Fundamental Chemistry Concepts for Anatomy & Physiology

Basic Chemical Principles in Anatomy & Physiology

Key Terms and Definitions

• Anabolic/Anabolism: The process of building complex molecules from simpler ones, requiring energy.

• Catabolic/Catabolism: The breakdown of complex molecules into simpler ones, releasing energy.

• Atom: The smallest unit of matter that retains the properties of an element.

• Atomic Number: The number of protons in the nucleus of an atom, which determines the element.

• ATP (Adenosine Triphosphate): The primary energy carrier in cells.

• Covalent Bond: A chemical bond formed by the sharing of electron pairs between atoms.

• Dissociate: The process by which molecules split into smaller particles such as ions.

• DNA (Deoxyribonucleic Acid): The molecule that carries genetic information in cells.

• Electrolyte: A substance that dissociates into ions in solution and is capable of conducting electricity.

• Endergonic: A reaction that absorbs energy.

• Exergonic: A reaction that releases energy.

• Hydrophilic: Molecules that are attracted to water.

• Hydrophobic: Molecules that repel water.

• Ion: An atom or molecule with a net electric charge due to the loss or gain of electrons.

• Mass: The amount of matter in an object.

• Matter: Anything that has mass and occupies space.

• Metabolism: All chemical reactions that occur within an organism.

• Solute: The substance dissolved in a solution.

• Solution: A homogeneous mixture of two or more substances.

• Solvent: The substance in which the solute is dissolved.

Atoms, Elements, and Subatomic Particles

Structure and Properties

• Mass Determination: The mass of an object is determined by the sum of the masses of its atoms and molecules.

• Major Elements in the Human Body: Four elements make up about 96% of the body's mass: Carbon (C), Hydrogen (H), Oxygen (O), and Nitrogen (N).

• Subatomic Particles:

  • Proton: Positive charge (+1), located in the nucleus.

  • Neutron: No charge (0), located in the nucleus.

  • Electron: Negative charge (-1), located in orbitals around the nucleus.

Chemical Bonds and Reactions

Types of Bonds

• Covalent Bond: Atoms share electrons. Can be polar (unequal sharing) or nonpolar (equal sharing).

• Ionic Bond: Formed when one atom donates an electron to another, creating oppositely charged ions that attract.

• Polar Covalent Bond: Electrons are shared unequally, resulting in partial charges.

• Nonpolar Covalent Bond: Electrons are shared equally, no charge separation.

Chemical Reactions

• Synthesis Reaction: Two or more simple substances combine to form a more complex substance. Also called anabolic reaction. General equation: $A + B \rightarrow AB$

• Decomposition Reaction: A complex molecule breaks down into simpler substances. Also called catabolic reaction. General equation: $AB \rightarrow A + B$

Organic vs. Inorganic Compounds

Classification and Examples

• Organic Compounds: Contain carbon and hydrogen, usually large and complex (e.g., carbohydrates, proteins, lipids, nucleic acids).

• Inorganic Compounds: Usually do not contain both carbon and hydrogen (e.g., water, salts, acids, bases).

Acids, Bases, and pH

pH Scale and Indicators

• pH Scale: Measures the concentration of hydrogen ions ($[H^+]$) in a solution. Ranges from 0 (acidic) to 14 (basic), with 7 being neutral.

• Acid: Substance that increases $[H^+]$ in solution; pH less than 7.

• Base: Substance that decreases $[H^+]$ or increases $[OH^-]$; pH greater than 7.

• Neutral: pH of 7; pure water.

• Buffer: Substance that maintains perfect neutrality on the pH scale.

Macromolecules: Lipids, Proteins, Carbohydrates, Nucleic Acids

Lipids

• Composition: Made up of fatty acids and glycerol.

• Most Plentiful Lipid: Triglycerides are the most abundant lipid in the human body and diet.

• Energy Value: Lipids provide about 9 calories per gram.

Proteins

• Composition: Made up of amino acids.

• Examples: Enzymes, antibodies, hemoglobin, actin, myosin.

Carbohydrates

• Classification:

  1. Monosaccharides: Simple sugars (e.g., glucose, fructose).

  2. Disaccharides: Two monosaccharides joined (e.g., sucrose, lactose).

  3. Polysaccharides: Many monosaccharides (e.g., starch, glycogen).

Nucleic Acids

• DNA: Stands for Deoxyribonucleic Acid. Contains genetic instructions.

• Bases in DNA: Adenine (A), Thymine (T), Cytosine (C), Guanine (G). Pairing: A-T, C-G.

• RNA: Main function is protein synthesis. Made in the nucleus by transcription.

Water and Inorganic Substances

Importance and Examples

• Water: Most plentiful inorganic substance in the body. Essential for chemical reactions, temperature regulation, and transport.

• Electrolytes: Important for nerve impulse transmission, muscle contraction, and maintaining fluid balance.

Chemical Symbols and Classification

Common Elements and Compounds

Element/Compound	Chemical Symbol
Carbon	C
Hydrogen	H
Nitrogen	N
Helium	He
Calcium	Ca
Oxygen	O
Water	H2O
Zinc	Zn
Sodium Chloride	NaCl

Unusual Chemical Symbols

• Some chemical symbols are derived from Latin names, not English (e.g., Sodium = Na from 'Natrium', Potassium = K from 'Kalium').

• Examples:

  • Sodium: Na

  • Potassium: K

  • Iron: Fe

Additional Info

• Metabolism includes both anabolic and catabolic reactions, essential for maintaining life.

• Buffers in the body help maintain pH homeostasis, crucial for enzyme function.

• Electrolytes such as sodium, potassium, and calcium are vital for physiological processes.