Biochemistry Foundations for the MCAT

Amino Acids & Protein Structure

20 standard amino acids classified by side chain:

• Nonpolar: G, A, V, L, I, P, F, W, M
• Polar: S, T, C, Y, N, Q
• Positively charged: K, R, H
• Negatively charged: D, E

Protein Structure:

• Primary: amino acid sequence
• Secondary: α-helix, β-sheet (H-bonds)
• Tertiary: 3D fold (hydrophobic, ionic, disulfide)
• Quaternary: multiple subunits

Enzyme Kinetics

$v = \frac{V_{max}[S]}{K_m + [S]} \quad \text{(Michaelis-Menten)}$