Co_A&P_1e_PPT_CH03_revise_p2

Chapter 3: The Chemical Level of Organization

Introduction

• This chapter explores the fundamental chemistry concepts relevant to the human body including:

  • Matter

  • Atoms and molecules

  • Chemical bonds

  • Inorganic and organic compounds

Icebreaker Questions

• What molecules are present in the human body?

• Define organic molecules.

• What are the chemical reactions necessary for life?

• Locations of molecules in living organisms?

Section 3.1: Elements and Atoms

Basic Definitions

• Matter: Anything occupying space and having mass (not weight).

• Mass: Amount of matter in an object, consistent regardless of gravity.

Elements and Compounds

• Elements: Pure substances, single type of atom.

• Atoms: Smallest unit retaining properties of an element.

• Molecules: Two or more atoms chemically bonded.

• Compounds: Two or more different elements chemically combined.

Section 3.2: Chemical Bonds

Types of Bonds

1. Ionic Bonds: Formed between charged ions (cations and anions) with opposite charges. Example: Sodium chloride (NaCl).

2. Covalent Bonds: Formed by sharing electrons. Can be:

   • Nonpolar Covalent: Equal sharing of electrons.

   • Polar Covalent: Unequal sharing of electrons, resulting in partial charges.

3. Hydrogen Bonds: Non-covalent attractions between molecules, like those in water, contributing to properties such as high surface tension.

Electron Behavior

• Electron Shells: Regions where electrons reside; filled shells lead to stability.

• Valence Shell: Outermost shell; its stability strongly influences chemical reactivity.

Section 3.3: Chemical Reactions

Role of Energy in Reactions

• **Energy Forms: **

  • Potential energy: Stored energy.

  • Kinetic energy: Energy of motion;

  • Chemical energy: Energy in chemical bonds.

  • Exergonic Reactions: Release energy.

  • Endergonic Reactions: Absorb energy; typically require input to occur.

Types of Reactions

1. Synthesis Reactions: Combine reactants to form products.

2. Decomposition Reactions: Break down compounds into simpler components.

3. Exchange Reactions: Involve both synthesis and decomposition.

Section 3.4: Inorganic Compounds

Inorganic vs. Organic Compounds

• Inorganic Compounds: Lack carbon and hydrogen. Examples include water, salts, acids, and bases.

• Organic Compounds: Contain carbon and hydrogen, comprising key macromolecules (carbohydrates, lipids, proteins, nucleic acids).

Role of Water in the Body

• Comprises 50-70% of body mass.

• Functions include:

  • Joint lubrication.

  • Cushioning cells.

  • Temperature regulation.

  • Solvent for ions and nutrients.

Solutions and Solubility

• Solution: A mixture of solute and solvent (e.g., nutrients dissolved in water).

• Water as a universal solvent supports numerous biochemical processes.

Section 3.5: Organic Compounds

Types of Biological Macromolecules

1. Carbohydrates: Energy source, with monomers being monosaccharides.

   • Types: Monosaccharides, disaccharides, polysaccharides.

2. Lipids: Primarily energy storage molecules, including triglycerides, which provide insulation.

3. Proteins: Composed of amino acids; involved in structure, transport, and catalysis.

4. Nucleic Acids: DNA and RNA responsible for genetic information and protein synthesis.

Enzymes and Catalysis

• Enzymes are biological catalysts facilitating chemical reactions by lowering activation energy.

• Specificity for substrates is determined by the enzyme's active site, allowing for efficient reaction processes.

Summary of Chapter 3

• Understanding of chemistry's language and concepts as they relate to the human body.

• Recognition of matter organization and chemical bonding.

• Awareness of essential inorganic and organic compounds in physiological processes.