breed [ enzymes enzyme] breed [ substrates substrate] breed [ products product] turtles-own [complexing?] to setup ca set-current-plot "Amounts" clear-plot create-substrates 100 [ set shape "substrate" set color red] create-enzymes 20 [set shape "enzyme"] ask turtles [setxy random-xcor random-ycor set complexing? false] end to setup_system set-current-plot "SystemModel" clear-plot system-dynamics-setup end to go_system system-dynamics-go system-dynamics-do-plot end to go tick ask turtles [move ] ask enzymes [ if not complexing? [form-complex ] ] ask enzymes [ if complexing? [dissociate] ] ask enzymes [if complexing? [form-product] ] plot-amounts end to move fd 1 rt random-float 360 end to form-complex let partner 0 if any? substrates-here and random-float 100 < Kfwd1 [ set complexing? true set partner one-of substrates-here if not [complexing?] of partner [ask partner [die] set shape "complex" ] ] end to form-product if random-float 100 < Kfwd2 [set complexing? false set shape "enzyme" hatch-products 1 [set shape "product"] ] end to dissociate if random-float 100 < Krev1 [set complexing? false set shape "enzyme" hatch-substrates 1 [set shape "substrate"] ] end to plot-amounts set-current-plot "Amounts" set-current-plot-pen "Substrate" plot count substrates set-current-plot-pen "Enzyme" plot count enzymes with [not complexing?] set-current-plot-pen "Complex" plot count enzymes with [complexing?] set-current-plot-pen "Product" plot count products end @#$#@#$#@ GRAPHICS-WINDOW 306 10 687 412 12 12 14.84 1 10 1 1 1 0 1 1 1 -12 12 -12 12 1 0 1 ticks CC-WINDOW 5 531 1022 626 Command Center 0 BUTTON 53 31 117 64 setup setup NIL 1 T OBSERVER NIL NIL NIL NIL BUTTON 126 31 187 64 go go T 1 T OBSERVER NIL NIL NIL NIL SLIDER 51 142 205 175 Kfwd2 Kfwd2 0.0 100.0 45 1.0 1 NIL HORIZONTAL SLIDER 51 72 205 105 Kfwd1 Kfwd1 0.0 100.0 45 1.0 1 NIL HORIZONTAL SLIDER 51 107 205 140 Krev1 Krev1 0.0 100.0 16 1.0 1 NIL HORIZONTAL PLOT 3 181 306 414 Amounts time C 0.0 50.0 0.0 50.0 true true PENS "Substrate" 1.0 0 -2674135 true "Complex" 1.0 0 -8630108 true "Product" 1.0 0 -13345367 true "Enzyme" 1.0 0 -16777216 true BUTTON 747 31 856 64 NIL setup_system NIL 1 T OBSERVER NIL NIL NIL NIL BUTTON 862 31 954 64 NIL go_system T 1 T OBSERVER NIL NIL NIL NIL PLOT 690 201 1013 410 SystemModel time Amounts 0.0 10.0 0.0 1.0 true true PENS "Substrate2" 0.05 0 -2674135 true "Enzyme2" 1.0 0 -16777216 true "ES" 1.0 0 -8630108 true "Product2" 1.0 0 -13345367 true TEXTBOX 89 14 239 32 Agent Model 11 0.0 0 TEXTBOX 824 14 974 32 Systems model 11 0.0 0 BUTTON 355 443 472 476 Setup Compare setup\nsetup_system NIL 1 T OBSERVER NIL NIL NIL NIL BUTTON 483 444 592 477 Compare go\nset-current-plot \"SystemModel\"\ngo_system T 1 T OBSERVER NIL NIL NIL NIL TEXTBOX 387 419 603 437 Compare the Agent and System model 11 0.0 0 SLIDER 746 73 918 106 forward_rate_1 forward_rate_1 0 2 1 .1 1 NIL HORIZONTAL SLIDER 746 113 918 146 reverse_rate_1 reverse_rate_1 0 1 0.3 0.05 1 NIL HORIZONTAL SLIDER 746 156 918 189 forward_rate_2 forward_rate_2 0 2 1 .1 1 NIL HORIZONTAL BUTTON 57 440 185 473 watch an enzyme watch one-of enzymes NIL 1 T OBSERVER NIL NIL NIL NIL BUTTON 84 484 147 517 reset rp NIL 1 T OBSERVER NIL NIL NIL NIL @#$#@#$#@ WHAT IS IT? ----------- This model demonstrates the kinetics of single-substrate enzyme-catalysis. This model allows the user to compare an agent model and a system model. The standard equation for this reaction is shown below. | Kfwd1 Kfwd2 | E + S <=======> E-S ------> E + P | Krev1 Here E represents Enzyme, S Substrate, E-S Enzyme-Substrate complex, and P product. The rate constants are Kfwd1 for complex formation, Krev1 for complex dissociation, Kfwd2 for catalysis and product formation. The first step in catalysis is the formation of the E-S complex. The rates of complex formation and dissociation are very fast because they are determined by collision and separation of the molecules. The next step is for the enzyme to catalyze the conversion of substrate to product. This rate is much slower because the energy required for catalysis is much higher than that required for collision or separation. HOW TO USE IT -------------- Choose the values of Kfwd1, Krev1, and Kfwd2 with appropriate sliders: - Kfwd1 controls the rate at which substrates (red) and enzymes (yellow) stick together so that catalysis can occur - Krev1 controls the rate at which they come unstuck - Kfwd2 controls the rate of the forward reaction by which an enzyme converts a substrate to a product (blue) Having chosen appropriate values of the constants, press SETUP to clear the world and create a constant initial number of enzyme molecules. Play with several different values to observe variable effects on complex formation and catalysis. Press GO to start the simulation. The concentrations of enzyme, substrate, complex, and product are plotted in the AMOUNTS window. On the systems side, choose values for each of the rate constants and run the model. Finally, compare the two models and attempt to find the appropriate combination of rate constants which give comparable behavior. THINGS TO NOTICE ---------------- Watch the rate at which the enzyme and substrate stick together. How does this affect the conversion of substrate into product? What would happen if Krev1 is very high and Kfwd1 is very low? If Kfwd2 is of the same order of magnitude as Kfwd1 and Krev1? THINGS TO TRY ------------- If Kfwd2 is MUCH greater than Krev1, what affect does this have on the reaction? How important does complex formation become in this situation? If Kfwd1 is MUCH less than Krev2, what does this mean in the real-world? How are the enzyme and substrate related under these conditions? EXTENDING THE MODEL ------------------ Include a slider that allows you to change the concentration of substrate and/or enzyme. What affect does this have on the plot? NETLOGO FEATURES ------------------ This model features the "docking" of an agent model and a systems model. CREDITS AND REFERENCES ---------------------- NetLogo. http://ccl.northwestern.edu/netlogo/. Center for Connected Learning and Computer-Based Modeling, Northwestern University, Evanston, IL. @#$#@#$#@ default true 0 Polygon -7500403 true true 150 5 40 250 150 205 260 250 airplane true 0 Polygon -7500403 true true 150 0 135 15 120 60 120 105 15 165 15 195 120 180 135 240 105 270 120 285 150 270 180 285 210 270 165 240 180 180 285 195 285 165 180 105 180 60 165 15 arrow true 0 Polygon -7500403 true true 150 0 0 150 105 150 105 293 195 293 195 150 300 150 box false 0 Polygon -7500403 true true 150 285 285 225 285 75 150 135 Polygon -7500403 true true 150 135 15 75 150 15 285 75 Polygon -7500403 true true 15 75 15 225 150 285 150 135 Line -16777216 false 150 285 150 135 Line -16777216 false 150 135 15 75 Line -16777216 false 150 135 285 75 bug true 0 Circle -7500403 true true 96 182 108 Circle -7500403 true true 110 127 80 Circle -7500403 true true 110 75 80 Line -7500403 true 150 100 80 30 Line -7500403 true 