Chapter 3 Inorganic Vs Organic Compounds

Inorganic vs Organic Compounds

• Importance in body's structure and function

Chemical Constituents of Cells

• Inorganic Compounds

  • Usually lack carbon and are structurally simple

  • Examples: water, oxygen, carbon dioxide, salts, acids, and bases

• Organic Compounds

  • Contain carbon and hydrogen as primary elements linked by covalent bonds

  • Often large and complex structures

Water's Role in Chemistry

• Water as a polar molecule

  • Oxygen is more electronegative than hydrogen

  • Electrons spend more time near the oxygen nucleus than hydrogen nucleus

Hydrogen Bonds

• Formation

  • Occurs when a hydrogen atom covalently bonded to one electronegative atom is also attracted to another

  • Do not form new molecules, but link existing ones

  • Affect the properties of those molecules

Properties of Water from H-bonding

• Water is a liquid at room temperature

• Cohesive properties

  • Water molecules are cohesive

  • Fills vessels due to cohesion

• High heat capacity

  • Water can absorb and carry heat away as vapor

• Ice is less dense than liquid water

• Effective lubricant and universal solvent for polar molecules

  • Hydrophilic and hydrophobic interactions

Water as a Solvent

• Polar nature allows water to form hydrogen bonds easily

• Examples:

  • Glucose and NaCl dissolve in water, surrounded by hydration shells

Salts

• Formed when ions bind via ionic bonds

• Dissociation in water yields ions excluding H+ or OH−

• Electrolytes can conduct electricity

Acids and Bases

• Acids

  • Release hydrogen ions (H+) in solution

• Bases

  • Release hydroxyl ions (OH−) or accept H+ in solution

Organic Compounds

• Contain carbon and hydrogen

• Large and complex structures

• Difference between monomers and polymers

Water in Chemical Reactions

• Dehydration Synthesis

  • Monomers joined by removing OH from one and H from another, forming water

• Hydrolysis

  • Monomers released by adding water, adding OH to one and H to another

  • Both processes involve covalent bonds

Types of Organic Molecules

• Four Main Types:

  • 1. Carbohydrates

  • 2. Lipids

  • 3. Proteins

  • 4. Nucleic Acids

Carbohydrates

• Composition:

  • Diverse group formed from C, H, and O

  • Typical ratio: 1:2:1, e.g., glucose (C6H12O6)

• Function:

  • Main source of energy

• Examples of Simple Carbs:

  • Glucose, fructose

Diversity of Carbohydrates

• Monosaccharides

  • Basic units include glucose, fructose, galactose

• Disaccharides

  • Formed through dehydration synthesis

• Polysaccharides

  • Long chains, energy storage forms in plants and animals (starch in plants, glycogen in animals)

  • Digestive properties vary

Lipids

• Composed mainly of C, H, and O

• Example Lipids:

  • Butter, cheese, oil, wax

• Functions:

  • Energy storage, structural components of membranes, insulation, protection, signaling molecules

  • Fat-soluble vitamins require lipids for absorption

Fatty Acids and Triglycerides

• Saturation Levels:

  • Saturated: straight chains

  • Unsaturated: kinked chains

• Triglycerides:

  • Stored as fat deposits and provide energy

  • Help with insulation and organ protection

Phospholipids

• Structural lipids that form cell membranes

  • Comprise hydrophilic heads and hydrophobic tails

Steroids

• Type of lipid with structure of four fused carbon rings

  • Example: cholesterol, precursor to steroid hormones

Proteins

• Most abundant organic molecules in the human body

• Functions of Proteins:

  • Support, movement, transport, metabolic regulation, coordination, control, and defense

• Composed of amino acids linked by peptide bonds

• Proteins are polymers made from amino acid monomers

Protein Structure

• Levels of Structure:

  • Primary: amino acid sequence

  • Secondary: alpha-helix or beta-pleated sheet due to H-bonding

  • Tertiary: 3D shape from further folding

  • Quaternary: interaction between multiple polypeptide chains

Enzymes

• Type of protein that catalyzes chemical reactions

• Speed up reactions by orienting colliding molecules

Protein Denaturation

• Changes in the environment (heat, pH) can alter protein structure and function

• Cooking an egg changes its protein structure significantly

Nucleic Acids

• Organic molecules that store and process information

  • Two classes:

  • DNA: encodes instructions for protein synthesis

  • RNA: helps in building proteins using DNA information

DNA Structure

• Two chains of nucleotides forming a double helix

• Base pairing rules: A-T, G-C

Function of DNA and RNA

• DNA provides genetic blueprint

• RNA carries genetic instructions for protein synthesis

ATP

• Cells require energy for functions

• ATP is the main energy source, breaking down releases energy to drive processes