Biomolecules - Formula Sheet

Key Formulas and Mathematical Relations

1. Optical Isomers of Carbohydrates

Formula:

Number of Optical Isomers = 2^n

Symbol Definitions:

• n: The total number of asymmetric (chiral) carbon atoms present in the carbohydrate molecule.

2. Amino Acid Isoelectric State

Conditions and Net Charges:

• At pH less than pI: Net Charge = +1 (exists as cation)
• At pH equal to pI: Net Charge = 0 (exists as neutral zwitterion)
• At pH greater than pI: Net Charge = -1 (exists as anion)

Symbol Definitions:

• pH: The negative logarithm of hydrogen ion concentration of the solution.
• pI: The isoelectric point, which is the specific pH at which the amino acid has no net charge.

3. Complementary Base Ratios (Chargaff's Rules)

Mathematical Relations:

A = T and G = C

Therefore: (A + G) / (T + C) = 1

Symbol Definitions:

• A: Mole fraction of Adenine.
• T: Mole fraction of Thymine.
• G: Mole fraction of Guanine.
• C: Mole fraction of Cytosine.