SI notes

Biomolecules Overview

  • Discussion focused on the four major classes of biomolecules, particularly proteins and nucleic acids.

Proteins

  • Monomers and Polymers:

    • Proteins are made up of monomers called amino acids.

    • When linked together, amino acids form polymers known as polypeptides.

  • Protein Structures:

    • Primary Structure: Order of amino acids; covalent bonds hold these together tightly.

    • Secondary Structure: Formed through hydrogen bonds between different parts of the polypeptide chain.

    • Tertiary Structure: Overall three-dimensional shape determined by interactions, including hydrogen bonds, which can be impacted by environmental factors.

    • Quaternary Structure: Arrangement of multiple polypeptide chains; can also be influenced by hydrogen bonding.

  • Denaturing:

    • Process where a protein's shape is altered due to disruption of hydrogen bonds, while covalent bonds remain intact.

    • Factors leading to denaturation include temperature and pH changes, rendering the protein inactive.

Nucleic Acids

  • Composition:

    • Nucleic acids are composed of carbon, hydrogen, oxygen, nitrogen, and phosphorus.

    • Long polymers include DNA (deoxyribonucleic acid) and RNA (ribonucleic acid).

  • Nucleotides:

    • The monomers of nucleic acids, consisting of a sugar (monosaccharide), a phosphate group, and a nitrogenous base (A, T, C, or G).

    • Function of Nitrogenous Bases: The identity of each nucleotide is determined by the nitrogenous base.

  • Structure of DNA and RNA:

    • DNA consists of two polymers hydrogen-bonded together, forming a double helix.

    • RNA typically exists as a single polymer.

    • Some viruses may contain RNA as two hydrogen-bonded strands.

  • Adenosine Triphosphate (ATP):

    • A key molecule for energy storage in cells.

    • Important for cellular processes, including the synthesis of new molecules and energy transformation.

    • ATP is generated through the breakdown of carbohydrates like glucose.

Chemical Reactions in Biomolecule Processing

  • Hydrolysis:

    • A process used by the body to break polymers into monomers by adding water, effectively breaking covalent bonds.

  • Dehydration Reaction:

    • Reverse process where monomers are linked together, releasing water in the process.

ATP and Cellular Work

  • Energy Requirement: Every cellular function requires ATP as the energy source.

    • ATP acts as a universal energy currency, enabling cells to perform work, including the synthesis of macromolecules.