Calculate the number of repetitions of the β-oxidation pathway required to fully convert a 18-carbon activated fatty acid to acetyl-scoa molecules.

The answer is 5. An acetyl group (comprising two C atoms) is divided off the original fatty acyl-SCoA with each recurrence of the beta-oxidation spiral. So, the first repetition of the beta-oxidation produces one acetyl-SCoA molecule and a fatty acyl-SCoA molecule that is two carbon atoms smaller than the initial fatty acyl-SCoA. There will be five acetyl-SCoA molecules made by the fifth repetition. 

answer: semi-infinite solid initially at a uniform temperature of 400 ◦c is cooled at its surface by convection. the cooling fluid at a constant temperature of 200 ◦c has a convective coefficient (ha) of 250 w/m2.k. the physical properties of the solid: k = 20 w/m.k and α = 4 * 10-5  m2/s. using δx = 0.04 m and δt = 10 s. write the finite difference equations describing the transient heat transfer of the first five δx and the temperature profile after 30 s.