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S 2007 BIOC 3406. 01-23-07. Three cleavage points for ATP. ROH + ATP ADP leaving group, ROPO 3 2- + ADP AMP leaving group, ROP 2 O 6 3- + AMP P 2 O 7 4- (PP i ) leaving group, adenosine-R ester product (R has been adenylylated). Adenylylation in the synthesis of DNA, RNA. NTP
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S 2007 BIOC 3406 01-23-07
Three cleavage points for ATP ROH + ATP • ADP leaving group, ROPO32- + ADP • AMP leaving group, ROP2O63- + AMP • P2O74- (PPi) leaving group, adenosine-R ester product (R has been adenylylated)
Adenylylation in the synthesis of DNA, RNA • NTP • ROH is polymer chain 3’ terminal ribose
K+ Na+ Active Xport • Na+/K+ ATPase • Moves Na+ across cell membranes • Na+ out and K+ in • Establishes electrical, chemical potential Na+ Higher potential Lower potential K+
Inorganic polyphosphate • 0.2 M in yeast vacuoles • Transport of H+ in plants • Prebiotic energy system
Biochemical Equations • More focused than ordinary • Often not balanced, either in charge OR atoms • Emphasizes substrate (often ignores enzyme) • Assumes pH 7 and 1mM Mg2+
Half-Reactions • Red Red+ + e- • Ox + e- Ox- • Total: Red + Ox Red+ + Ox-
Dehydrogenation • Transfer of H2 is a redox • Hydrogenation of a double bond • Hydrogenation across conjugated carbon chain
Reduction Potentials e- flow ion flow Red, Red+ Ox, Ox- Pt electrodes salt bridge anode cathode
Nernst E = E0 +(RT/nF)ln[(eln acceptor)/(electron donor) G ~ E G = -nFE
Electron carriers • NADH • FAD