Chemistry of the Body: Foundations for Anatomy & Physiology

Element vs. Compound: Structure, Function, and Role in Anatomy & Physiology

Introduction

Understanding the difference between elements and compounds is fundamental to grasping the chemical basis of life. Elements are pure substances consisting of only one type of atom, while compounds are substances formed from two or more elements chemically bonded together.

• Atomic Structure vs. Compound (Molecules): Elements have a unique atomic structure; compounds are made of molecules containing different atoms.

• Isotopes/Radiosotopes: Isotopes are atoms of the same element with different numbers of neutrons. Radioisotopes are unstable isotopes that emit radiation; they have medical and research applications but also pose risks.

• Bonding: Chemical bonds hold atoms together in compounds. Ionic bonds involve the transfer of electrons, while covalent bonds involve sharing electrons. Hydrogen bonds are weaker interactions important in biological molecules.

• Importance of H bonds: Hydrogen bonds stabilize the structure of proteins and DNA, and contribute to water's unique properties.

Acids, Bases, pH Scale & Buffers

Introduction

Acids and bases are substances that alter the concentration of hydrogen ions in a solution, affecting pH. Buffers help maintain stable pH in biological systems.

• Homeostasis & pH: Maintaining a stable pH is vital for cellular function and overall homeostasis.

• OH-, H+, pH, H2O: The pH scale measures the concentration of hydrogen ions (H+) in a solution. Acidic solutions have more H+, while basic solutions have more hydroxide ions (OH-).

• Acids vs. Bases/Alkalosis: Acids donate H+ ions; bases accept H+ ions. Alkalosis refers to a condition where the body fluids have excess base (high pH).

• Buffers: Buffers are mixtures that resist changes in pH by neutralizing excess acids or bases. They are crucial for metabolic processes.

• Importance: Proper pH control is essential for enzyme activity, metabolic reactions, and overall health.

Properties of H2O & Importance to Living Cells

Introduction

Water is the most abundant molecule in living organisms and is essential for life due to its unique chemical and physical properties.

• Polar Compound: Water is a universal solvent due to its polarity, allowing it to dissolve many substances necessary for cellular function.

• High Heat Capacity: Water can absorb and retain heat, helping to maintain stable body temperature.

• Examples: Water participates in chemical reactions, transports nutrients, and removes waste.

4 Major Organic Compounds – Carbohydrates, Lipids, Proteins, Nucleic Acids

Introduction

Organic compounds are molecules containing carbon and are essential for life. The four major classes are carbohydrates, lipids, proteins, and nucleic acids, each with distinct functions and structures.

• Overall Function(s) & Structure: Each class of organic compound has unique roles in the body and characteristic molecular structures.

• Monomers: The basic building blocks of each compound:

  • Carbohydrates: Monosaccharides (simple sugars)

  • Lipids: Fatty acids and glycerol

  • Proteins: Amino acids

  • Nucleic Acids: Nucleotides

• Specific Examples & Roles:

  • Glucose: An immediate energy source for cellular respiration.

  • Glycogen: A storage form of glucose/energy in the liver and muscles.

  • Lipids: Contain -COOH (carboxyl group); used for long-term energy storage, insulation, and cell membranes.

  • Proteins: Contain -COOH and -NH2 (amino group); serve as enzymes, structural components, and signaling molecules.

• Functional Groups: Specific groups of atoms within molecules that determine their chemical properties and reactions.

  • Carboxyl group (-COOH): Found in amino acids and fatty acids.

  • Amino group (-NH2): Found in amino acids.

• Carbohydrates:

  • Classes: Monosaccharides, disaccharides, polysaccharides.

  • Function: Provide energy and structural support.

Table: Comparison of the Four Major Organic Compounds

Compound Class	Monomer	Main Function	Key Example
Carbohydrates	Monosaccharide	Energy source, structure	Glucose, Glycogen
Lipids	Fatty acid & Glycerol	Energy storage, insulation, membranes	Triglyceride, Phospholipid
Proteins	Amino acid	Enzymes, structure, signaling	Hemoglobin, Enzymes
Nucleic Acids	Nucleotide	Genetic information, protein synthesis	DNA, RNA

Key Equations

• pH Calculation: $pH = -\log_{10}[H^+]$

• General Formula for Carbohydrates: $(CH_2O)_n$

Additional info: The notes have been expanded to include definitions, examples, and a comparison table for clarity and completeness. Functional groups and monomers are described for each organic compound class.