BILD 1 Notes

BILD 1 Notes - BILD 1 Notes Lecture 2 Jan 5 - The four...

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BILD 1 Notes Lecture 2 – Jan 5 - The four major elements of life in organic compounds are H, O, C, N o Makes up 96% of living matter - Polar covalent bonds form when one electronegative element in a compound pulls electrons closer to itself o H2O is polar, while CH is nonpolar - Ionic bonds occur in interactions between DNA and proteins (cations and anions) o Transfer of electrons between atoms to form two ions bonded together NaCl forms crystal table salt (not a molecule but an ionic compound) - Hydrogen bonds play an important role in the formation of protein structures o Forms from H—O reactions between slightly positive H and negative Oxygen H is shared between polar molecules o Occurs with multiple H2O molecules and NH3 and H2O compounds o Water, because of its Hydrogen bonds becomes a good solvent that forms charged cages around ions that dissolve and break up ionic compounds and biological molecules that carry a chard like lysozymes and other enzymes and proteins - Hydrophilic substances – soluble in water, polar or charged (ionic) o NH3, NaCl, polar or charged parts of proteins - Hydrophobic substances-non-soluble in water, uncharged, non-polar o Lipids – dominant bonds are C-C and C-H with equal sharing of electrons Oils and fats - Van der Waals interactions occur with dipoles in phospholipids in a membrane o Allows geckos to climb walls from tiny hairs on their fingers o Relatively weak interactions, but can be strengthened by many molecules Lecture 3 – Jan 7 - pH = -log [H+], pOH = -log [OH-] o acids increases [H+] while bases increase [OH-] and reduces [H+] carbonic acid (CO(OH)2) donates an H+ ion and becomes a Bicarbonate ion (CO2OH)- This is known as a weak acid and is commonly found in the blood and keeps the pH of the blood to 7.4 (known as a buffer system) Strong Base – Sodium Hydroxide (NaOH) in aqueous solution dissociates immediately into sodium and hydroxide ions and increase [OH-] and decreases [H+] therefore raising the pH Bases can also act by absorbing H+ ions NH3 + H+ -> NH4+ (ammonium ion decreases [H+] and raises pH) - Organic Molecules o Carbon-based o Can be small to gigantic o Generally fall into 4 major groups Carbohydrates, lipids, nucleic acids, proteins o Vary in the structure of the carbon skeleton to form isotopes based on layout Can form rings like cyclohexane (C6H12) and benzene (C6H6)
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o Biological molecules contain other functional groups Cysteine and ATP (nucleotide) Carboxyl group ( COOH) Contained in all amino acids, makes them acids Amino group (NH2) Also contained in every amino acid Tends to work like ammonia as a weak base Sulfhydryl group (SH) Plays important role in maintaining shape of protein When two SH’s come together, they drop their hydrogens to form covalent bonds and hold things together
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This note was uploaded on 01/14/2012 for the course BILD 1 taught by Professor Boulanger during the Winter '08 term at UCSD.

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BILD 1 Notes - BILD 1 Notes Lecture 2 Jan 5 - The four...

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