Overview
This lecture provides a foundational overview of basic chemistry concepts essential for understanding anatomy and physiology, focusing on atoms, chemical bonds, water properties, and biological macromolecules.
Why Chemistry Matters in A&P
- Understanding biology, especially cell biology, requires a basic knowledge of chemistry.
- Many diseases and bodily functions occur due to chemical reactions at the atomic level.
- Chemistry informs how drugs and treatments interact with the body.
Atoms and Chemical Bonds
- Atoms are the basic units of matter, consisting of protons (+), neutrons (0), and electrons (–).
- Electrons orbit the nucleus and play a key role in chemical reactions and energy transfer.
- Atoms with equal numbers of protons and electrons are neutral.
- Common body atoms: Carbon (C), Hydrogen (H), Oxygen (O), Nitrogen (N), Phosphorus (P), Sulfur (S) — remembered as "CHONPS".
- Molecules form when two or more atoms bond together.
Types of Chemical Bonds
- Covalent bonds: Atoms share electrons (common in biological molecules).
- Ionic bonds: Electrons are transferred from one atom to another, resulting in charged ions (e.g., Na+ and Cl– in salt).
- Electrolytes: Charged ions (Na+, K+, Ca2+, Cl–) dissolved in body fluids, crucial for cell function.
Water and Its Properties
- Water is a polar molecule—oxygen pulls electrons closer, making oxygen slightly negative, hydrogens slightly positive.
- Hydrogen bonds: Weak attractions between water molecules, giving water unique properties like cohesion, adhesion, and high heat capacity.
- Water dissolves polar molecules (like salts and sugars) but not non-polar molecules (like fats and gases).
Polar vs. Non-Polar Molecules & Cell Transport
- "Like dissolves like": Polar dissolves polar; non-polar dissolves non-polar.
- Cell membranes are made of lipids (non-polar), allowing non-polar molecules (e.g., O₂, CO₂) to pass through easily.
- Polar molecules (e.g., glucose) need special proteins to pass through cell membranes.
Macromolecules Overview
Carbohydrates
- Made of C, H, O; basic unit is a monosaccharide (e.g., glucose).
- Prefixes/suffixes: gly-, glu-, -ose, -saccharide.
- Functions: Energy storage (glycogen), immediate energy (glucose), and cell recognition (glycoproteins).
- Monomer: Glucose; Polymer: Glycogen.
Proteins
- Made of C, H, O, N (sometimes S); monomer: amino acid (20 types).
- Prefixes/suffixes: pro-, pept-, -in, -ase, amino-.
- Functions: Enzymes, structure, signaling, and cell building.
- Polymer: Polypeptide/protein.
Lipids
- Made mostly of C, H (less O); includes fats, oils, steroids.
- Prefixes/suffixes: lip-, lipo-, -oid, fatty acid, -one.
- No true monomer/polymer structure; often referred to as triglycerides or fatty acids.
- Functions: Energy storage, cell membranes, hormones.
Nucleic Acids
- Made of C, H, O, N, P; monomer: nucleotide (base, sugar, phosphate).
- Suffix: -nucleic acid (DNA, RNA).
- Functions: Store genetic information (DNA/RNA); provide energy (ATP).
Key Terms & Definitions
- Atom — Basic unit of matter, composed of protons, neutrons, and electrons.
- Covalent Bond — A chemical bond where atoms share electrons.
- Ionic Bond — A bond formed by the transfer of electrons between atoms.
- Electrolyte — A charged particle (ion) in solution, essential for physiological processes.
- Polar Molecule — Molecule with uneven distribution of charge, dissolves well in water.
- Non-Polar Molecule — Molecule with even charge distribution, does not dissolve well in water.
- Hydrogen Bond — Weak attraction between polar molecules.
- Macromolecule — Large molecule made of smaller subunits, essential for life.
Action Items / Next Steps
- Review class PowerPoints for specific carbohydrate and protein examples.
- Draw and label a summary chart of macromolecules: atoms present, monomer, polymer, and function.
- Prepare for next topics: pH and enzymes.