Post on 25-Dec-2015
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Ch 3: Biomolecules
Ch 3: Biomolecules
• Organic compounds ? contain– Carbon Based
• Very Diverse Group ? 4 major– H,O,N,C….leads to millions of types of molecules
• Carbon has 4 Valence electrons– So can covalently bond to? – Up to 4 elements, including itself– When with H…
Reasons For Diversity:
1. Can Bond with other Carbons to form….– Chains
– Branched Chains
– Rings
Ring Structure
• Aromatic Compounds= Double bond somewhereEx: Benzene C6H6
Ring Structure
• Aliphatic Compounds= Only Single Bonds
Ex: Cyclohexane C6H12
Reasons For Diversity:
2. Varied Bonding Patterns(Single, double, triple)
Hydrocarbons• Alkane Single• Alkene Double• Alkyne Triple
Reasons For Diversity:
3. Biomolecules exist as isomers.
Same molecular formula, different structural formulaImportance in Biology?
FORM DRIVES FUNCTION!!
Reasons For Diversity:
3. Biomolecules exist as isomers. C5H12
Same molecular formula, different structurally = different properties
P/S: 4 main macromolecules, and their monomers?
• Proteins– Amino Acids (20)
• Nucleic Acids– Nucleotides– DNA/RNA
• Carbohydrates– Monosaccharides– Sugars
• Lipids– Fatty Acids
Reasons For Diversity:
4. Functional Groups– Adds to the diversity of biomolecules by replacing
an H atom or a methyl group (-CH3)– Ex: Hydrocarbon vs alcohol
Reasons For Diversity:
4. Functional Groups Provides a “Fingerprint” which classifies a compound Helps to “Predict” how compounds will act in a
chemical reaction Makes molecules more reactive Where new bonds are formed and broken
WHERE THE ACTION IS!
Carbonyl C=O
Carbohydrates• C,H,O 2:1• Energy!• Sugars ‘___ose’‘simple’ = MonosaccharidesDisaccharides (sucrose)
Polysaccharides – Storage: Starch, glycogen, Structure: cellulose
chitin- exoskeleton
Carbohydrate Functional Groups?
Hydroxyl (-OH) Carbonyl (-C=O) Hexose, Pentose, Triose
Glycosidic Linkages:
http:http://Formation of a disaccharide
Dehydration Synthesis
Dehydration synthesis vs. hydrolysis
Alpha vs Beta Glucose
• 1-4 linkage
animation
Lipids
• Composition? • Functional Group?
• C,H,O *No Ratio H:O • Carboxyl -COOH
• Long term storage of energy• Component of cell membrane structure• Protective surface coating (plant cuticle)• Insulation; nerve function (Animals)• Basis for many hormones
Waxes Phospholipids Steroids Fats and Oils (triglycerides)
• Natural…fyi• Anabolic..fyi
Steroids
4 interconnected rings
*MAJOR component of all cell membranes “phopholipid bilayer”
HydrophobicHydrophilic
Amphipathic "amphi" = "both“ - dual nature -polar/non-polar)
Phospholipid vsTriglycerideStructure
Ester Linkages Hydroxyl-carboxyl connection
Formation of a triglyceride
H2O
(All single)
• Solid at room temp (Animal fats) tightly packed
• Liquid at room temp (Plant, fish fats- aka oils) ‘kinks’ in the structure
• Most complex• Primary elements?• C, H, O, ****N
• Functional groups? • Carboxyl –COOH• Amine -NH2
• *Functions*• *Forms*• Building Blocks: Amino Acids- 20 common amino acids
Proteins
• http://www.biotopics.co.uk/as/aminocon.html
Peptide Linkages
LEVELS of PROTEIN STRUCTURE
1 2 3 4
Peptide bonds Alpha,Beta Di-sulfide Bridges 4+ Tertiary Forms H-bonds R-group Interaction
Protein Structure and Function
• Structural framework• Storage• Movement: cellular
and body• Metabolism/
Catalysis(Enzymes-Hormones)
• Transport• Body Defense
Beta
Globular and Fibrous Proteins Fibrous ProteinsLittle or no tertiary structure.Long parallel polypeptide chains.Cross linkages at intervals forming long fibres or sheets.Usually insoluble.Many have structural roles.E.x- keratin in hair and the outer layer of skin, collagen (a connective tissue). -Actin/Myosin- movement
Globular ProteinsHave complex tertiary and sometimes quaternary structures.Folded into spherical (globular) shapes.Roles in metabolic reactions.E.g.- enzymes, hemoglobin, insulin. -antibodies/defense
Denatured Protein
The Amino Acids
• R-group- changes the shape and the function
Nucleic Acids
Phosphodiester Linkage