Given: Aerobic growth of S. cerevisiae on ethanol is simply described by the following overall reaction Explanation: Simple elemental balance on C,H,O and N yeild the following equation C:2(1)=c(1)+d(1)=c+d H:5(1)+1(1)+b(3)6+3b=c(1.704)+e(2)=1.704c+2e O:1(1)+a(2)1+2a=c(0.408)+d(2)+e(1)=0.408c+2d+e H:bb(1)=0.149cc(0.149) The respiratory quotient (RQ) 0.66=d/ad=0.66a2=c+0.66a6+3(0.149c)=1.704c+2e 6=1.257c+2e 6=1.257(20.66a)+2e 3.486=2e0.830a 1+2a=0.408(20.66a)+2(0.66a)+1e 0.184=1e0.949a 0.408(20.66a)+2(0.66a)+1e1e0.949a (9)20.368=2e1.898a 3.118=1.068a a=2.919 d=0.66(2.919) d=1.926 2=c+1.926 c=0.074 b=0.149(0.074) b =0.011 6+3(0.011)==1.704(0.074)+2e e=2.953 C: 2=c+d2=0.074+1.9262=2 H:6+3(0.011)6.0336+3b=1.704(0.074)+2(2.953)=6.032=1.704c+2e O:1+2a1+2(2.919)6.838=0.408c+2d+e=0.408(0.074)++2.953=6.835 N:b=0.149c0.011=0.149(0.074)0.011=0.011RQ:d=0.66a1.926=0.66(2.919)1.926=1.926 b) Molecular Weight Biomass, Substrate O2 C=12H=1O=16N=14 MW Biomass (x) CH(1.704)N(0.14900(0.408)=1(12)+1.704(1)+0.149(14)+0.408(16) MW Substrate (s =22.318 C2H5OHMWO2=2(12)=32 Biomass(YX/s) Yx/sYxx/O2=x/s=cMwbiomass/1MwC2H3OH=0.036gdwcells/gethanol=x/O2=cMwbiomass/aMw(O2)=0.07422.318/2.91946