Chemistry for Physiology

A ketone has a “carbonyl” functional group (C double bonded to O), while the carbon atom of the carbonyl group is also bonded to two other carbon atoms (that is, is attached to two radicals). Choice C is incorrect as the O is single bonded to the carbon(s). Choice A is incorrect as the NH group is not a radical.

A millimole is one thousandth (or 0.001) of a mole.1 mmol = 10−³ × (6 × 10²³) = 6 × 10²⁰ particles

A buffer will resist change to its pH. But pH does alter very slightly as the basic component destroys the added acid and in the process becomes its cognate partner. This changes the ratio of the two components of the buffer slightly and hence the pH.

The definition should include “water”, movement through an SP membrane and direction of water flow from more dilute solution into the solution of higher concentration.

A polypeptide is several amino acids joined together. Hence the element nitrogen must be present.

Ionic compounds are formed when metal atoms react with non-metal atoms. The structures that form are not molecular.

While diffusion can occur through a membrane, its presence is not required in order to define diffusion.

Multiply the number of atoms of each element (H, C, N, O) in the formula by the element’s atomic weight to get mass of a mole. Hence: (4 × 1) + (1 × 12) + (2 × 14) + (1 × 16) = 4 + 12 + 28 + 16 = 60 g.

Carbon has four valence electrons and “would like” a share of four more to fill its outer shell. This is achieved by four covalent bonds, where a double bond counts as two covalent bonds.

A metal element loses an electron in chemical reactions so that its number of protons outnumber the electrons which leaves it with a positive charge. Choice B, while being a positive ion, is a compound, not an element.