Nucleic Acids: Sugars & Bases - MCAT Highlights

Recognizing the components: phosphate group, nitrogenous base, and sugar. Understanding that deoxyribose and ribose differ by a hydroxyl at the 2’ position. Classification into purines (A, G) and pyrimidines (C, T, U). Knowing which bases are unique to DNA or RNA (T for DNA, U for RNA). Application of mnemonics: "CUT the Py" and "Pure As Gold". A pairs with T (DNA) or U (RNA); G pairs with C. Base pairing: A–T/U has 2 hydrogen bonds; G–C has 3 hydrogen bonds. Implication for DNA melting temperature and stability. Quantitative relationships between bases. Used in MCAT-style calculations and interpretation of base percentages. 5' to 3' strand directionality, sugar carbon prime notation. Important for understanding transcription, replication, and PCR. Chemical nature of base interactions. Stability implications in molecular biology and lab applications. Drawing or identifying base and sugar structures (seen in MCAT passages/figures). Structural effects on function (e.g., methylation in thymine). Nucleic Acids: Sugars & Bases - MCAT Biology - Question 1 Nucleic Acids: Sugars & Bases - MCAT Biology - Question 2 Nucleic Acids: Sugars & Bases - MCAT Biology - Question 3 Nucleic Acids: Sugars & Bases - MCAT Biology - Question 4 Nucleic Acids: Sugars & Bases - MCAT Biology - Question 5