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

      1. Lipids

      1. Proteins

      1. 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