BackBiomolecules: Structure, Function, and Biological Importance
Study Guide - Smart Notes
Tailored notes based on your materials, expanded with key definitions, examples, and context.
Organic Molecules & Biomolecules
Definition and Classification
Organic molecules are compounds found in or derived from living organisms, primarily composed of carbon and hydrogen arranged in rings or chains. Biomolecules (macromolecules) are a subset of organic molecules essential for life and are present in all living organisms.
Biomolecules include carbohydrates, proteins, nucleic acids, and lipids.
They serve as the building blocks and functional molecules within cells.
Monomers & Polymers
Structure and Formation
Biomolecules are often polymers, which are large molecules made by joining smaller units called monomers (building blocks or subunits). The process of forming polymers from monomers involves specific chemical reactions.
Monomers: Small molecules that serve as the repeating units of polymers.
Polymers: Large molecules formed by linking monomers together.
Dehydration synthesis: A reaction where a water molecule is removed to form a new covalent bond between monomers, creating polymers.
Hydrolysis: A decomposition reaction where water is added to break the bonds in polymers, releasing monomers.
Example: Formation and breakdown of sucrose (a disaccharide) via dehydration synthesis and hydrolysis.
Polymers and Their Monomers
Polymer | Monomer |
|---|---|
Carbohydrate | Monosaccharide |
Protein | Amino Acid |
Nucleic Acid | Nucleotide |
Lipid | [None] |
Additional info: Lipids are not true polymers as they are not formed by repetitive monomer units.
Review of Dehydration Synthesis
Mechanism and Importance
Dehydration synthesis is a chemical reaction that links monomers together to form polymers by removing a water molecule. This process is catalyzed by enzymes and is essential for building macromolecules in cells.
Enzymes remove an -OH group from one monomer and an -H from another, releasing H2O.
Creates a covalent bond, resulting in a longer polymer.
Equation:
Review of Hydrolysis
Mechanism and Importance
Hydrolysis is a chemical reaction that breaks polymers into monomers by adding water. Enzymes catalyze this reaction, which is crucial for digestion and cellular metabolism.
Water is added to break the covalent bond between monomers.
Results in the release of individual monomers from the polymer.
Equation:
Summary Table: Biomolecule Polymers and Monomers
Biomolecule | Polymer | Monomer |
|---|---|---|
Carbohydrate | Polysaccharide | Monosaccharide |
Protein | Polypeptide | Amino Acid |
Nucleic Acid | DNA/RNA | Nucleotide |
Lipid | Triglyceride, Phospholipid, Steroid | Fatty acids, Glycerol (not true monomers) |
Additional info: Lipids are assembled from smaller molecules but do not form true polymers.
Key Concepts
Dehydration synthesis builds polymers from monomers by removing water.
Hydrolysis breaks polymers into monomers by adding water.
Enzymes catalyze both reactions, ensuring efficient metabolism and macromolecule turnover.
Example: The formation of starch from glucose monomers in plants, and the breakdown of starch into glucose during digestion.