150 100 220 30 butterfly true 0 Polygon -7500403 true true 150 165 209 199 225 225 225 255 195 270 165 255 150 240 Polygon -7500403 true true 150 165 89 198 75 225 75 255 105 270 135 255 150 240 Polygon -7500403 true true 139 148 100 105 55 90 25 90 10 105 10 135 25 180 40 195 85 194 139 163 Polygon -7500403 true true 162 150 200 105 245 90 275 90 290 105 290 135 275 180 260 195 215 195 162 165 Polygon -16777216 true false 150 255 135 225 120 150 135 120 150 105 165 120 180 150 165 225 Circle -16777216 true false 135 90 30 Line -16777216 false 150 105 195 60 Line -16777216 false 150 105 105 60 car false 0 Polygon -7500403 true true 300 180 279 164 261 144 240 135 226 132 213 106 203 84 185 63 159 50 135 50 75 60 0 150 0 165 0 225 300 225 300 180 Circle -16777216 true false 180 180 90 Circle -16777216 true false 30 180 90 Polygon -16777216 true false 162 80 132 78 134 135 209 135 194 105 189 96 180 89 Circle -7500403 true true 47 195 58 Circle -7500403 true true 195 195 58 circle false 0 Circle -7500403 true true 0 0 300 circle 2 false 0 Circle -7500403 true true 0 0 300 Circle -16777216 true false 30 30 240 complex true 0 Rectangle -1184463 true false 90 60 270 240 Circle -2674135 true false 9 69 162 cow false 0 Polygon -7500403 true true 200 193 197 249 179 249 177 196 166 187 140 189 93 191 78 179 72 211 49 209 48 181 37 149 25 120 25 89 45 72 103 84 179 75 198 76 252 64 272 81 293 103 285 121 255 121 242 118 224 167 Polygon -7500403 true true 73 210 86 251 62 249 48 208 Polygon -7500403 true true 25 114 16 195 9 204 23 213 25 200 39 123 cylinder false 0 Circle -7500403 true true 0 0 300 dot false 0 Circle -7500403 true true 90 90 120 enzyme true 0 Rectangle -1184463 true false 75 60 270 240 Circle -16777216 true false -31 59 182 face happy false 0 Circle -7500403 true true 8 8 285 Circle -16777216 true false 60 75 60 Circle -16777216 true false 180 75 60 Polygon -16777216 true false 150 255 90 239 62 213 47 191 67 179 90 203 109 218 150 225 192 218 210 203 227 181 251 194 236 217 212 240 face neutral false 0 Circle -7500403 true true 8 7 285 Circle -16777216 true false 60 75 60 Circle -16777216 true false 180 75 60 Rectangle -16777216 true false 60 195 240 225 face sad false 0 Circle -7500403 true true 8 8 285 Circle -16777216 true false 60 75 60 Circle -16777216 true false 180 75 60 Polygon -16777216 true false 150 168 90 184 62 210 47 232 67 244 90 220 109 205 150 198 192 205 210 220 227 242 251 229 236 206 212 183 fish false 0 Polygon -1 true false 44 131 21 87 15 86 0 120 15 150 0 180 13 214 20 212 45 166 Polygon -1 true false 135 195 119 235 95 218 76 210 46 204 60 165 Polygon -1 true false 75 45 83 77 71 103 86 114 166 78 135 60 Polygon -7500403 true true 30 136 151 77 226 81 280 119 292 146 292 160 287 170 270 195 195 210 151 212 30 166 Circle -16777216 true false 215 106 30 flag false 0 Rectangle -7500403 true true 60 15 75 300 Polygon -7500403 true true 90 150 270 90 90 30 Line -7500403 true 75 135 90 135 Line -7500403 true 75 45 90 45 flower false 0 Polygon -10899396 true false 135 120 165 165 180 210 180 240 150 300 165 300 195 240 195 195 165 135 Circle -7500403 true true 85 132 38 Circle -7500403 true true 130 147 38 Circle -7500403 true true 192 85 38 Circle -7500403 true true 85 40 38 Circle -7500403 true true 177 40 38 Circle -7500403 true true 177 132 38 Circle -7500403 true true 70 85 38 Circle -7500403 true true 130 25 38 Circle -7500403 true true 96 51 108 Circle -16777216 true false 113 68 74 Polygon -10899396 