Transcript Macromolecules

Chemistry of Life
Macromolecules
Macromolecules
• Smaller molecules linked together to create
large molecules
– Polymerization
– Have specific 3d shape
• Proteins - enzymes, hormones, structure,
transport
• Carbohydrates – storage, structure
Macromolecules
• Carbon’s properties enable it to make many different
molecules
Isomers =
molecules with the
same formula but
different structural
formulae
Specific 3d shape
Ethane
Functional group
Ethanol
Functional
groups Create the
necessary variety
of shapes of
macromolecules
for life to exist
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
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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 Important to Life
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Carbohydrates
Lipids
Proteins
Nucleic acids
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
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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
• Insoluble 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
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Saturated
No double bonds
Solids @ (200)
Animal fats
Bacon grease, lard,
butter
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Unsaturated
Double bond(s)
Liquids @ (200)
Plant fats (oil)
Corn, peanut, olive
oils
Triglycerides
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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 (?)
Cholesterol
Proteins
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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
Tremendous Variety
Proteins
• Peptide bonds are produced by
DEHYDRATION SYNTHESIS
• String of polypeptide bonds - POLYPEPTIDE
Proteins
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Function depends upon shape
Globular
Fibrous = ‘stringy’
CONFORMATION = 3d shape caused by Hbonds
– 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)
Denaturation
• Some proteins change shape in order to
function
– Receptor, contractile
Nucleic Acids
• DNA, RNA
• Polymers of nucleotides
• Nucleotide:
– Simple sugar (ribose or deoxyribose)
– Nitrogenous base
– Phosphate group (PO4)
4 nitrogenous
bases;
Nucleic Acids
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Nitrogenous bases are complimentary
A-T
C-G
Hydrogen bonds
Sugar-phosphate backbone
H bonding
Relationship
between
nucleic acids
and proteins