Atoms, Molecules Atoms, Molecules and Macromolecules and Macromolecules Building Complex Building Complex Molecules That Molecules That Comprise Living Things Comprise Living Things Prof. Mary Colavito Prof. Mary Colavito & Dr. John Shepanski & Dr. John Shepanski
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Atoms, Molecules and Macromolecules Building Complex Molecules That Comprise Living Things Prof. Mary Colavito & Dr. John Shepanski.
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Atoms, Molecules Atoms, Molecules and Macromolecules and Macromolecules
Building Complex Molecules Building Complex Molecules That Comprise Living ThingsThat Comprise Living Things
Prof. Mary ColavitoProf. Mary Colavito& Dr. John Shepanski& Dr. John Shepanski
Comparison of Terms Comparison of Terms
ElementElement Substance that cannot be broken down Substance that cannot be broken down to another substance with different to another substance with different propertiesproperties
AtomAtom Smallest unit that has characteristic Smallest unit that has characteristic properties of the elementproperties of the element
MoleculeMolecule Two or more atoms joined by chemical Two or more atoms joined by chemical bondsbonds
MacromoleculeMacromolecule Large polymer made of monomer unitsLarge polymer made of monomer units
Number of electrons = Number of protons Number of electrons = Number of protons
Each electron circles the nucleus in an orbitEach electron circles the nucleus in an orbitrepresenting a specific energy level.representing a specific energy level.
33 18 (8*)18 (8*)*In forming molecules, atoms combine to fill their outer *In forming molecules, atoms combine to fill their outer ((valencevalence) energy levels. When 8 valence orbitals are ) energy levels. When 8 valence orbitals are filled, remaining, unused slots available in inner levels filled, remaining, unused slots available in inner levels are filled before a new valence shell is added.are filled before a new valence shell is added.
Chemical BondsChemical Bonds
BondBond CharacteristicsCharacteristics
IonicIonic One atom loses an electron, One atom loses an electron, another gains an electronanother gains an electron
Covalent BondingCovalent BondingOxygen AtomOxygen Atom Oxygen AtomOxygen Atom
Oxygen Molecule (O2)
In Water, Polar Covalent Bonds In Water, Polar Covalent Bonds Join Oxygen and Hydrogen Join Oxygen and Hydrogen
Hydrogen Bonds Join Water MoleculesHydrogen Bonds Join Water Molecules
OO
OO
HH
HH
HHHH+
+
+
–
–
+
+
HydrogenHydrogenBondsBonds
Water molecules Water molecules are dipoles—the are dipoles—the hydrogen side is hydrogen side is more positive; more positive; the oxygen side the oxygen side is more negativeis more negative
Hydrogen bonds Hydrogen bonds form between O form between O of one water of one water molecule and H molecule and H of another of another
Due to hydrogen bonding, ionic and Due to hydrogen bonding, ionic and polar substances dissolve in waterpolar substances dissolve in water
HydrophobicHydrophobic Not attracted to waterNot attracted to water& non-polar substances& non-polar substances
HydrophilicHydrophilic Attracted to water,Attracted to water,polar and ionic substancespolar and ionic substances
Each carbon atom can make fourEach carbon atom can make fourcovalent bonds with other types of covalent bonds with other types of atoms or additional carbons.atoms or additional carbons.
