The Chemistry of Organic Molecules Chapter 3
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Outline Organic vs Inorganic Functional Groups and Isomers Macromolecules – Carbohydrates – Lipids – Proteins – Nucleic Acids
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Organic Molecules
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Carbon Atom
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Organic - Living Inorganic - Nonliving – Organic molecules contain both carbon and hydrogen. Four categories: ! Carbohydrates ! Lipids ! Proteins ! Nucleic Acids
Carbon atoms contain a total of 6 electrons, with only four in the outer shell. – Very diverse as it can bond with up to four different elements. ! Often shares with other carbon atoms, producing long carbon chains. " Hydrocarbons are chains of carbon bonded only to hydrogen atoms.
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Functional Groups and Isomers
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Functional groups are specific combinations of bonded atoms that always react in the same manner, regardless of the particular carbon skeleton. – Determine polarity of organic molecule.
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Isomers
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Macromolecules
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Isomers are organic molecules that have identical molecular formulas but a different arrangement of atoms.
Carbohydrates, lipids, proteins, and nucleic acids are referred to as macromolecules because of their large size. – Polymers are made up of monomers. Dehydration - Removal of water molecule. Hydrolysis - Addition of water molecule. – Enzymes speed up reactions.
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Carbohydrates
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Lipids
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Used as immediate energy sources. – Monosaccharides - Single sugar molecule. ! Glucose, ribose, deoxyribose – Disaccharides - Contain two monosaccharides joined during dehydration reaction. ! Sucrose – Polysaccharides - Polymers of monosaccharides. ! Starch, cellulose, chitin
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Insoluble in water due to hydrocarbon chains. Fats – Glycerol - Contains three OH- groups. ! Triglycerides - Three fatty acids attached to each glycerol molecule. " Fatty acid consists of long hydrocarbon chain. # Saturated - No double bonds. # Unsaturated - Double bonds.
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Fat and Fatty Acids
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Lipids Phospholipids – Instead of third fatty acid attached to glycerol as in fat, there is a polar phosphate group. ! Hydrophilic heads and hydrophobic tails. " Arrange themselves so polar heads are adjacent to water. # Bulk of cell plasma membrane consists of phospholipid bilayer.
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Phospholipids
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Lipids Steroid – Have skeletons of four fused carbon rings. ! Cholesterol, testosterone, estrogen Waxes – Long-chain fatty acid bonds with a longchain alcohol. ! High melting point ! Waterproof ! Resistant to degradation
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Proteins
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Proteins
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Functions – Support – Enzymes – Transport – Defense – Hormones – Motion
Amino acids are subunits of proteins. – Bond to a hydrogen atom, an amino group -NH2, an acidic group -COOH, and an R (remainder) group. ! Peptide Bond - Covalent bond between two amino acids. " Peptide - Two or more amino acids bonded together. " Polypeptide - Chain of many amino acids joined by peptide bonds.
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Proteins
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Protein Folding Diseases
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Protein Structure – Primary - Sequence of amino acids. – Secondary - Polypeptide coils or folds in a particular fashion. – Tertiary - Folding and twisting that results in final three-dimensional shape of a polypeptide. – Quaternary - Consists of more than one polypeptide.
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As proteins are being synthesized, chaperones bind and prevent incorrect interactions. – Mad cow disease is an example of a category of fatal brain diseases TSEs, that could be due to misfolded proteins.
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Nucleic Acids
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DNA
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Polymers of nucleotides with very specific cell functions. – DNA (seoxyribonucleic acid) ! Doublestranded – RNA (ribonucleic acid) ! Singlestranded Every nucleotide is made up of phosphate, pentose sugar, and a nitrogenous base. – Complementary base pairing
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RNA
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Nucleic Acids ATP (adenosine triphosphate) is composed of adenine and ribose. – In cells, the terminal phosphate bond is hydrolyzed to give the molecule ADP (adenosine diphosphate) and a phosphate molecule. ! Releases energy
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Review
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Organic vs Inorganic Functional Groups and Isomers Macromolecules – Carbohydrates – Lipids – Proteins – Nucleic Acids
Mader: Biology 8th Ed.
Mader: Biology 8th Ed.
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