Understanding Biological Hierarchy and Chemistry

Sep 5, 2024

Lecture Notes: Biological Hierarchy and Chemical Structures

Overview

  • Review narrated lectures thoroughly.
  • Focus on examining slides that might be skimmed over quickly.

Biological Hierarchy: Starting with Chemical Structures

  • Main Focus: Structure of the atom and formation of molecules.
  • Emergent Properties: New functionalities emerge as we move up the hierarchy.

Basic Chemistry Principles

  • Matter: Composed of elements; takes up space and has weight.
  • Elements: Smallest form retaining basic properties; e.g., Sodium, Chlorine.
  • Examples of Emergent Properties: Sodium + Chlorine = Sodium Chloride (NaCl).

Compounds and Molecules

  • Compounds: Fixed ratio of two or more elements (e.g., NaCl).
  • Molecules: Held together by covalent bonds (e.g., H2O).

Elements in Living Systems

  • Major Elements: Oxygen, Carbon, Hydrogen, Nitrogen (96% of body mass).
  • Other Essential Elements: Potassium, Sodium, Phosphorus, Sulfur.
  • Trace Elements: Iodine, Iron, etc., vital in small amounts.

Atomic Structure

  • Atoms: Basic unit of matter; composed of protons, neutrons, and electrons.
  • Subatomic Particles:
    • Protons: Positive charge.
    • Neutrons: Neutral charge.
    • Electrons: Negative charge.

Isotopes

  • Variants of elements with different neutron numbers.
  • Useful in tracing processes and dating fossils.

Chemical Bonds

  • Covalent Bonds: Strongest, sharing of electron pairs.
  • Ionic Bonds: Transfer of electrons; results in ions.
  • Hydrogen Bonds: Weaker, important for molecule interactions.

Electron Shells and Potential Energy

  • Electron Shells: Different energy levels; potential energy varies.
  • Valence Shells: Outermost shell, determines reactivity and chemical bonds.

Electronegativity and Polar Bonds

  • Electronegativity: Tendency to attract electrons.
  • Polar Bonds: Unequal sharing of electrons, e.g., in water.

Visualizing Molecules

  • Molecular Formulas: Show number and type of atoms.
  • Lewis Dot/Structural Diagrams: Show arrangement and bonds.

Chemical Reactions

  • Chemical Reactions: Making and breaking chemical bonds.
  • Equilibrium: Forward and reverse reactions occur at the same rate.
  • Balancing Equations: Must start and end with same number of atoms.

Important Concepts in Chemistry

  • Valence Capacity: Number of bonds needed for stability.
  • Energy in Reactions: Potential energy changes with electron arrangement.

Moving Forward

  • Next focus: Importance and properties of water as a life-giving compound.

These notes encompass essential points from the lecture on the biological hierarchy and chemical structures, focusing on the atom, molecules, and the fundamental chemistry underpinning biological systems.