Class: BE210
Group: W3
Members: FACILITATOR David Frerichs, TIME & TASK KEEPER Anna Marie Lipski, SCRIBE Alice Wu,  PRESENTER Christopher Hack
Date: 5/11/00
Full Text

Abstract:

The rate of calcium extraction from three chicken femurs was determined by varying surface areas of a whole bone filled with wax, a longitudinally halved bone, and a ground bone.   Each bone was suspended in a beaker that was filled with 900mL of 1M HCl solution.  Samples were taken from the beakers for a period of 4.5 hours at 15 minute intervals and then twice daily for four days afterwards.  The samples were then analyzed by atomic absorption spectrophotometry.  Results were analyzed by fitting a second order polynomial to the calcium released versus time graph.  The results showed that the ground bone released the most calcium, 69.92% the estimated maximum calcium available, as opposed to 61.24% for the halved bone and 52.14% for the whole bone.  Experimental data also revealed that the original hypothesis of the experiment was false - surface area was not the only determining factor in the rate of calcium extraction from a chicken femur.  The halved bone had 10% greater surface area than the whole bone, but a calcium extraction rate that was 290% greater.  It was hypothesized that the penetration distance of each bone, rather than the surface area, was the determining factor in the extraction rate.  The experimental data fell within ? 12% of the values predicted by the equation R ? (Do*SA)/??, where R is the rate of extraction, Do is the diffusion constant, SA is the surface area, and ?? is the average diffusion distance.  This showed that the thickness of the bone, or effective diffusion distance of the HCl solution, is a significant in the calcium extraction rate of chicken femur bone.  Further experimentation would be necessary to determine the exact relationship between the thickness of the bone, surface area, and the rate of calcium extraction.