Key Concepts in Chemistry and Biochemistry

Chemistry Learning Objectives

  • Basic structures: atoms, isotopes, ions, and molecules.

  • Compute atomic number, mass number, subatomic particles.

  • Differentiate bonds: covalent (polar/nonpolar), ionic, hydrogen.

  • Importance of water for life.

  • Role of pH and buffers in organisms.

Biochemistry Learning Objectives

  • Identify functional groups and associated macromolecules.

  • Recognize building blocks of carbohydrates, lipids, proteins, nucleic acids.

  • Major physiological reaction categories (hydrolysis, dehydration synthesis, etc.).

Basic Understanding of Matter

  • Matter has mass and occupies space.

  • Elements = basic matter building blocks (not chemically decomposable).

  • Atoms = smallest units of elements retaining properties.

  • Molecules = atoms bonded together.

Common Elements in Human Body

  • Carbon, Hydrogen, Oxygen, Nitrogen.

  • Others: Iron, Calcium, Magnesium, Silicon, Manganese, Argon, Zinc, Selenium, Potassium.

Subatomic Particles

  • Neutrons (neutral), Protons (positive), Electrons (negative).

  • Neutral charge: equal number of protons and electrons.

  • Valence electrons determine chemical bonding.

Isotopes

  • Same atomic number, different mass due to neutron variance.

  • Radioisotopes: unstable, release radiation; practical for dating objects, imaging, and cancer treatment.

Molecular Bonds

  • Ionic Bonds: Electrons are transferred, forming charged ions (e.g., sodium chloride).

  • Covalent Bonds: Electrons are shared (e.g., water, oxygen gas).

  • Hydrogen Bonds: Attractions between covalently bonded hydrogen and negatively charged atoms (water's cohesion).

Properties of Water

  • Liquid at room temperature; high heat of evaporation; less dense as ice; polar solvent.

  • pH Scale: 0 (acidic) to 14 (basic); neutral at pH 7.

Organic Molecules

  • Contains carbon (C) and hydrogen (H), encompasses carbohydrates, lipids, proteins, nucleic acids.

  • Carbohydrates: Short-term energy sources, composed of monosaccharides.

  • Lipids: Hydrophobic molecules for long-term energy, cell membranes, and insulation.

  • Proteins: Comprised of amino acids, diverse functions, can be denatured.

  • Nucleic Acids: Store genetic information, include DNA and RNA (nucleotides).

Protein Structure

  • Primary: Amino acid sequence.

  • Secondary: Folded structures (alpha helices, beta sheets).

  • Tertiary: 3D shape of polypeptides.

  • Quaternary: Assembly of multiple polypeptides.

Energy Molecules

  • ATP (Adenosine Triphosphate): Energy currency of the cell, hydrolyzed to release energy.