Chapter 3 part 3

  • Differences Between Organic and Inorganic Molecules:

    • Elemental Composition: Organic molecules always contain carbon and hydrogen.

    • Structural Backbone: They have a chain of carbon atoms linked with hydrogen.

    • Bonding Type: Held together by covalent bonds, in contrast to inorganic compounds that use ionic bonds.

    • Molecular Size: Generally larger than inorganic molecules.

    • Biological Association: Mostly found in living things.

  • Major Categories of Organic Molecules:

    • Carbohydrates (or "carbs")

    • Proteins

    • Lipids (like fats)

    • Nucleotides

  • Functional Groups in Organic Molecules:

    • Functional groups affect how molecules react.

    • Hydroxy Group: Made of oxygen and hydrogen (OHOH).

    • Carboxyl Group: Contains carbon, oxygen, and hydrogen (COOHCOOH).

    • Sulfhydryl Group: Contains sulfur and hydrogen (SHSH).

    • Carbonyl Group: Has a carbon double-bonded to oxygen (C=OC=O).

    • Phosphate Group: Central phosphorus atom linked to oxygen atoms (PO4PO_4).

    • Amino Group: Contains nitrogen and two hydrogen atoms (NH2NH_2).

  • Chemical Processes:

    • Dehydration Synthesis:

    • Joins small molecules into a larger one by removing water.

    • For example: extGlucose+extFructose<br>ightarrowextSucrose+H2Oext{Glucose} + ext{Fructose} <br>ightarrow ext{Sucrose} + H_2O

    • Hydrolysis:

    • Breaks down large molecules into smaller ones by adding water.

    • For example: extSucrose+H2O<br>ightarrowextGlucose+extFructoseext{Sucrose} + H_2O <br>ightarrow ext{Glucose} + ext{Fructose}

  • Carbohydrates:

    • Main energy source for living things.

    • Types include:

    • Monosaccharides: Simple sugars with 3-7 carbon atoms (e.g., glucose).

    • Disaccharides: Two monosaccharides joined (e.g., sucrose).

    • Polysaccharides: Long chains of glucose (e.g., starch, glycogen).

  • Lipids:

    • Types of fats, not soluble in water.

    • Used for energy storage and cellular structure.

    • Types include:

    • Triglycerides: Glycerol + 3 fatty acids.

    • Phospholipids: Key component of cell membranes.

    • Steroids: Include hormones like cholesterol, estrogen, testosterone.

  • Proteins:

    • Made up of amino acids.

    • Function as enzymes, hormones, and in structure (hair, nails).

    • Different levels of structure: primary, secondary, tertiary, quaternary.

  • Nucleotides and Nucleic Acids:

    • Nucleotides are made of a phosphate group, sugar, and base.

    • DNA: Genetic material, has a double helix structure.

    • RNA: Helps make proteins, single-stranded.