ATP$Synthase!1$Outline$§ Proton4Mo6ve$Force$hypothesis$§ ATP$synthase:$$Composi6ons,$how$it$works.$§ P/O$ra6o$and$the$final$ATP$count$§ ShuEle$systems$§ Uncouplers$of$oxida6on$p hos pho ryla6on$2$Oxida6ve$Phosphoryla6on$3$Chemiosmo6c$Hypothesis$By$Peter$Mitchell$(1961)$4$Racker$and$Stoeckenius$Confirmed$the$Mitchell$Model$5$Matrix$Intermembrane$Space$$Inner$membrane$ATP$Synthase$/$Complex$V$ADP$+$Pi$$ATP$6$The$F1$Por6on$of$the$ATP$Synthase$behaves$as$an$ATPase$when$dissociated$from$the$F0$subunit.$7$L!View$of$the$ATP$Synthase$from$the$Top$(matrix4side)$8$hEp://guweb2.gonzaga.edu/faculty/cronk/chemistry/chem445/lectures.cfm?L=6$Subunit$1:$LèTèOèLèTèO$Subunit$2:$OèLèTèOèLèT$Subunit$3:$TèOèLèTèOèL$Rota6on$of$the$γ$subunit$drives$the$$conforma6onal$change$of$the$β$subunits.$9$Components$of$the$proton4conduc6ng$unit$of$ATP$synthase$H+!H+!H+!H+!H+!H+!H+!H+!Matrix!half.channel!H+!H+$H+$H+$H+$Asp61$H+$H+$Asp61$10$Proton$path$through$the$membrane.$$Intermembrane$space$matrix$H+!H+!H+!H+!H+!H+!Rota4on!driven!by!proton!concentra4on!11$Ferris$Wheel$at$Navy$Pier$12$The$ATP4ADP$translocase$enables$the$exchange$of$cytoplasmic$ADP$for$mitochondrial$ATP.$13$Pi$also$need$to$be$translocated$to$the$matrix$Generates$H2O,$removing$one$H+$from$Intermembrane$space.$Adds$one$proton$to$the$cost$of$synthesizing$each$ATP.$matrix$H+$+$H2O$14$1$NADH$=$10$protons$out=$2.5$ATP$$1$FADH2=$6$protons$out$=$1.5$ATP$ATP$synthase$:$9$subunits$uses$9$protons$=$3$ATP$$(3$protons/ATP)$$Import$of$1$Pi$:$$uses$1$proton$$(1$Pi$to$make$1$ATP)$Need$4$protons$to$make$1$ATP$Why$does$FADH2$generate$less$ATP$than$NADH2?$The$P/O$ra6o$15$Pyruvate4AcetylCoA:$$$ $2$NADH$ATP$Yield$p er$ molecule$of$gl u cose$Glycolysis:$$ $ $$$$2$net$ATP$$$$$$$$$2$NADH$TCA: $$$ $ $$$$$2$ATP/GTP$$$$$$$$$6$NADH$$$$$$$$$2$FADH2$Oxida6ve$Respira6on:$ $$$ $each$NADH$=$2.5$ATP $ $$15$ATP$$each$FADH2$=$1.5$ATP$ $$3$ATP$Grand$Total$of$ATP$=$30$$3$ATP$5$ATP$*$*$Will$vary$between$6ssues$P/O!!16$pyruvate$How$are$NADH$molecules$from$Glycolysis$moved$to$Inner$Membrane?$17$Cytosolic$NADH$can$enter$the$ETC$$via$the$Glycerolphosphate$ShuEle$$This$shuEle$operates$in$the$skeletal$muscle$and$brain.$Inner$mitochondrial$membrane$18$Glycerol$34Phosphate$ShuEle$19$Cytosolic$NADH$enters$the$ETC$$via$the$Malate4Aspartate$ShuEle$This$shuEle$operates$in$the$liver,$kidney$and$heart$mitochondria.$aminotransferase$aminotransferase$20$Malate$–Aspartate$ShuEle$21$The$rate$of$oxida6ve$respira6on$is$determined$by$the$need$for$ATP$22$$The$energy$charge$regulates$the$use$of$fuels$23$Uncoupling$Protein$1$(UCP41)$/$thermogenin$Matrix$24$Brown$Fat$(Thermogenesis)$25$$Brown$adipose$6ssue$is$revealed$on$exposure$to$cold.$26$Ac6va6ng$Beige$Fat$$An$innate$immune$pathway$s6mulates$the$ac6vity$of$heat4producing$adipose$6ssue$in$mice.$$By$Kerry$Grens$|$June$5,$2014$$R.R.$Rao$et$al.,$“Meteorin4like$is$a$hormone$that$regulates$immune4adipose$interac6ons$to$increase$beige$fat$thermogenesis,”$Cell,$doi:10.1016/j.cell.2014.03.065,$2014.$$Y.$Qiu$et$al.,$“Eosinophils$and$type$2$cytokine$signaling$in$macrophages$orchestrate$development$of$func6onal$beige$fat,”$Cell,$doi:10.1016/j.cell.2014.03.066,$2014.$27$Non4physiological$chemical$uncouplers$Matrix$2,4,4dinitrophol$(DNP)$H+$H+$H+$H+$H+$28$Learning$Goals$• Be$able$to$describe$how$the$proton4mo6ve$force$is$converted$into$ATP$• Know$the$two$major$shuEle$systems$for$electron$carriers$and$the$mitochondrial$transporters$•
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