AP Biology 1.4 Carbohydrates Study Notes - New Syllabus Effective 2025
AP Biology 1.4 Carbohydrates Study Notes- New syllabus
AP Biology 1.4 Carbohydrates Study Notes – AP Biology – per latest AP Biology Syllabus.
LEARNING OBJECTIVE
Describe the structure and function of carbohydrates.
Key Concepts:
- Complex Carbohydrates
1.4.A – Carbohydrates: Structure & Function
🧱 Structure of Carbohydrates:
- Made of: Carbon (C), Hydrogen (H), Oxygen (O)
- Basic ratio: 1C: 2H: 1O (like C₆H₁₂O₆)
Monomer = Monosaccharide (simple sugar)
- e.g., Glucose, Fructose, Galactose
Disaccharides = 2 monosaccharides joined by dehydration synthesis
- e.g., Sucrose = Glucose + Fructose
Polysaccharides = long chains of monosaccharides
- e.g., Starch, Glycogen, Cellulose, Chitin
⚙️ Function of Carbohydrates:
| Type | Function | Found In |
|---|---|---|
| Starch | Energy storage in plants | Potatoes, grains |
| Glycogen | Energy storage in animals | Liver, muscles |
| Cellulose | Structural support in plant cell walls | Vegetables, plant fibers |
| Chitin | Structural support in fungi & arthropods | Fungal walls, insect exoskeletons |
🧪 Key Features:
- Quick energy source (especially glucose)
- Stored energy (starch/glycogen)
- Some carbs give structure, not energy (like cellulose)
- Formed via: Dehydration synthesis
- Broken down via: Hydrolysis
🧠 Important Terms to Know:
- Monosaccharide = 1 sugar unit
- Disaccharide = 2 sugar units
- Polysaccharide = many sugar units
- Glycosidic linkage = bond between sugar monomers
1.4.A – Carbohydrates: Structure & Function
🧱 What are carbohydrates made of?
- Monosaccharides (simple sugars) are the monomers of carbohydrates.
- Common examples: Glucose, fructose, galactose
- General formula: C₆H₁₂O₆
🔗 How are they built?
- Monosaccharides link through covalent bonds (glycosidic bonds) using dehydration synthesis.
- Many monosaccharides linked together form polysaccharides (complex carbohydrates).
- Polysaccharides can be:
- Linear (straight)
- Branched (tree-like)
🍚 Types of Carbohydrates:
| Type | Structure | Function |
|---|---|---|
| Monosaccharides | Single sugar unit | Quick energy |
| Disaccharides | Two monosaccharides (e.g. sucrose = glucose + fructose) | Transport form of sugar in plants |
| Polysaccharides | Long chains of monosaccharides | Energy storage or structural support |
⚙️ Major Functions of Carbohydrates:
- Energy Source – Glucose is the primary fuel for cells.
- Energy Storage:
- Plants → Starch
- Animals → Glycogen
- Structure:
- Plants → Cellulose (cell walls)
- Fungi & insects → Chitin (exoskeleton)