You are testing anterior cruciate ligament (ACL) reconstructions with an orthopaedic surgeon. You recorded the following load-deformation data for an experimental femur-ACL-tibia reconstruction in an animal model. The harvested reconstructions were tested in tension until the ligament reached failure. The ACL cross-sectional area was 130 mm2 and the bone-to-bone resting length of the ligament was 2.9 cm. (a) When performing this test, name one thing that had to be done during the testing procedure that would not be done if you were performing a test on a metal specimen.

1. the energy lost to disorder metabolism     -entropy

2. related to or possessing motion potential     -kinetic

3. all of the chemical reactions in an organism required for maintenance of the processes of life entropy     -metabolism

4. possible; ability to go into action or perform work kinetic     -potential

5. the study of energy and its transformations thermodynamics     -thermodynamics

enzyme active site and substrate specificity

enzymes bind with chemical reactants called substrates. there may be one or more substrates for each type of enzyme, depending on the particular chemical reaction. in some reactions, a single-reactant substrate is broken down into multiple products

the solute can move "downhill," from regions of higher to lower concentration, relying on the specificity of the protein carrier to pass through the membrane. this process is called passive transport or facilitated diffusion, and does not require energy.