TChem_Chapter_13__The_Introduction_to_Life

ThanatoChemistry

Chapter 13: The Introduction to Life

• Key chemical elements:

  • Hydrogen (H)

  • Oxygen (O)

  • Nitrogen (N)

  • Carbon (C)

Chapter 13 To-Do's:

• Describe the "Primordial Soup" Theory

• Identify compounds in the atmosphere

• List the building blocks of existence

• Explain the importance of each building block

• Compare and contrast essential vs. non-essential amino acids

• Discuss the significance of amino acids in the body

• Explain the role of nucleotides in the body

• Describe the two classes of nucleotides

• Compare and contrast mono-, di-, oligo-, and polysaccharides

• Discuss the importance of each sugar type in the body

• Describe the characteristics of lipids and naturally occurring lipids in humans

• Define metabolism and compare catabolic vs. anabolic reactions

• Define glycolysis

• Provide a brief overview of the glycolysis → Krebs Cycle → Electron Transport Chain (ETC)

Life - The Primordial Soup

• Primordial Soup Theory:

  • Proposed by Soviet Biologist Alexander Oparin in 1924.

  • Suggests that life began in a "soup" of simple organic compounds.

  • No oxygen present; a chemically reducing atmosphere.

  • Energy sources (like lightning) triggered chemical reactions leading to:

    • Production of monomers (simple compounds)

    • Accumulation of monomers in the "soup"

    • Formation of polymers

    • Evolution to more complex structures, leading to life.

Conditions for Life Development

• Ancient atmosphere:

  • Characterized by:

    • Lack of oxygen

    • Presence of water (H2O), hydrogen (H2), methane (CH4), and ammonia (NH3)

  • Energy (from lightning) leads to the creation of amino acids and other essential molecules.

Building Blocks of Existence

• Elements of Life:

  • 99% of matter consists of:

    • Hydrogen, Oxygen, Nitrogen, and Carbon

  • These elements create macromolecules critical for life (e.g., water, amino acids, nucleobases, carbohydrates, lipids).

Water

• Composes about 60% of an adult’s body mass.

• Properties:

  • Amphoteric and polar molecule; capable of forming hydrogen bonds.

  • Acts as an excellent solvent for nutrient transport in the body.

• Functions:

  • High specific heat allows for temperature regulation in the body.

  • Acts as a lubricant for joints, aids in digestion, and waste excretion (e.g., sweat).

Amino Acids (AAs)

• Building blocks of proteins; 20 unique AAs sustain life.

• Types:

  • 12 non-essential AAs biosynthesized by the body.

  • 8 essential AAs must be obtained through diet.

• Formation Process:

  • Dietary proteins are digested into smaller chains and AAs via enzymes.

  • Absorption occurs through the digestive system into the bloodstream for protein synthesis.

Functional Groups of Amino Acids

• Key functional groups:

  • Carboxylic acid (-COOH)

  • Amine (NH2)

• Classification:

  • Based on side chain properties (e.g., polar, non-polar).

• Common components include hydrogen, carbon, oxygen, nitrogen, and sometimes sulfur.

• Construction of Proteins:

  • AAs link to form polypeptide chains, which fold into functional proteins.

Nucleobases

• Heterocyclic amines categorized into two classes:

  • Purines: Adenine & Guanine

  • Pyrimidines: Cytosine & Thymine (uracil replaces thymine in RNA).

• Nucleobases are key building blocks of nucleic acids (DNA & RNA).

Nucleic Acids

• Macromolecules essential for life:

  • DNA: Double-stranded

  • RNA: Single-stranded

• Function in carrying genetic instructions for organisms.

Carbohydrates

• Categories of Saccharides:

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

  2. Disaccharides: Two monosaccharides linked (e.g., maltose, lactose).

  3. Oligosaccharides: 3-10 saccharide units assisting in cell functioning (recognition & binding).

  4. Polysaccharides: 11+ units; store energy and provide structural components (e.g., glycogen).

Lipid Characteristics

• Hydrophobic and aliphatic; store energy and are components of cell membranes.

• Included in human lipids:

  • Triglycerides, sterols, fat-soluble vitamins, phospholipids.

Enzymes & Metabolism

• Enzymes facilitate metabolic processes, making reactions faster.

• Metabolism Types:

  1. Catabolism: Breaking down large molecules to release energy.

  2. Anabolism: Building larger molecules from smaller ones.

Energy Production

• Energy derived from food involves:

  • Breakdown of large polymers into monomers (proteins → amino acids).

  • Monomers oxidized to produce ATP and energy.

Energy Creation Process

• Glycolysis:

  • Occurs in the cytoplasm; glucose is converted to pyruvate, producing ATP and NADH.

• Krebs Cycle:

  • Takes place in the mitochondria.

  • Acetyl CoA enters to produce ATP, CO2, and NADH.

• Electron Transport Chain:

  • Uses NADH and oxygen to produce additional ATP, heat, and water.

ATP & NADH

• ATP (Adenosine Triphosphate):

  • Transfers chemical energy for metabolic processes.

• NADH (Nicotinamide Adenine Dinucleotide):

  • Coenzyme involved in redox reactions, carrying electrons to various reactions.