Chapter 5~ The Structure & Function of Macromolecules 5.1-5.5.
Chapter 5 Structure & Function of Macromolecules.
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Transcript of Chapter 5 Structure & Function of Macromolecules.
Chapter 5
Structure & Function of Macromolecules
• Macromolecules
• Monomer
• Dimer
• Polymer
• Dehydration synthesis –
(condensation reaction)
removal of a water molecule when 2 simpler substances join
• Hydrolysis –
breaking down compounds by the
addition of water
Organic compounds1) Carbohydrates –
• contain C, H, O
• Short term energy sources
• Ratio of H:O is 2:1
• Examples: sugars, starches
Carbohydrates
a) Monosaccharides –
• sugar monomers
ex: glucose, fructose, galactose
C6H12O6
b) Disaccharides –
• 2 monosaccharides joined by a
glycosidic linkage
ex: lactose, maltose, sucrose
C12H22O11
Dehydration synthesis
c) Polysaccharides -
• 3 or more sugar monomers joined
ex: amylose, glycogen, cellulose, chitin
2) Lipids
• Contain C, H, O
• Ratio of H:O is not 2:1
• Examples: fats, oils, waxes, steroids
• Long-term energy storage
• Glycerol, fatty acids are monomers
Figure 5.10 The synthesis and structure of a fat, or triacylglycerol
• Phospholipids –
– 2 fatty acids, glycerol, PO4 group
– Important in membrane structure
• Cholesterol –
– Basis of other steroids
Phospholipids
Saturated Unsaturated
3) Proteins
• Contain C, H, O, N, sometimes P, S
• Structure, transport, synthesizing hormones,
defense, coordination
• Amino acids are protein monomers
Amino acid
1. Amino group 3. Carboxyl group2. R group
Protein conformationPrimary structure –
polypeptide chains• Secondary structure –
helix, pleated sheets, both due to
H bonds• Tertiary structure –
due to bonding between side chains
H bonds, ionic bonds, disulfide bridges
• Quaternary structure –
2 or more polypeptide subunits join to make functional protein
Figure 5.18 The primary structure of a protein
Secondary (2°) StructureFolds in part of amino acid chain: Hydrogen
bonds
- pleated sheet -helix
Figure 5.22 Examples of interactions contributing to the tertiary structure of a protein
Interactions between 2+ polypeptides
Quaternary (4°) Structure
Protein conformation
Figure 5.17 Conformation of a protein, the enzyme lysozyme
Shape is critical for protein interactions
EXAMPLE:
Hemoglobin•4 Polypeptides•Binds Iron•Oxygen transport
Figure 5.19 A single amino acid substitution in a protein causes sickle-cell disease
• Denaturation –
-protein unravels and loses native conformation
-may be caused by changes in pH, salinity, temperature, or concentration
pH
Heat
Chemicals
What can cause proteins to denature?
4) Nucleic acids
• Contain C, H, O, N, P
• Polymers
• DNA and RNA
• Monomers are nucleotides joined by covalent bonds called phosphodiester linkages
• Function in storage and transfer of
information
Figure 5.29 The components of nucleic acids