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Chapter 3. Molecules of Life. Organic compounds. Always contain carbon Always have covalent bonds (not ionic) Usually associated with large numbers of atoms Commonly associated with living things. carbon. Can covalently bond with as many as 4 other atoms Can form many shapes.
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Chapter 3 Molecules of Life
Organic compounds • Always contain carbon • Always have covalent bonds (not ionic) • Usually associated with large numbers of atoms • Commonly associated with living things
carbon • Can covalently bond with as many as 4 other atoms • Can form many shapes
Carbon Compounds • Carbohydrates • Lipids • Proteins • Nucleic Acids
Building compounds • Monomer—individual building unit • Polymer—many units covalently bonded
Building compounds • Functional groups—atoms or clusters of atoms covalently bonded to organic compounds that affect the compound’s structure and fuction
Reaction categories • Mediated by enzymes (special proteins) • Fuctional-group transfer • Electron transfer • Rearrangement • Condensation • Cleavage
condensation • Split OH- from one molecule • Split H+ from another molecule • Bonds form at exposed sites • Water is byproduct
hydrolysis • Reverse of condensation • Split molecules • Add OH- and H+ from water
carbohydrates • Monosaccharides • Single sugar unit • Soluble in water • Sweet taste • Hydroxyl group (OH-) • Used to assemble larger carbohydrates
carbohydrates • Oligosaccharide • Short chain of two or more sugar monomers • Disaccharide—2 units, simplest
carbohydrates • Polysaccharide—chain of hundreds or thousands of monomers • “Complex” carbohydrates • Starch—plant energy source • Cellulose—plant cell wall • Glycogen—animal muscle energy • Chitin—structural component of insects
lipids • Greasy or oily compounds • Non-polar, hydrophobic • Energy storage, membrane structure, coatings
Lipids • Fatty acids—long chain of mostly C and H with a carboxyl group (-COOH) at the end • Saturated—single Carbon bonds • Unsaturated—double Carbon bonds
Lipids • Fat—one or more fatty acids attached to glycerol • Twice the energy of carbohydrates • Insulation
Lipids • Phospolipid • 2 Fatty Acids + Phosphate Group + Glycerol • Main structural material of membranes
lipids • Sterols • 4 carbon rings, no fatty acid tails • Cholesterol, testosterone, estrogen
lipids • Waxes • Long-chain fatty acids + alcohols or carbon rings • Coatings for plant parts or animal coverings
Proteins • Most diverse of all biological molecules • Enzymes • Cell movement • Storage & transport • Hormones • Antibodies • Structure
proteins • Amino acid—monomer unit • Three groups covalently bonded to central C
proteins • Polypeptides—polymer of proteins
Proteins • Structure • Primary • Secondary • Tertiary • Quaternary
Proteins • Why is structure important? • Change in shape is VERY important to function
Nucleic acids • Nucleotide—monomer unit • 5-carbon sugar (ribose or deoxyribose) • Nitrogen base • Phosphate group
Nucleic acid • DNA—double-stranded helix, carries hereditary information • RNA—single-stranded helix, translates code to build proteins • ATP—single nucleotide, releases energy for cells to work
DNA & RNA • Large number of hydrogen bonds • Nitrogen bases: Adenine, Cytosine, Guanine, Thymine (Urasil)