Biology Lecture (wk 3) Organic Molecules

Overview of Organic Molecules

• Organic molecules are the building blocks of life, fundamental components of all living organisms.

• They serve as the 'bricks' in the building analogy for life.

• They are primarily based on carbon, impacting the diversity of life on Earth.

Simplest Organic Molecule

• Methane as an example of a simple organic molecule.

• Methane consists of:

  • One carbon atom as the central atom.

  • Four hydrogen atoms bonded via covalent bonds.

• This simple structure can bond with other organic molecules to form more complex structures.

Monomers and Polymers

• Monomers: Small molecules that can bond with others; serve as the basic units (bricks).

• Polymers: Formed by the bonding of multiple monomers into long chains; more complex molecules.

• Dehydration Synthesis:

  • A key process in forming polymers.

  • Involves the removal of a hydroxyl group from one monomer and a hydrogen from another.

  • This releases water and forms a covalent bond between the monomers.

  • Catalyzed by enzymes, which are proteins that enhance the reaction.

Hydrolysis

• Reverse process of polymer formation.

• Enzymes break the covalent bonds in polymers, introducing water to separate the molecules into monomers.

• Hydrolysis:

  • Reintroduces hydroxyl and hydrogen groups to monomers.

• Important in digestion to break down complex organic molecules into simpler forms.

Major Organic Molecules

• Key organic molecules to study:

  • Carbohydrates:

    • Made of monosaccharides (e.g., glucose, galactose).

    • Polysaccharides are formed from monosaccharides (e.g., sucrose, lactose).

  • Lipids:

    • Comprised of triglycerides, phospholipids, and steroids.

    • Serve as energy storage and structural components of membranes.

  • Proteins:

    • Built from amino acids.

    • Amino acids consist of:

      • Amino group (NH2).

      • A carboxyl group (COOH).

      • A side chain (R group) that determines the function.

  • Nucleic Acids:

    • Made of nucleotides.

    • Nucleotides consist of:

      • A phosphate group.

      • A pentose sugar (ribose or deoxyribose).

      • A nitrogenous base.

Functions of Major Organic Molecules

• Carbohydrates:

  • Primary energy source for the body; required for brain function.

  • Broken down into glucose for immediate energy.

• Lipids:

  • Serve as a good energy source and essential for cell membranes.

  • Important for insulation and protection.

• Proteins:

  • The most abundant organic molecules, performing structural, functional, and regulatory roles.

• Nucleic Acids:

  • Responsible for storing and transmitting genetic information.

Conclusion

• Understanding these organic molecules and their functions is essential to studying biology and health sciences. Each molecule plays a vital role in maintaining life and biological processes.