Macromolecules: Polymers Macromolecules: Polymers Made of Repeating MonomersMade of Repeating Monomers
MacromoleculeMacromolecule Monomer UnitMonomer Unit
CarbohydratesCarbohydrates SugarsSugars
LipidsLipids Fatty acidsFatty acids
ProteinsProteins Amino acidsAmino acids
Nucleic AcidsNucleic Acids NucleotidesNucleotides
Synthesis and Breakdown of Synthesis and Breakdown of Macromolecules Macromolecules
Condensation Condensation SynthesisSynthesis
Removal of water to add Removal of water to add monomer unitsmonomer units
HydrolysisHydrolysis Addition of OH and H Addition of OH and H groups of water to break groups of water to break a bond between a bond between monomersmonomers
• Phospholipid—Phospholipid—component of cell membranescomponent of cell membranes
Lipids: StructureLipids: Structure• Types of Fatty Acids Types of Fatty Acids
– Saturated – 2H per internal carbonSaturated – 2H per internal carbon
– Unsaturated -- <2H per internal carbon Unsaturated -- <2H per internal carbon one or more double bondsone or more double bonds• Monounsaturated – one double bondMonounsaturated – one double bond
• Polyunsaturated – more than one double bond Polyunsaturated – more than one double bond
Which Is a Source of Unsaturated Fatty Acids?Which Is a Source of Unsaturated Fatty Acids?
Linseed OilLinseed OilBeef Fat Beef Fat
Lipids: FunctionsLipids: Functions• Concentrated energy sourceConcentrated energy source• Structural components of cell membranesStructural components of cell membranes
•Each chain is used Each chain is used as a pattern to as a pattern to produce a new chain produce a new chain
•Each new DNA helix Each new DNA helix contains one “old” contains one “old” and one “new” chain and one “new” chain
Transcription = Production of RNA UsingTranscription = Production of RNA Using DNA as a Template DNA as a Template
•DNA chains separateDNA chains separate
•ONE DNA chain is used ONE DNA chain is used as a pattern to produce as a pattern to produce an RNA chain an RNA chain
•RNA chain is releasedRNA chain is released and the DNA chains and the DNA chains reform the double-helix reform the double-helix
In DNA In RNA A U T A G C C G
Transcription Transcription Protein Synthesis Protein Synthesis
• Messenger RNAMessenger RNAContains the code words for Contains the code words for the sequence of amino acids the sequence of amino acids in a specific proteinin a specific protein
CODON = group of three CODON = group of three nucleotides acting as a code nucleotides acting as a code word for a protein amino acidword for a protein amino acid
• At sub-cellular structures At sub-cellular structures called ribosomes, RNA code called ribosomes, RNA code is used to guide the assembly is used to guide the assembly of proteinsof proteins
Four Levels of Protein StructureFour Levels of Protein Structure
PrimaryPrimary(Sequence)(Sequence)
PrimaryPrimary(Sequence)(Sequence)
SecondarySecondary(Coiling by (Coiling by
Hydrogen Bonding)Hydrogen Bonding)
SecondarySecondary(Coiling by (Coiling by
Hydrogen Bonding)Hydrogen Bonding)
TertiaryTertiary(Folding by (Folding by
R-group R-group interactions)interactions)
TertiaryTertiary(Folding by (Folding by
R-group R-group interactions)interactions)
QuaternaryQuaternary(Two or more chains (Two or more chains
associating)associating)
QuaternaryQuaternary(Two or more chains (Two or more chains
associating)associating)
Proteins: StructureProteins: Structure
AminoAminoGroup Group
The “R” GroupThe “R” GroupDiffers for Each Amino AcidDiffers for Each Amino Acid
Carboxylic AcidCarboxylic AcidGroupGroup
CentralCentralCarbonCarbon
RR
• Primary structure = chain of amino acidsPrimary structure = chain of amino acids– Amino acids have common featuresAmino acids have common features
Proteins: StructureProteins: Structure Forming the Protein ChainForming the Protein Chain
Dehydration Synthesis between COOH & NH2
PhenylalaninePhenylalanine LeucineLeucine
Secondary structuregoverned by hydrogen bonds
Tertiary structure governed byattraction/repulsion of R-groups
Four Levels of Protein StructureFour Levels of Protein Structure
• Quaternary Structure:Quaternary Structure:
Association of two or more protein Association of two or more protein chains chains
eg. eg. HemoglobinHemoglobin is composed is composed of 4 protein chains of 4 protein chains
2 are called alpha 2 are called alpha hemoglobin hemoglobin
2 are called beta 2 are called beta hemoglobin hemoglobin