BIO 152 Lecture Notes; Biomolecules Essential for A&P

I. The Biomolecules

A. Important classes of biomolecules

  1. Carbohydrates

    • Chiefly used for energy production

  2. Lipids (fats)

    • Chiefly used for energy storage

  3. Proteins

    • Chiefly used for structure

  4. Nucleic acids

    • Chiefly used for information storage

  5. High energy molecules

    • Example: ATP (adenosine triphosphate)

B. Characteristics of biological molecules

  1. All are polymers made up of monomers

    • Polymer: Large chain-like structure made of repeating units; e.g., protein

    • Monomer: Single unit used to make up polymers; e.g., amino acid

  2. All are organic molecules

  3. All built on carbon skeletons

    • Different types of carbon skeletons:

      • Straight chain

      • Branched chain

      • Ring structures

  4. All contain functional groups

    • Functional group: Group of atoms with a consistent function

    • Common groups include:

      • Carboxyl group (acidic)

      • Amino group (basic)

      • Nonpolar groups

      • Polar groups

C. Carbohydrates

  1. Basic formula: Cₙ(H₂O)ₙ

    • Example: Glucose (C₆H₁₂O₆)

  2. Functions:

    • Energy source

    • Energy storage

    • Structural role

  3. Classification:

    • Monosaccharides

    • Disaccharides

    • Polysaccharides

  4. Important examples

    • Pentoses (Ribose, Deoxyribose)

    • Hexoses (Glucose, Fructose, Galactose)

D. Lipids

  1. Functions:

    • Energy storage (1g lipid = 9 kcal)

    • Energy source

    • Thermal insulation

    • Protection of vital organs

    • Neural impulse transmission

    • Tissue structure

  2. Components:

    • One molecule of glycerol

    • Three fatty acids

    • Classification of fatty acids: saturated, unsaturated (mono- and polyunsaturated)

E. Proteins

  1. Functions:

    • Structural, contractile, defense, carrier, regulatory roles

    • Energy source

    • Fluid balance, genetic expression

  2. Composition:

    • Amino acids joined by dehydration synthesis

  3. Structure:

    • Primary, secondary, tertiary, and quaternary levels

F. Nucleic acids

  1. Function:

    • Information molecules (DNA, RNA)

  2. Composition:

    • Nucleotides (nitrogen base, pentose sugar, phosphate group)

    • Types: Deoxyribonucleotides (DNA) and ribonucleotides (RNA)

G. Energy molecules

  1. Primary example: ATP

    • Function: Used for cellular energy

    • Composition: Adenine, ribose, three phosphates

    • ATP-ADP cycle: Breakdown and synthesis of ATP based on energy needs

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