Chemistry for Physiology

All enzymes are proteins. Carbohydrates should be the major energy source. Choice D lists the fat soluble vitamins.

Gastric juice has a pH of about 1.5. The solution in choice D has a pH of 5 (= negative log of 10−⁵) .

The number of atoms, written as a subscript, immediately follows the symbol for the element and C, H, O are the symbols for carbon, hydrogen and oxygen, respectively.

A “hydrogen ion” H⁺ is a bare proton which, if it freely exists, would attach to a water molecule to form the hydronium ion (H₃O⁺). So choice D is a better answer than Choice B.

As the molar mass of urea is 60 g, this means that 1 mol of urea has a mass of 60 g. Now 450 mmol is LESS than 1 mol, so the number must be less than 60 g. By numbers: 450 mmol × 60 g/mol = 0.45 × 60 = 27 g

Hydrocarbon means hydrogen combined with carbon.

Non-metals share electrons when they react with each other (rather than losing or gaining), hence the prefix “co-“.

5% means 5 g per 100 ml. So in 300 ml there would be 3 × 5 g = 15 g infused.

Having a different number of neutrons (while having the same number of protons) is what defines them to be isotopes

0.9% = 0.9% = 0.9 per hundred = 0.9 g per 100 ml of solution.