Notes on Organic and Inorganic Compounds
Learning Objectives
- Recognize the composition and properties typical of organic and inorganic compounds.
Organic Compounds
- Definition: Organic chemistry studies the structure, properties, composition, reactions, and preparation of carbon-containing compounds.
- Composition:
- Most organic compounds contain carbon (C) and hydrogen (H).
- May also include nitrogen (N), oxygen (O), halogens, phosphorus (P), silicon (Si), sulfur (S).
- Properties of Organic Compounds:
- Key substances making up living organisms.
- Examples include sugars, proteins, lipids, and nucleic acids.
Inorganic Compounds
- Definition: Inorganic compounds are substances that do not contain carbon.
- These compounds are important in various biological processes but do not primarily form the structure of living things.
Comparison of Organic and Inorganic Compounds
| Property | Organic Compounds | Inorganic Compounds |
|---|
| Melting Points | Low (-95°C for Hexane) | High (801°C for NaCl) |
| Boiling Points | Low (69°C for Hexane) | High (1413°C for NaCl) |
| Solubility | Low in water; high in nonpolar solvents | Soluble in water; insoluble in nonpolar solvents |
| Flammability | Highly flammable | Non-flammable |
| Electrical Conductivity | Does not conduct electricity | Conductive in aqueous solutions |
| Bonding | Exhibits covalent bonds | Exhibits ionic bonding |
Types of Organic Compounds
- Carbohydrates
- Main use: Immediate energy
- Composed of C, H, and O; includes monosaccharides, disaccharides, oligosaccharides, and polysaccharides.
- Lipids
- Main purpose: Long-term energy storage
- Composed of glycerol and fatty acid chains.
- Proteins
- Main uses: Structural (muscle fibers), enzymes (catalysts), and energy (in starvation).
- Composed of amino acids; linked by peptide bonds.
- Nucleic Acids
- Main use: Store and carry genetic information
- Composed of nucleotides.
- Formation:
- Through dehydration synthesis (condensation), where monomers link by releasing water.
- Breakdown:
- Through hydrolysis, where adding a water molecule breaks down complex molecules into simpler units.
Carbohydrates Classification
Types of Carbohydrates
- Simple:
- Monosaccharides: Single sugar units (e.g., glucose)
- Disaccharides: Two sugar units (e.g., sucrose)
- Complex:
- Oligosaccharides: 3-10 sugar units (e.g., raffinose)
- Polysaccharides: 10+ sugar units (e.g., starch, cellulose)
Properties of Water
- Polarity: Water is a polar molecule, leading to hydrogen bonding.
- Cohesion: Water molecules stick together, creating surface tension.
- Adhesion: Water can stick to other substances, facilitating capillary action in plants.
- High Specific Heat: Water resists temperature changes, stabilizing organisms' environments.
- Less Dense as Solid: Ice floats on water; organisms can survive beneath frozen surfaces.
- High Solubility: Water acts as a universal solvent, aiding in nutrient transport in biological systems.
Acids and Bases
- Acids: Form hydrogen ions (H+) in water.
- Bases: Form hydroxide ions (OH-) in water.
- pH Scale: Measures acidity or alkalinity.
- pH < 7: Acidic
- pH = 7: Neutral
- pH > 7: Basic
Importance of Oxygen and Salts
- Oxygen (O2): Essential for cellular respiration; needed for ATP production.
- Salts: Dissolve easily in water, forming ions that are critical for metabolic processes, acting as electrolytes.