Untitled

Overview of Organic Compounds and Macromolecules

  • Macromolecules: Large organic molecules essential for life, categorized into four major types: carbohydrates, lipids, proteins, and nucleic acids.
  • Importance:
    • Essential for all living processes.
    • Responsible for energy storage, genetic information, and cellular structure.
    • Structural implication: Most macromolecules are polymers made of smaller units called monomers.

Organic Compounds

  • Definition: Compounds containing carbon, typically with carbon-carbon and carbon-hydrogen bonds.
  • Composition: Commonly contain carbon (C), hydrogen (H), oxygen (O), nitrogen (N), phosphorus (P), and sometimes sulfur (S).
  • Common Shapes:
    • Straight Chains: Linear arrangement of carbon atoms.
    • Branched Chains: Carbon atoms arranged with branches.
    • Rings: Carbon atoms arranged in a cyclical structure.

Monomers vs. Polymers

  • Monomers: Basic building blocks (e.g., monosaccharides in carbohydrates, amino acids in proteins).
  • Polymers: Large molecules formed by bonding multiple monomers together (e.g., polysaccharides, proteins).

Chemical Reactions in Biology

Catabolic Reactions

  • Definition: Processes that break down complex molecules into simpler ones, releasing energy.
  • Example: AB→A+BAB \rightarrow A + B

Anabolic Reactions

  • Definition: Processes that build larger molecules from smaller subunits, requiring energy.
  • Example: A+B→ABA + B \rightarrow AB
Hydrolysis
  • Type of catabolic reaction where water is added to break polymer bonds.
  • Reaction: One molecule gets an H ion and another gets an OH ion, facilitating bond breakage.
Dehydration Synthesis
  • An anabolic process where water is removed as bonds between monomers form.
  • Creating a new covalent bond typically results in the loss of a water molecule (1 H and 1 OH).

Types of Macromolecules

Carbohydrates

  • Composition: C, H, O (typically in 1:2:1 ratio in monosaccharides).

  • Function: Short-term energy storage.

  • Types:

    • Monosaccharides: Simple sugars (e.g., glucose, fructose).
    • Disaccharides: Two monosaccharides (e.g., sucrose, lactose).
    • Polysaccharides: Long chains of monosaccharides (e.g., starch, cellulose, glycogen).

  • Polysaccharides in Plants:

    • Cellulose: Provides structure in cell walls; not digestible by animals.
    • Starch: Energy storage form; can be easily digested by enzymes.

  • Polysaccharides in Animals:

    • Glycogen: Stored in liver and muscles, provides energy during fasting and exercise.

Lipids

  • Composition: Mostly C and H, little O.
  • Properties: Nonpolar, not soluble in water.
  • Types: Fats, phospholipids, steroids.
  • Functions:
    • Long-term energy storage.
    • Insulation and protective coatings.

Proteins

  • Composition: C, H, O, N, S.
  • Building Blocks: Amino acids (20 different types).
  • Functions: Extensive (structure, transport, enzymes).
  • Protein Structure Levels:
    • Primary: Linear sequence of amino acids.
    • Secondary: Folding due to hydrogen bonds (e.g., alpha helix, beta sheets).
    • Tertiary: 3D shape formed by interactions between side chains.
    • Quaternary: Structure formed by multiple polypeptide chains.

Nucleic Acids

  • Function: Genetic information storage (DNA & RNA).
  • Composition: C, H, O, N, P.
  • Building Blocks: Nucleotides consisting of a phosphate, a sugar, and a nitrogenous base.
  • Types:
    • DNA: Double helix structure with base pairs (A-T, G-C).
    • RNA: Single-stranded; contains uracil instead of thymine.