true false 189 233 219 188 249 173 279 188 234 218 Polygon -10899396 true false 180 255 150 210 105 210 75 240 135 240 house false 0 Rectangle -7500403 true true 45 120 255 285 Rectangle -16777216 true false 120 210 180 285 Polygon -7500403 true true 15 120 150 15 285 120 Line -16777216 false 30 120 270 120 leaf false 0 Polygon -7500403 true true 150 210 135 195 120 210 60 210 30 195 60 180 60 165 15 135 30 120 15 105 40 104 45 90 60 90 90 105 105 120 120 120 105 60 120 60 135 30 150 15 165 30 180 60 195 60 180 120 195 120 210 105 240 90 255 90 263 104 285 105 270 120 285 135 240 165 240 180 270 195 240 210 180 210 165 195 Polygon -7500403 true true 135 195 135 240 120 255 105 255 105 285 135 285 165 240 165 195 line true 0 Line -7500403 true 150 0 150 300 line half true 0 Line -7500403 true 150 0 150 150 link true 0 Line -7500403 true 150 0 150 300 link direction true 0 Line -7500403 true 150 150 30 225 Line -7500403 true 150 150 270 225 pentagon false 0 Polygon -7500403 true true 150 15 15 120 60 285 240 285 285 120 person false 0 Circle -7500403 true true 110 5 80 Polygon -7500403 true true 105 90 120 195 90 285 105 300 135 300 150 225 165 300 195 300 210 285 180 195 195 90 Rectangle -7500403 true true 127 79 172 94 Polygon -7500403 true true 195 90 240 150 225 180 165 105 Polygon -7500403 true true 105 90 60 150 75 180 135 105 plant false 0 Rectangle -7500403 true true 135 90 165 300 Polygon -7500403 true true 135 255 90 210 45 195 75 255 135 285 Polygon -7500403 true true 165 255 210 210 255 195 225 255 165 285 Polygon -7500403 true true 135 180 90 135 45 120 75 180 135 210 Polygon -7500403 true true 165 180 165 210 225 180 255 120 210 135 Polygon -7500403 true true 135 105 90 60 45 45 75 105 135 135 Polygon -7500403 true true 165 105 165 135 225 105 255 45 210 60 Polygon -7500403 true true 135 90 120 45 150 15 180 45 165 90 product true 0 Circle -13345367 true false 65 65 170 square false 0 Rectangle -7500403 true true 30 30 270 270 square 2 false 0 Rectangle -7500403 true true 30 30 270 270 Rectangle -16777216 true false 60 60 240 240 star false 0 Polygon -7500403 true true 151 1 185 108 298 108 207 175 242 282 151 216 59 282 94 175 3 108 116 108 substrate true 0 Circle -2674135 true false 70 70 160 target false 0 Circle -7500403 true true 0 0 300 Circle -16777216 true false 30 30 240 Circle -7500403 true true 60 60 180 Circle -16777216 true false 90 90 120 Circle -7500403 true true 120 120 60 tree false 0 Circle -7500403 true true 118 3 94 Rectangle -6459832 true false 120 195 180 300 Circle -7500403 true true 65 21 108 Circle -7500403 true true 116 41 127 Circle -7500403 true true 45 90 120 Circle -7500403 true true 104 74 152 triangle false 0 Polygon -7500403 true true 150 30 15 255 285 255 triangle 2 false 0 Polygon -7500403 true true 150 30 15 255 285 255 Polygon -16777216 true false 151 99 225 223 75 224 truck false 0 Rectangle -7500403 true true 4 45 195 187 Polygon -7500403 true true 296 193 296 150 259 134 244 104 208 104 207 194 Rectangle -1 true false 195 60 195 105 Polygon -16777216 true false 238 112 252 141 219 141 218 112 Circle -16777216 true false 234 174 42 Rectangle -7500403 true true 181 185 214 194 Circle -16777216 true false 144 174 42 Circle -16777216 true false 24 174 42 Circle -7500403 false true 24 174 42 Circle -7500403 false true 144 174 42 Circle -7500403 false true 234 174 42 turtle true 0 Polygon -10899396 true false 215 204 240 233 246 254 228 266 215 252 193 210 Polygon -10899396 true false 195 90 