Tutor profile: Sarah S.

What does it mean if a molecule is chiral?

A chiral molecule is one that does not have a superimposable mirror image. It also has the ability to rotate light in one particular direction. In organic chemistry, chiral centers are often carbon atoms with bonds to four distinct groups.

What is the difference between modulation and extended tonicization?

Modulation is more permanent than extended tonicization. If a piece modulates, it is expected to remain in that new key for at least one phrase, typically, in order to establish the new key. However, if a piece exhibits extended tonicization, that "new key" might only be present for a few notes and, although the new key is exhibited in the short term, it is not established and the tonal center of the music does not change.

In the peripheral tissue of an animal standing outside in the snow, how does the membrane fluidity in the peripheral tissues compare with that in the core immediately after stepping into the cold versus after two hours?

Heat increases membrane fluidity. Therefore, immediately after the animal steps out into the cold, the membrane fluidity in the periphery, where the body is more susceptible to temperature changes, would be less than that in the core, where the body retains the majority of its heat. However, membrane fluidity is also homeostatic, meaning that over time membranes and their components adapt to return to a steady state. That means that after two hours, the membrane fluidity would be similar between the two regions since the membranes in the peripheral tissue would have had time to adapt to the colder temperatures.