Which term best describes the relatively small portion of the enzyme that is directly involved in the biochemical reaction being catalyzed?

The three most common forms of chocolate in the United States are Dark Chocolate, Milk Chocolate and White Chocolate.  The following image shows the active ingredients in each of these types of chocolate.  Which of these active ingredients represents the nonpolar molecule?    

The reactant in an enzyme-catalyzed reaction is the

What is the molar concentration (M) of a solution that contains 10.0 g C6H12O6 in 500. mL solution? Molar mass: C6H12O6 = 180.2 g/mol

What is the correct atomic symbol for the ion that contains 11 protons, 10 electrons and 13 neutrons (use the periodic table below)? A. K+ B. Na+ C. Mg2+ D. F-     

The chemical formula for sodium phosphate is Na3PO4.  What is the charge on the phosphate ion?

Below is an image of a cellular membrane.  Which part of the membrane is polar and which part is nonpolar?   

What is the atomic mass of the ion in the previous question if it has 11 protons, 10 electrons and 13 neutrons?

What mass (in grams) of ethanol can fill a 200.0 mL beaker if the density of ethanol is 0.789 g/mL?  

Dr. Maloney has asked you to make a solution of Hydrochloric acid (HCl) to be used in lab this week.  She says the class needs 500 mL of 2.5 M HCl.  After going to the stock room, you find a stock solution of HCl in the acid cabinet with a concentration of 12.0 M.  In order to prepare the dilution for class, you need to add [HCl] of the HCl stock solution to [water] of water.