225 75 245 75 260 89 269 108 261 124 240 105 225 105 210 105 Polygon -10899396 true false 105 90 75 75 55 75 40 89 31 108 39 124 60 105 75 105 90 105 Polygon -10899396 true false 132 85 134 64 107 51 108 17 150 2 192 18 192 52 169 65 172 87 Polygon -10899396 true false 85 204 60 233 54 254 72 266 85 252 107 210 Polygon -7500403 true true 119 75 179 75 209 101 224 135 220 225 175 261 128 261 81 224 74 135 88 99 wheel false 0 Circle -7500403 true true 3 3 294 Circle -16777216 true false 30 30 240 Line -7500403 true 150 285 150 15 Line -7500403 true 15 150 285 150 Circle -7500403 true true 120 120 60 Line -7500403 true 216 40 79 269 Line -7500403 true 40 84 269 221 Line -7500403 true 40 216 269 79 Line -7500403 true 84 40 221 269 x false 0 Polygon -7500403 true true 270 75 225 30 30 225 75 270 Polygon -7500403 true true 30 75 75 30 270 225 225 270 @#$#@#$#@ NetLogo 4.0beta3 @#$#@#$#@ @#$#@#$#@ 0.1 org.nlogo.aggregate.gui.AggregateDrawing 33 org.nlogo.aggregate.gui.StockFigure "attributes" "attributes" 1 "FillColor" "Color" 225 225 182 131 184 60 40 org.nlogo.aggregate.gui.WrappedStock "Substrate2" "1" 1 org.nlogo.aggregate.gui.StockFigure "attributes" "attributes" 1 "FillColor" "Color" 225 225 182 111 379 60 40 org.nlogo.aggregate.gui.WrappedStock "Enzyme2" ".2" 1 org.nlogo.aggregate.gui.StockFigure "attributes" "attributes" 1 "FillColor" "Color" 225 225 182 462 185 60 40 org.nlogo.aggregate.gui.WrappedStock "ES" "0" 1 org.nlogo.aggregate.gui.StockFigure "attributes" "attributes" 1 "FillColor" "Color" 225 225 182 786 185 60 40 org.nlogo.aggregate.gui.WrappedStock "Product2" "0" 1 org.nlogo.aggregate.gui.RateConnection 3 534 204 654 204 774 204 NULL NULL 0 0 0 org.jhotdraw.standard.ChopBoxConnector REF 5 org.jhotdraw.standard.ChopBoxConnector REF 7 org.nlogo.aggregate.gui.WrappedRate "kf2 * ES" "product_form" REF 6 REF 8 0 org.nlogo.aggregate.gui.ConverterFigure "attributes" "attributes" 1 "FillColor" "Color" 130 188 183 736 373 50 50 org.nlogo.aggregate.gui.WrappedConverter "forward_rate_2" "kf2" org.nlogo.aggregate.gui.BindingConnection 2 752 381 654 204 NULL NULL 0 0 0 org.jhotdraw.contrib.ChopDiamondConnector REF 13 org.nlogo.aggregate.gui.ChopRateConnector REF 9 org.nlogo.aggregate.gui.BindingConnection 2 534 204 654 204 NULL NULL 0 0 0 org.jhotdraw.standard.ChopBoxConnector REF 5 org.nlogo.aggregate.gui.ChopRateConnector REF 9 org.nlogo.aggregate.gui.ConverterFigure "attributes" "attributes" 1 "FillColor" "Color" 130 188 183 22 271 50 50 org.nlogo.aggregate.gui.WrappedConverter "forward_rate_1" "kf1" org.nlogo.aggregate.gui.ConverterFigure "attributes" "attributes" 1 "FillColor" "Color" 130 188 183 427 258 50 50 org.nlogo.aggregate.gui.WrappedConverter "reverse_rate_1" "kr1" org.nlogo.aggregate.gui.ReservoirFigure "attributes" "attributes" 1 "FillColor" "Color" 192 192 192 127 165 30 30 org.nlogo.aggregate.gui.ReservoirFigure "attributes" "attributes" 1 "FillColor" "Color" 192 192 192 142 262 30 30 org.nlogo.aggregate.gui.ReservoirFigure "attributes" "attributes" 1 "FillColor" "Color" 192 192 192 10 193 30 30 org.nlogo.aggregate.gui.ReservoirFigure "attributes" "attributes" 1 "FillColor" "Color" 192 192 192 467 401 30 30 org.nlogo.aggregate.gui.RateConnection 3 203 204 326 204 450 204 NULL NULL 0 0 0 org.jhotdraw.standard.ChopBoxConnector REF 1 org.jhotdraw.standard.ChopBoxConnector REF 5 org.nlogo.aggregate.gui.WrappedRate "kf1 * Substrate2 * Enzyme2" "substrate_rxn" REF 2 REF 6 0 org.nlogo.aggregate.gui.StockFigure "attributes" "attributes" 