Outline of Last LectureOutline of Current LectureCurrent LectureI. Carbona. Propertiesb. Hydrocarbonsi. ISOMERSii. Functional Groups:BIO SCI 150 1st Edition Lecture 3Outline of Last Lecture I. Watera. Propertiesb. Key termsc. Bondsd. Solutionsi. Molesii. Acids & Bases1. The pH scaleOutline of Current Lecture II. Carbona. Propertiesb. Hydrocarbonsi. Isomersii. Functional GroupsCurrent LectureI. Carbona. Properties- Carbon, Atom of Life- Carbon is the most abundant element in the dry weight of a cell:o C=50% O=20% H=10% N=10% P=4% S=l%- Carbon has an atomic structure that makes it an ideal building block.o Structure: 4 valence electrons can form 4 single bonds- Carbon is less electronegative than Oxygen or Nitrogen and “shares electrons”.Methane CH4EthaneC2H6EthanolC2H5OHEtheneC2H4b. HydrocarbonsCarbon can form numerous structures that vary in: Number of Carbon atoms Other atoms present Presence of a double bondDefinition: Compounds containing Carbon and Hydrogen. Since neither carbon nor hydrogen is very electronegative, these compounds are rich in electrons that can be “taken” by oxygen. Hydrocarbons are often energy-rich fuels. Can be simple Hydrocarbons may be long chains, and may form rings withor without doublei. ISOMERS Definition: The same formula may give different structures depending upon the spatial arrangement of the atoms Structural isomers: covalent arrangement of atoms Geometric isomers: arrangement of atoms around double bond; since the double bond does not rotate easily this canproducedifferent structures with different properties Stereoisomers 4 different groups attached to a single (asymmetric) carbon can exist in two different 3-Dimensional arrangements, like left and right hands, or mirror imagesii. Functional Groups: Other atoms. O, N, P, S, which bond to the hydrocarbon skeleton. These give unique properties to the molecule. Hydroxyl –OH Polar, present in sugars and alcohols Carbonyl C=O double bond O to C aldehyde - at end of chain ketone - not at end Carboxyl- double bond O, and OH to same Carbon form carboxylic acids OH can donate H+ because 2 oxygen “pull” electron Amino C-N amines ionized This group is present in the amino acid of proteins Amino group acts as base, accepts a hydrogen ion H+ Sulfhydryl C-SH Thiol important in protein structure Phosphate Involved in energy storage and transfer Used by living; systems to alter the properties of protein when added. Phosphorylation is often seen in signal transduction
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