Lecture Notes: Chemistry and the Human Body

Introduction

• Not meant to be a chemistry course
• Purpose: Basic understanding of terminology related to chemistry in digestion, hormone control, etc.
• Focus on becoming comfortable with terms in this chapter

Key Concepts in Chemistry

Matter and Atoms

• Matter: Has weight and takes up space
• Atom: Smallest part of matter; invisible
• Chemistry: Study of matter's composition

Atomic Structure

• Atoms have a central nucleus (positively charged protons, neutral neutrons)
• Negatively charged electrons orbit the nucleus
• Atoms combine to form molecules and compounds

Molecules and Compounds

• Molecule: Chemical combination of two or more atoms
  • Examples: Oxygen (O2), Water (H2O)
• Compound: Molecules with more than one element
  • Example: Sugar (C6H12O6)
• Chemical Formulas: Describe the elements in compounds (e.g., H2O for water)

Chemical Bonds

• Ionic Bonds: Atom receives electrons from another atom to complete outer shell
  • Example: Sodium Chloride (NaCl)
• Electrolytes: Ionic compounds that dissociate in water
  • Examples: Sodium (Na+), Potassium Chloride (KCl), CO2, HCO3 (bicarbonate)
• Covalent Bonds: Atoms share electrons
  • Example: Hydrogen gas (H2)
• Hydrogen Bonds: Weak bonds between neighboring molecules (e.g., water, DNA, proteins)

Types of Chemistry

• Inorganic Chemistry: Non-living matter
• Organic Chemistry: Living matter
• Water: Universal solvent; participates in many chemical reactions

Chemical Reactions

• Dehydration Synthesis and Hydrolysis: Reactions involving water
• Reactions involve energy transfer
• Enzymes: Functional proteins that speed up chemical reactions without being changed

Important Elements and Compounds

• Common elements: Hydrogen (H), Sodium (Na+), Nitrogen (N), Potassium (K+), Iron (Fe), Carbon (C), Oxygen (O), Chloride (Cl), Carbonic Acid (HCO3), Salt (NaCl)

pH and Homeostasis

• pH: Represents the amount of hydrogen in a solution
  • More hydrogen: More acidic
  • pH below 7.0: Acidic, above 7.0: Basic (alkaline)
  • Normal human pH: 7.35 to 7.45
  • Essential for bodily functions to maintain normal pH
• Buffers: Help maintain pH balance

Lipids

• Lipids: Fats and oils
  • Triglycerides: Store energy
  • Phospholipids: Make up cell membranes
  • Cholesterol: Needed for producing steroid hormones and regulating body chemistries

Proteins and Nucleic Acids

• Proteins: Large molecules, basic unit is amino acids (contain nitrogen)
  • Peptide Bond: Holds amino acids together
  • Structural (e.g., collagen) vs. Functional (e.g., enzymes)
• Nucleic Acids: DNA and RNA
  • Made of nucleotides: phosphate unit, ribose sugar, and nitrogen base
  • Determine individual identity and cell behavior

Conclusion

• Importance of familiarizing with terms
• Essential for understanding digestion and genetics

Future Topics: Review of cells' anatomy and physiology