Lecture on Organic Chemistry and Physiology

Key Elements in the Human Body

• The four most common elements:
  • Carbon (C)
  • Hydrogen (H)
  • Oxygen (O)
  • Nitrogen (N)
• These elements form the basis of organic molecules essential for physiology.
• Lesser elements and trace elements also exist but are less significant.

Chemical Bonds

• Types of Bonds:
  • Covalent Bonds: Two types - Polar and Non-polar
    • Polar Covalent Bonds: Unequal sharing of electrons, leading to a charge difference across the molecule.
    • Non-polar Covalent Bonds: Equal sharing of electrons.
  • Ionic Bonds: Involves electron transfer, forming charged ions (cation +, anion -).
  • Hydrogen Bonds: Not true bonds but temporary electrostatic attractions.

Ionic and Covalent Bonds

• Ionic Bonds:
  • Involve gain or loss of electrons to become neutral or stable.
  • Examples include electrolytes like calcium, sodium, magnesium, potassium.
  • Electrolytes are ions measured in blood tests.
• Covalent Bonds:
  • Atoms share electrons.
  • Electrons orbit around nuclei of the bonded atoms.
  • Polar Covalent Bonds create molecules like water, facilitating solubility in other polar substances.

Solutions and Solubility

• Solution: A mixture of solute and solvent.
  • Typically water-based in biological systems.
  • Solute: Substance dissolved in solvent (e.g., sodium chloride in water).
• pH Scale:
  • Ranges from 0 to 14; lower numbers are more acidic.
  • Measures hydrogen ion concentration (more H+ ions means more acidic).
  • Pure water has a neutral pH of 7.

Organic vs Inorganic Molecules

• Organic Molecules:
  • Contain carbon-hydrogen bonds.
  • Covalently bonded, large, and non-electrolytic.
  • Major components of living things.
• Inorganic Molecules:
  • Few carbon-hydrogen bonds.
  • Typically ionically bonded, small, and electrolytic.

Functional Groups in Organic Chemistry

• Hydroxyl (OH), Methyl (CH3), Carboxyl, Amino (NH2), Phosphate.
• Important for understanding molecule characteristics and reactions.

Reactions in Organic Chemistry

• Dehydration Synthesis:
  • Removal of water to create new molecules.
  • Example: Formation of maltose from glucose.
• Hydrolysis:
  • Addition of water to break molecules apart.
  • Important in metabolic reactions.

Upcoming Topics

• Enzymes and their roles in facilitating chemical reactions.
• Homework: Complete packet pages 9-12, excluding enzymes section.
• Groups to discuss and understand class materials collaboratively.