What holds a protein in its tertiary structure?

What is the feature marked by the yellow dot on the image below? Note: it is also outlined by a red circle to help you locate it.

Calculate the moles of HBr if `x` mL of `y` M of it is used in this reaction. Report you answer with 4 places after the decimal.

Water molecules form ________ ions when they associate with a hydrogen ion.

Steroids are derived from cholesterol.

The resting membrane potential is closest to the equilibrium potential for ________.

Proteins that are partially embedded on one side of the plasma membrane are ________.

What structures are used for direct cell to cell signaling?

Which two muscles of the eye allow one to look straight up from the primary position?

What type of cell signaling uses neurotransmitters to innervate its target organ?