########## NAME
ode_fat
########## METADATA
time_unit = m
########## MACROS
########## STATES
d/dt(TAGfood) = -vfatUptake                                     // umol/min (no volume, just amount)
d/dt(TAGp) = vfatUptake/Vplasma - vLPL                          // umol/L/min
d/dt(FFAp)=  vLPL*3 - vnetDiffusion                             // umol/L/min                                      
d/dt(FFAt)= vnetDiffusion*(Vplasma/Vtissue) - vFatUtalization   // umol/L/min
                                    
TAGfood(0) = 0 // umol
TAGp(0) = 0    // umol/L
FFAp(0) = 0    // umol/L
FFAt(0) = 0    // umol/L

########## PARAMETERS
kf = 0.015    // 1/min
vmax = 17     // umol/L/min
km = 100      // umol/L
kd = 0.08     // 1/min diffusion rate constant 
ku = 1        // 1/min
Vtissue = 1.2 // L
Vplasma = 3   // L

########## VARIABLES
vnetDiffusion = kd*FFAp - kd*FFAt
vLPL = TAGp*vmax/(TAGp+km)
vFatUtalization = FFAt*ku
vfatUptake = TAGfood*kf

########## FUNCTIONS
########## EVENTS
foodevent = food > 0, TAGfood, food+TAGfood  // if food is given as input, TAGfood is set to food

########## OUTPUTS
########## INPUTS
food = food_in @ 0 // @ 0 means that food has the value 0 if food_in is not given as input

########## FEATURES
TAG in food = TAGfood   [umol]
TAG in plasma = TAGp    [umol/L]
FFA in tissue = FFAt    [umol/L]
FFA in plasma = FFAp    [umol/L]

LPL reaction rate = vLPL                [umol/L/min]
Fat uptake rate = vfatUptake            [umol/min]
Fat utilization rate = vFatUtalization  [umol/L/min]
Net diffusion rate = vnetDiffusion      [umol/L/min]