Chemical Level of Organisation Summary

Chemical Level of Organisation

• Atoms and Elements:

  • Atoms: Basic particles of matter, composed of protons, neutrons, and electrons.
  • Elements: Pure substances with unique atomic structures, cannot be broken down.

• Isotopes:

  • Variants of elements with the same proton number but different neutrons.

• Energy Levels:

  • Electrons occupy energy levels; the outer layer (valence shell) determines stability and reactivity.
  • Unfilled valence shells lead to unstable atoms that will bond.

• Chemical Bonds:

  • Types: Ionic, covalent (polar/nonpolar), hydrogen.
  • Bonds are formed when atoms gain, lose, or share electrons.

• Molecules and Compounds:

  • Molecule: Atoms bonded covalently.
  • Compound: Atoms from different elements.
  • Mixtures: Combinations of solutes in solvents.

• Types of Energy:

  • Kinetic, chemical, electrical, mechanical, radiant.

• Chemical Reactions:

  • Involve breaking and forming of bonds.
  • Types: Decomposition, synthesis, exchange reactions.

• Role of Enzymes:

  • Lower activation energy, facilitating frequent reactions.

• Inorganic vs Organic Compounds:

  • Inorganic: Generally lack carbon-hydrogen structure.
  • Organic: Contain carbon-hydrogen with various functions.

• Water Properties:

  • Solvent, high heat capacity, lubrication, cushioning.

• pH Importance:

  • Measures hydrogen ion concentration. Normal blood pH: 7.35-7.45.
  • Buffers stabilize pH in body solutions, critical for cell function.

• Acids and Bases:

  • Acids: Release H⁺ and decrease pH.
  • Bases: Accepts H⁺ and increase pH.

• Biomolecules:

  • Carbohydrates: Source of energy, structured (1:2:1 ratio).
  • Lipids: Insoluble in water, store energy, structural functions.
  • Proteins: Chains of amino acids with diverse functions.
  • Nucleic acids: DNA (genetic information) and RNA (protein synthesis).

• High-Energy Compounds:

  • ATP provides energy for enzymatic reactions, transport work, and mechanical action.