Medical Biology: Biomolecules Overview

Biomolecules Overview

• Biomolecules are categorized into four main groups: carbohydrates, nucleic acids, proteins, and lipids.
• Each group has distinct structures and functions critical for biological processes.

Carbon: The Framework of Biological Molecules

• Carbon (C) is a tetravalent element essential for life, capable of forming four covalent bonds.
• Carbon molecules can form various structures: straight chains, branches, rings, balls, tubes, and coils.
• Significant elements bonded with carbon include oxygen, nitrogen, sulfur, phosphorus, and hydrogen.

Hydrocarbons

• Hydrocarbons are organic molecules consisting solely of carbon and hydrogen.
• They serve as the main components of fuels such as gasoline and diesel, as well as natural substances in plants and fossil fuels.
• Types of hydrocarbons include:
  • Alkanes: only single bonds between carbon atoms.
  • Alkenes: contain at least one carbon-carbon double bond.
  • Alkynes: contain at least one carbon-carbon triple bond.
  • Aromatic Compounds: contain conjugated double bonds forming stable ring structures.

Functional Groups

• Functional groups are specific atoms or groups of atoms that impart chemical properties to organic compounds.
• Common functional groups include:
  • Hydroxyl (OH)
  • Carboxyl (COOH)
  • Phosphate (PO4)
  • Amino (NH2)
• These groups influence the polarity and reactivity of the molecules they are attached to.

Isomers

• Isomers have the same molecular formula but different structures, leading to varied properties.
• Structural isomers differ in the arrangement of their carbon skeletons.
• Stereoisomers have the same skeletal structure but differ in spatial arrangements.

Enantiomers

• Enantiomers are chiral molecules that are mirror images of each other, influencing polarized light direction.
• The two types of enantiomers are denoted as D (dextrorotatory) and L (levorotatory).

Macromolecules

• Macromolecules are large biomolecules essential for various biological functions and processes.
• The primary types of biological macromolecules are:
  • Carbohydrates: energy storage and structural support.
  • Nucleic Acids: storage and transfer of genetic information (DNA/RNA).
  • Proteins: diverse functions including catalysis, structure, and signaling.
  • Lipids: hydrophobic molecules playing roles in membrane structure and energy storage.