AP Biology Unit 1 Review

Introduction

• Presenter: Glenn Wenel (Mr. W)
  • Recently retired AP Bio teacher with 20 years of experience.
  • Developed curriculum used by thousands of students and teachers.
• Purpose: Review of AP Biology Unit 1 to prepare for the AP Bio Exam.

Topics Covered

1. Chemistry of Water and Hydrogen Bonding
2. Carbon, The Elements of Life, and Functional Groups
3. Monomers and Polymers
4. Four Big Biological Molecules: Carbohydrates, Lipids, Proteins, Nucleic Acids

Water and Hydrogen Bonding

• Hydrogen Bonding:

  • Water is a polar molecule with partial negative (oxygen) and positive (hydrogen) regions.
  • Hydrogen bonds are weak intermolecular bonds, essential for biological structures like DNA and proteins.

• Properties of Water:

  • Cohesion: Attraction between water molecules; contributes to high heat of vaporization, specific heat, and surface tension.
  • Adhesion: Water sticking to other substances (e.g., cellulose in plants).
  • Surface Tension: Water molecules create a net that supports small objects.

Acidity, Basicity, and pH

• Acidic Solutions: More hydrogen ions, pH < 7.
• Basic Solutions: More hydroxide ions, pH > 7.
• pH is a foundational concept, not directly tested on the AP exam.

Elements of Life

• Key Elements: Carbon, Hydrogen, Nitrogen, Oxygen, Phosphorus, Sulfur (CHNOPS).
• Carbon's central role in life; hydrogen's role in energy exchange and acidity.

Monomers and Polymers

• Monomers: Building blocks of carbohydrates, proteins, nucleic acids.
• Polymers: Large molecules with specific shapes formed by monomers.
• Processes:
  • Dehydration Synthesis: Builds polymers by removing water.
  • Hydrolysis: Breaks polymers by adding water.

Functional Groups

• Importance for understanding molecular interactions in biology.
• Examples: Phosphate, methyl, hydroxyl, carbonyl, carboxyl, amino, sulfhydryl, acetyl groups.

Biological Molecules

Carbohydrates

• Types: Monosaccharides (glucose), disaccharides (lactose), polysaccharides (starch, glycogen, cellulose).
• Functions:
  • Energy storage: Starch in plants, glycogen in animals.
  • Structural: Cellulose in plants, not digestible by most animals.
  • Lactose Intolerance: Genetic adaptation in some human populations allowing lactase production into adulthood.

Lipids

• Characteristics: Non-polar, hydrophobic, not composed of repeating monomers.
• Types and Functions:
  • Fats: Energy storage.
  • Waxes: Waterproofing.
  • Phospholipids: Cell membranes.
  • Steroids: Signaling.

Proteins

• Monomers: Amino acids with a central carbon, amino group, carboxy group, variable R group.
• Structure Levels:
  • Primary: Linear amino acid sequence.
  • Secondary: Hydrogen bonding forms alpha helices, beta sheets.
  • Tertiary: Interactions among R groups form 3D structure.
  • Quaternary: Multiple polypeptides form a functional protein.
• Example: Hemoglobin's role in sickle cell disease.

Nucleic Acids

• Importance: Genetic material (DNA), information transfer (RNA).
• Structure:
  • DNA: Double-stranded, complementary base pairing (A-T, G-C), anti-parallel orientation.
  • RNA: Single-stranded, versatile, catalytic functions.
• Nucleotides: Composed of a sugar, phosphate group, and nitrogenous base.

Summary

• Unit review covers core concepts for mastering Unit 1 in AP Biology.
• Encouragement to use resources like LearnBiology.com for effective study and exam preparation.