supplies:

An uncooked chicken bone (preferably a wishbone or wing) I used a leg bone

A jar with a lid

Vinegar (preferably white)

Procedure: (from science book module 11.1)

1. Clean the bone of all the meat and tendons. Make it as bare as possible.

2. Allow the bone to dry overnight.
3. The next day, test the bone by trying to gently bend it. Do not use so much force that you break it! Notice the bone bends, a bit but is still mostly rigid.

4. Fill the jar with enough vinegar so that the bone will be fully immersed.

5. Drop the bone in the jar and close the lid.

6. Every day, pull the bone out of the vinegar and test it as you did in step 3.

7. Note the difference you observed.

8. Put the bone back into the vinegar and close the jar again.

9. Continue this process for 7 days or more.

10. Once the 7 days are over, pour the vinegar mixture down the drain, throw the bone       away, and clean up the mess.

Observations:

Day 1: it only bent on one side

Day 2: the solution had changed colors

Day 3: the bone bent on both sides

Day 4: the bone was leaving chunks in the solution

Day 5: I dumped the solution and replaced it with new vinegar

Day 6: the bone was flexible except for the middle

Day 7: the bone was all the way flexible

Results:

The chicken bone was very flexible and rubbery. When I tried to pinch it between my fingers it slipped out from between them. The bone also was very flimsy and couldn't stay up very well. 

Conclusion:  

The results from the experiment confirm my hypothesis; the vinegar ate away the minerals from the bone leaving a flexible core.

Bones consist of cells surrounded by a substance called the bone matrix. The bone matrix is composed of collagen and minerals. The vinegar eats away at the minerals (like calcium) but not the collagen. This process makes the bone rubbery and flexible but, not rigid.

During the experiment the vinegar solution began to look gross so it was replaced with new vinegar in the jar.