AP Biology Unit 1 Review: Chemistry of Life

Introduction

• Purpose: Review for AP Biology focusing on Unit 1
• Main Topics: Chemistry of life, water properties, elements, molecules, and macromolecules

Important Properties of Water

• Significance: Water makes up 70% of the human body
• Hydrogen Bonding:
  • Structure: Water molecule with oxygen and two hydrogens
  • Polarity: Polar bonds with a negative charge on oxygen and positive on hydrogens
  • Cohesion: Attraction to itself (water molecules)
  • Adhesion: Attraction to other charged substances
• Hydrophilic vs Hydrophobic:
  • Hydrophilic: Likes water, dissolves in water (polar substances)
  • Hydrophobic: Doesn't dissolve in water (non-polar, like oils)
• Heat Properties:
  • High Heat of Vaporization: Takes a lot of energy to boil
  • High Specific Heat: Hard to change temperature
• Density: Water is denser than ice, allowing ice to float

Elements and Atoms

• Basic Definitions:
  • Elements: Different substances on the periodic table
  • Atoms: Basic building blocks of elements
  • Subatomic Particles: Protons (+), Neutrons (neutral), Electrons (-)
• Carbon:
  • Importance: Backbone of organic chemistry
  • Forms strong bonds with other carbons

Functional Groups

• Hydroxyl (OH): Forms hydrogen bonds (Alcohols)
• Methyl (CH3): Hydrophobic
• Sulfhydryl (SH): Forms disulfide bridges
• Phosphate (PO4): In DNA, energy transfer
• Carbonyl (CO): Defines sugars
• Carboxyl (COOH): Acidic properties
• Amino (NH2): Basic properties, found in amino acids

Types of Bonds

• Ionic Bonds: Attraction between ions (e.g., Sodium and Chlorine)
• Covalent Bonds: Sharing of electron pairs (polar and non-polar)
• Intermolecular Forces (IMF):
  • London Dispersion: Random electron movement
  • Hydrogen Bonding: Strong polar attraction

Macromolecules

• Carbohydrates:
  • Types: Monosaccharides, Disaccharides, Polysaccharides
  • Examples: Glycogen and Starch (Alpha bonds), Cellulose and Chitin (Beta bonds)
• Proteins:
  • Amino Acids: 20 types, connected by dehydration synthesis
  • Functions: Enzymes and cellular functions
• Lipids:
  • Structure: Glycerol and fatty acids
  • Phospholipids: Hydrophilic heads and hydrophobic tails (cell membranes)
  • Types: Saturated, Unsaturated, Trans Fats
• Nucleic Acids:
  • Structure: Nucleotides (Ribose sugar, Nitrogenous base, Phosphate group)
  • DNA vs RNA:
    • DNA: Double-stranded, ATCG
    • RNA: Single-stranded, AUCG
  • Purines vs Pyrimidines:
    • Purines: Adenine, Guanine
    • Pyrimidines: Uracil, Cytosine, Thymine

Conclusion

• Coverage: Chemistry of life, key concepts for AP Biology
• Next Steps: Continue with AP review and preparation

Note: These notes provide a high-level summary of key concepts in Unit 1 for AP Biology focused on the chemistry of life, including the properties of water, and the nature of elements, functional groups, bonding, and macromolecules.