Bio Chap 4

• Carbon's Significance: The sources highlight the critical role of carbon in forming the diverse molecules essential for life.
  
  

• Tetravalence: Carbon's ability to form four bonds makes it uniquely suited to construct a vast array of organic molecules.
  
  

  • Carbon can bond with other carbon atoms, creating chains and rings.

  • It also readily bonds with hydrogen, oxygen, and nitrogen, forming the foundation for biomolecules.

• Carbon Skeletons: The sources explain that carbon skeletons, the backbones of organic molecules, display significant diversity in:
  
  

  • Length: Carbon chains can vary in length.

  • Branching: Chains can be straight or branched.

  • Double Bond Position: The location of double bonds within a carbon chain can differ.

  • Presence of Rings: Carbon atoms can also form rings.

• Miller's Experiments and the Origin of Life: The sources discuss Stanley Miller's experiments, which provide crucial insights into the possibility of abiotic synthesis of organic compounds on early Earth.
  
  

  • 1953 Experiment: Miller's initial experiment simulated conditions thought to exist on early Earth, including a "primeval sea," a reducing atmosphere, and "lightning."
    
    

    • The experiment successfully produced organic molecules, including amino acids and hydrocarbons, supporting the hypothesis that life's building blocks could have originated from non-living matter.

  • 1958 Experiment: In a later experiment, Miller incorporated hydrogen sulfide (H2S), simulating conditions near volcanoes.
    
    

    • Analysis of samples from this experiment in 2011 confirmed the presence of amino acids, suggesting abiotic synthesis under varying early Earth conditions.

• Valence: The sources define valence as the number of covalent bonds an atom can form, a fundamental concept in understanding organic molecule structures.
  
  

  • Figure 4.4 illustrates the valences of carbon (4), hydrogen (1), oxygen (2), and nitrogen (3).

  • Understanding these valences helps explain how these elements combine to create the diversity of organic molecules.

• Hydrocarbons: The sources introduce hydrocarbons as organic molecules consisting solely of carbon and hydrogen.
  
  

  • Examples: Methane (CH4), ethane (C2H6), and ethene (C2H4) are simple hydrocarbons.
    
    

  • Presence in Biomolecules: Hydrocarbons are major components of petroleum and are found in the hydrocarbon tails of fats.
    
    

    • These tails contribute to the hydrophobic nature of fats, explaining their insolubility in water.

    • Hydrocarbons serve as energy sources due to their ability to release energy during reactions.

• Isomers: The sources define isomers as molecules with the same chemical formula but different structures, leading to variations in properties.
  
  

  • Types of Isomers: The sources detail three types of isomers:

    • Structural Isomers: Differ in the covalent arrangement of their atoms, as exemplified by butane and isobutane.
      
      

    • Cis-Trans Isomers (Geometric Isomers): Arise from the restricted rotation around double bonds, leading to different spatial arrangements of atoms.
      
      

    • Enantiomers: Are mirror images of each other due to the presence of an asymmetric carbon.
      
      

      • This subtle difference in spatial arrangement can significantly affect biological activity.

      • Examples include ibuprofen and albuterol, where the two enantiomers exhibit different effectiveness.

• Functional Groups: The sources emphasize the importance of functional groups in shaping the chemical and biological properties of organic molecules.
  
  

  • Role: Functional groups can participate in chemical reactions or indirectly influence molecular function by affecting the molecule's shape.
    
    

  • Major Functional Groups: The sources provide a comprehensive overview of seven key functional groups: hydroxyl, carbonyl, carboxyl, amino, sulfhydryl, phosphate, and methyl groups.
    
    

    • These groups can be hydrophilic, increasing the solubility of organic compounds in water.

    • The methyl group often acts as a tag on biological molecules.

• ATP: The Energy Currency of Cells: The sources highlight adenosine triphosphate (ATP) as the primary energy carrier in cells.
  
  

  • Structure: ATP consists of an adenosine molecule linked to three phosphate groups.
    
    

    • The hydrolysis of one phosphate group from ATP releases energy, fueling various cellular processes.

• Molecular Formulas and Mass: The sources provide examples of writing molecular formulas from structural representations and calculating molecular mass:
  
  

  • Examples of molecular formulas include methane (CH4), ethane (C2H6), ethene (C2H4), myristic acid (C14H28O2), and others.

  • Molecular masses, such as those for myristic acid (228.38 g/mol) and octane (114.23 g/mol), are provided.

These bullet points present a detailed breakdown of the key concepts from the sources, enhancing your understanding of the material.