Please enable JavaScript.
Coggle requires JavaScript to display documents.
Chapter 5 - The Structure and Function of Large Biological Molecules -…
Chapter 5 - The Structure and Function of Large Biological Molecules
Macromolecules
Classes of Macromolecules
Carbohydrates
Lipids
Proteins
Nucleic Acids
Polymers vs. Monomers
Polymers = long chains of repeating monomers
Built by dehydration reactions (removes water)
Broken down by hydrolysis (adds water)
Carbohydrates
Monosaccharides (simples sugars)
Typically CH2O formula
Glucose, fructose, galactose
Classified by carbonyl group position (aldose/ketose) and number of carbons
Disaccharides
Two monosaccharides joined by glycosidic linkage
Examples: Sucrose (Glucose + Fructose), Lactose (Glucose + Galactose)
Polysaccharides
Lonng chains of monosaccharides
Storage polysaccharides
Starch (plants)
Glycogen (Animals)
Stuctural polysaccharides
Cellulose (plant walls) - humans cannot digest
Chitin (exoskeletons)
Lipids
Not True Polymers
Hydrophobic Molecules (Mostly hydrocarbons)
Fats (Triaclyglycerols)
Glycerol + 3 fatty acids
saturated = no double bonds, straight chains
unnsaturated = one or more double bonds, bent chains
Phospholipids
Glycerol + 2 fatty acids + phosphate head
Amphipathic --> hydrophilic head & hydrophobic tails
Form bilayers (basis of cell membranes)
Steroids
Carbon skleleton with 4 fused rings
Examples: cholesterol, hormones (estrodiol, testosterone)
Proteins
Amino Acids
Amino group (-NH2), carboxyl group (-COOH), side chain (R group)
20 different R groups with different properties
Peptide Bonds
Link amino acids into polypeptides via dehydration synthesis
Protein Structure Levels
Primary: amino acid sequence
Secondary: α-helices & β-pleated sheets (hydrogen bonding in backbone)
Tertiary: 3D folding due to R-group interactions (H-bonds, ionic bonds, hydrophobic interactions, disulfide bridges)
Quaternary: multiple polypeptides assembling into functional protein
Protein Functions
Enzymes, defense (antibodies), storage, transport, hormones, receptors, movement, structure
Denaturation
Unraveling due to heat, pH, salt
Protein loses shape and function
Nucleic Acids
Types
DNA (deoxyribonucleic acid): carries genetic instructions
RNA (ribonucleic acid): involved in protein synthesis
Nucleotides
5-carbon sugar (ribose or deoxyribose)
Phosphate group
Nitrogenous base (A, T/U, C, G)
DNA Structure
Double helix with antiparallel strands
Base pairing (A–T, C–G)
Sugar-phosphate backbone
RNA Structure
Single-stranded
Uracil replaces thymine
Messenger RNA, transfer RNA, ribosomal RNA
Gene Expression
DNA → RNA → Protein
Transcription --> Translation