Biological Macromolecules Overview
Key Functions of Biological Macromolecules
- Speed up biochemical reactions (catalysts).
- Transport substances across cell membranes.
Types of Bonds in Proteins
- Peptide bond links amino acids together.
DNA vs RNA
- DNA: Double-stranded, contains Thymine, sugar is deoxyribose.
- RNA: Single-stranded, contains Uracil, sugar is ribose.
Energy Sources
- Quick energy source: Carbohydrates (e.g., glucose).
- Long-term energy storage: Lipids (twice as much energy per gram than carbohydrates).
Macromolecules Classification
- Polymer: Large molecule made from repeating units (monomers).
- General formula for carbohydrates: 1:2:1 ratio of Carbon, Hydrogen, and Oxygen.
Lipids and Their Properties
- Lipids are hydrophobic due to long C-H chains; they do not mix with water.
Building Blocks of Macromolecules
- Building block of carbohydrates: Monosaccharide.
- Building block of nucleic acids: Nucleotide.
Enzymatic Function
- Enzymes lower activation energy to speed up reactions.
Nucleotides and Macromolecules
- Not part of a nucleotide: Fatty acid chain.
Phospholipids Structure
- Amphipathic: Contain hydrophilic heads and hydrophobic tails.
Polysaccharides in Plants
- Storage polysaccharide: Starch (amylose and amylopectin).
- Example: DNA, dictates amino acid sequence of proteins.
Energy Comparison
- Highest energy yield per gram: Lipids > Proteins > Carbohydrates.
- Proteins not primary energy source, used in extreme conditions (e.g., starvation).
Storage of Fuel
- Sugars stored as glycogen (short-term); fats stored compactly (long-term).
Functions of Lipids
- Not mainly for fighting diseases; primarily for membranes and energy storage.