Experiments performed with biological systems require a buffer that will not interfere with the stability and activities of the biological components. In 1966, Norman Good and his colleagues began a series of investigations that established criteria for new zwitterionic buffers that would be optimal for experimentation with biological systems. These criteria include:

a. pKa between 6 and 8
b. highly water soluble
c. minimally permeable to biological membranes
d. minimal effects of salt concentration
e. minimla effect of temperature on pKa
f. minimal effect of concentration on pKa
g. minimal interaction with metal ions
h. nontoxic
i. high chemical stability
j. minimal absorbance between 240-700 nm

Required:
Write down the property that does meet Good's criteria for biochemical buffers.

What are the choices?

For cyclohexane compounds drawn in a chair conformation:   -axial bonds are vertical  -equatorial bonds are parallel to two bonds within the ring.  thus, as i assume the chair conformation is drawn:   -the x group is in an axial position, as are the five other vertical bonds.  -three axial bonds are on the top face of the ring  -the other three axial bonds are on the bottom face  the position of the second substituent on each ring carbon is equatorial.  gauche groups must be on an adjacent carbon such as carbon 6 and carbon 2, and also gauche groups are rotated by 60 degrees relative to each other.  drawing the newman projections for c1–c2 and c1–c6 aids in visualizing the groups that are gauche to the y group on c1.  click this link and watch some academic videos that may you more understand the topic 

The mass has escaped into a gas which you can not see so the law stays true.