Biology 3
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Transcript of Biology 3
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MacromolecMacromoleculesules
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Organic Organic CompoundsCompounds
• CompoundsCompounds that contain CARBONCARBON are called organicorganic.
• MacromoleculesMacromolecules are large organic moleculesorganic molecules.
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Carbon (C)Carbon (C)• CarbonCarbon has 4 electrons4 electrons in
outer shell.
• CarbonCarbon can form covalent covalent bondsbonds with as many as 4 4 other atoms (elements).
• Usually with C, H, O or NC, H, O or N.
• Example:Example: CHCH44(methane)(methane)
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Biological Macromolecules
• Large organic molecules.Large organic molecules.• Also called POLYMERSPOLYMERS.• Made up of smaller “building
blocks” called MONOMERSMONOMERS.Most biologically important
macromolecules molecules fall into the following groups:
1. Carbohydrates1. Carbohydrates2. Lipids2. Lipids3. Proteins3. Proteins4. Nucleic acids (DNA and 4. Nucleic acids (DNA and
RNA)RNA)
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Dehydration SynthesisDehydration Synthesis
• Also called “condensation “condensation reaction”reaction”
• Forms polymerspolymers by combining monomersmonomers by “removing “removing water”water”.
HO H
HO HO HH
H2O
How Are Macromolecules Formed?How Are Macromolecules Formed?
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HydrolysisHydrolysis•Separates monomersmonomers by
“adding water”“adding water”
HO HO HH
HO H
H2O
How are Macromolecules separated or How are Macromolecules separated or digested?digested?
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CarbohydratesCarbohydrates• Consist of carbon, hydrogen, & oxygen• Energy containing molecules• Some provide structure• Basic building block is a monosaccharide
(CH2O)n ; n = 3,5,6• Two monosaccharides form a disaccharideSmall sugar moleculesSmall sugar molecules to large sugar moleculeslarge sugar molecules.
• Examples:Examples:A.A. monosaccharidemonosaccharideB.B. disaccharidedisaccharideC.C. polysaccharidepolysaccharide
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CarbohydratesCarbohydratesMonosaccharide: one sugar Monosaccharide: one sugar
unitunit
Examples:Examples: glucose (glucose (C6H12O6)
deoxyribosedeoxyribose
riboseribose
FructoseFructose
GalactoseGalactose
glucoseglucose
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CarbohydratesCarbohydrates
Disaccharide: two sugar unitDisaccharide: two sugar unit
Examples: Examples: – Sucrose (glucose+fructose) (Table Sucrose (glucose+fructose) (Table
Sugar)Sugar)– Lactose (glucose+galactose) (Milk Lactose (glucose+galactose) (Milk
Sugar)Sugar)– Maltose (glucose+glucose)Maltose (glucose+glucose)
glucoseglucoseglucoseglucose
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CarbohydratesCarbohydratesPolysaccharide: many sugar Polysaccharide: many sugar
unitsunits
Examples:Examples: starch (bread, starch (bread, potatoes)potatoes)
glycogen (beef glycogen (beef muscle)muscle)
cellulose (lettuce, cellulose (lettuce, corn)corn)
glucoseglucoseglucoseglucose
glucoseglucoseglucoseglucose
glucoseglucoseglucoseglucose
glucoseglucoseglucoseglucose
cellulosecellulose
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CarbohydratesCarbohydratesImportant Polysaccharides
Starch and Glycogen:
• Starch is energy storage molecule in plants• Glycogen is energy storage molecule in animals.• Starch and glycogen can be digested by
animals.
Cellulose:
• Different bond formed than starch• Structural component in plants• Cannot be digested by animals
Chitin• Partly derived from non-sugars (nitrogen)• Composes exoskeletons of insects
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LipidsLipids• Composed of Carbon, Hydrogen, and Oxygen• Building blocks are fatty acids and glycerol.• Energy storage molecules “stores the most “stores the most
energy”energy”• not soluble in waternot soluble in water.• are soluble in hydrophobic solventsare soluble in hydrophobic solvents.
• Examples:Examples: 1. Fats1. Fats2. Phospholipids2. Phospholipids3. Oils3. Oils4. Waxes4. Waxes5. Steroid hormones5. Steroid hormones6. Triglycerides6. Triglycerides
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LipidsLipidsSix functions of lipids:Six functions of lipids:
1.1. Long term Long term energy storageenergy storage
2.2. Protection against heat loss Protection against heat loss (insulation)(insulation)
3.3. Protection against physical shockProtection against physical shock
4.4. Protection against water lossProtection against water loss
5.5. Chemical messengers (hormones)Chemical messengers (hormones)
6.6. Major component of membranes Major component of membranes (phospholipids)(phospholipids)
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LipidsLipidsTriglycerides:Triglycerides:
ccomposed of 1 glycerol1 glycerol and 3 3 fatty acidsfatty acids.
H
H-C----O
H-C----O
H-C----O
H
glycerol
O
C-CH2-CH2-CH2-CH2-CH2-CH2-CH2-CH2-CH2-CH3
=
fatty acids
O
C-CH2-CH2-CH2-CH2-CH2-CH2-CH2-CH2-CH2-CH3
=
O
C-CH2-CH2-CH2-CH =CH-CH2 -CH
2 -CH2 -CH
2 -CH3
=
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Fatty AcidsFatty AcidsThere are two kinds of fatty acidsfatty acids you may see these on
food labels:
1.1. Saturated fatty acids:Saturated fatty acids: no double bonds (bad) no double bonds (bad)
2.2. Unsaturated fatty acids:Unsaturated fatty acids: double bonds (good) double bonds (good)O
C-CH2-CH2-CH2-CH2-CH2-CH2-CH2-CH2-CH2-CH3
=
saturatedsaturated
O
C-CH2-CH2-CH2-CH=CH-CH2 -CH
2 -CH2 -CH
2 -CH3
=
unsaturated