1 "FillColor" "Color" 225 225 182 504 380 60 40 org.nlogo.aggregate.gui.WrappedStock "ghost_ES" "0" 1 org.nlogo.aggregate.gui.RateConnection 3 183 399 337 399 492 399 NULL NULL 0 0 0 org.jhotdraw.standard.ChopBoxConnector REF 3 org.jhotdraw.standard.ChopBoxConnector REF 33 org.nlogo.aggregate.gui.WrappedRate "kf1 * Substrate2 * Enzyme2" "enzyme_rxn" REF 4 REF 34 0 org.nlogo.aggregate.gui.BindingConnection 2 203 204 326 204 NULL NULL 0 0 0 org.jhotdraw.standard.ChopBoxConnector REF 1 org.nlogo.aggregate.gui.ChopRateConnector REF 29 org.nlogo.aggregate.gui.BindingConnection 2 65 289 326 204 NULL NULL 0 0 0 org.jhotdraw.contrib.ChopDiamondConnector REF 21 org.nlogo.aggregate.gui.ChopRateConnector REF 29 org.nlogo.aggregate.gui.BindingConnection 2 171 367 326 204 NULL NULL 0 0 0 org.jhotdraw.standard.ChopBoxConnector REF 3 org.nlogo.aggregate.gui.ChopRateConnector REF 29 org.nlogo.aggregate.gui.RateConnection 3 450 204 326 203 203 203 NULL NULL 0 0 0 org.jhotdraw.standard.ChopBoxConnector REF 5 org.jhotdraw.standard.ChopBoxConnector REF 1 org.nlogo.aggregate.gui.WrappedRate "kr1 * ES" "substrate_return" REF 6 REF 2 0 org.nlogo.aggregate.gui.BindingConnection 2 450 204 326 203 NULL NULL 0 0 0 org.jhotdraw.standard.ChopBoxConnector REF 5 org.nlogo.aggregate.gui.ChopRateConnector REF 48 org.nlogo.aggregate.gui.BindingConnection 2 436 273 326 203 NULL NULL 0 0 0 org.jhotdraw.contrib.ChopDiamondConnector REF 23 org.nlogo.aggregate.gui.ChopRateConnector REF 48 org.nlogo.aggregate.gui.RateConnection 3 492 399 337 399 183 399 NULL NULL 0 0 0 org.jhotdraw.standard.ChopBoxConnector REF 33 org.jhotdraw.standard.ChopBoxConnector REF 3 org.nlogo.aggregate.gui.WrappedRate "kf2 * ghost_ES" "ghost_product" REF 34 REF 4 0 org.nlogo.aggregate.gui.ReservoirFigure "attributes" "attributes" 1 "FillColor" "Color" 192 192 192 785 387 30 30 org.nlogo.aggregate.gui.BindingConnection 2 492 399 337 399 NULL NULL 0 0 0 org.jhotdraw.standard.ChopBoxConnector REF 33 org.nlogo.aggregate.gui.ChopRateConnector REF 58 org.nlogo.aggregate.gui.BindingConnection 2 736 398 337 399 NULL NULL 0 0 0 org.jhotdraw.contrib.ChopDiamondConnector REF 13 org.nlogo.aggregate.gui.ChopRateConnector REF 58 org.nlogo.aggregate.gui.BindingConnection 2 65 302 337 399 NULL NULL 0 0 0 org.jhotdraw.contrib.ChopDiamondConnector REF 21 org.nlogo.aggregate.gui.ChopRateConnector REF 35 org.nlogo.aggregate.gui.BindingConnection 2 183 399 337 399 NULL NULL 0 0 0 org.jhotdraw.standard.ChopBoxConnector REF 3 org.nlogo.aggregate.gui.ChopRateConnector REF 35 org.nlogo.aggregate.gui.BindingConnection 2 189 236 337 399 NULL NULL 0 0 0 org.jhotdraw.standard.ChopBoxConnector REF 1 org.nlogo.aggregate.gui.ChopRateConnector REF 35 org.nlogo.aggregate.gui.RateConnection 3 492 399 337 398 183 398 NULL NULL 0 0 0 org.jhotdraw.standard.ChopBoxConnector REF 33 org.jhotdraw.standard.ChopBoxConnector REF 3 org.nlogo.aggregate.gui.WrappedRate "kr1 * ghost_ES" "enzyme_return" REF 34 REF 4 0 org.nlogo.aggregate.gui.BindingConnection 2 439 295 337 398 NULL NULL 0 0 0 org.jhotdraw.contrib.ChopDiamondConnector REF 23 org.nlogo.aggregate.gui.ChopRateConnector REF 78 org.nlogo.aggregate.gui.BindingConnection 2 492 399 337 398 NULL NULL 0 0 0 org.jhotdraw.standard.ChopBoxConnector REF 33 org.nlogo.aggregate.gui.ChopRateConnector REF 78 @#$#@#$#@ @#$#@#$#@ @#$#@#$#@ default 0.0 -0.2 0 0.0 1.0 0.0 1 1.0 0.0 0.2 0 0.0 1.0 link direction true 0 Line -7500403 true 150 150 90 180 Line -7500403 true 150 150 210 180 @#$#@#$#@