Macromolecules
• Smaller molecules linked together to create large molecules
– Polymerization
– Have specific 3d shape • Proteins - enzymes, hormones, structure,
transport
• Carbohydrates – storage, structure
Dehydration synthesis =
enzymatically controlled
formation of macromolecules by removal of
water
Macromolecules
• Macromolecules are broken down (catalyzed) by HYDROLYSIS (‘water splitting’)
• Requires specific enzyme(s)
Check Point
• What are macromolecules?
• Why is carbon so important to life?
• What are functional groups?
• How are macromolecules formed?
• How are macromolecules broken down?
• What molecule makes up most organisms?
Macromolecules
• What do you need to know for each macromolecule:
– Monomers
– Function in organisms
Carbohydrates:
• Carbon + water (hydrate)• Monomers = monosaccharide• Monosaccharides – sugars
– Glucose– Fructose– Galactose– Ribose– Deoxyribose
Monosaccharides
• Monomers may be functional:
– Glucose is primary source of energy for organisms
• Glucose - C6H12O6
• Many monomers form rings in solutions to become more stable
Carbohydrates
• Monosaccharide + monosaccharide =
• Disaccharide
• Glucose + glucose = maltose
• Glucose + fructose = sucrose
• Glucose + galactose = lactose
Polysaccharides
• Polymers of monosaccharides
• Type of monosaccharide and arrangement creates variability in polysaccharides– Starch (Amylose, amylopectin) = plants
– Glycogen = glucose storage for animals
– Cellulose = plant cell walls
– Chitin = exoskeleton of arthropods, some fungi
Carbohydrates: Function
• Energy; stored energy _____(?)
• Structure – ___________(?)
• Cell-to-cell communication, identification (glycoproteins, glycolipids) ______(?)
Lipids • InsolubleInsoluble in water; (long, nonpolar hydrocarbon
chains) • Three types:
– Fats, oils, waxes– Phospholipids – Steroids
Lipids: Fats
• Macromolecules of glycerol + 3 fatty acids
• Fatty acids = hydrocarbon chain (16-18 carbons)
• Fats = triglycerides (3 fatty acids)
• Structure of the fatty acid chains creates different kinds of fats
Fats• Fatty acids may have more or less carbons
atoms in their chains
• Carbon atoms may be double bonded
– Double bonds reduce the number of hydrogen atoms in the chain
– Causes chain to bend
Fats
• Fatty acid chains with double bonds have less hydrogen
• Chains with the maximum amount of hydrogen (no double bonds) are said to be ‘saturated’
• Chains with less than the maximum are said to be ‘unsaturated’
Types of Fats
• Saturated
• No double bonds
• Solids @ (200)
• Animal fats
• Bacon grease, lard, butter
• Unsaturated • Double bond(s)• Liquids @ (200)• Plant fats (oil)• Corn, peanut, olive
oils
Triglycerides
• Important to diet
• Limit amount of saturated fats
• Hydrocarbon chains are high in energy
• More difficult to breakdown
• Link to triglycerides and arteriosclerosis
Lipids: Phospholipids
• Glycerol + 2 fatty acids • 3rd position on the glycerol is
taken by a phosphate group• Major component of cell
membrane
Lipids: Steroids
• 4 fused carbon rings• Cholesterol
– Cell membranes – Help to moderate the effects of extreme
temperatures • Precursors of sex hormones – estrogen, testosterone• Too much causes atherosclerosis (?)
Proteins
• Many shapes = many functions
• Polymers of AMINO ACIDS
• Linked by PEPTIDE BONDS
• POLYPEPTIDES
• Proteins = folded, shaped polypeptides
Proteins: Amino Acids
• 20 different amino acids• R group determines properties of the amino
acid • May be nonpolar, or polar; acidic or alkaline• Essential amino acids - body cannot produce
on its own, must be part of the diet
Proteins
• Peptide bonds are produced by DEHYDRATION SYNTHESIS
• String of polypeptide bonds - POLYPEPTIDE
Proteins
• Function depends upon shape
• Globular
• Fibrous = ‘stringy’
• CONFORMATION = 3d shape caused by H-bonds
– Fold and twist the amino acids
Protein Structure
• Sequence of amino acids
– Determined by genetic code– ‘Goof’ in sequence can have harmful or
lethal effects
Denaturation • Alteration of conformational shape
• Caused by:
– Heat – body T
– pH -
– Salinity
– Organic solvents (alcohols, acetone, etc.)
– Inorganic chemicals that dissolve bonds (HCl)
Nucleic Acids
• DNA, RNA
• Polymers of nucleotides
• Nucleotide:
– Simple sugar (ribose or deoxyribose)
– Nitrogenous base
– Phosphate group (PO4)
Nucleic Acids
• Nitrogenous bases are complimentary
• A-T
• C-G
• Hydrogen bonds
• Sugar-phosphate backbone