Proteins some amino acids (monomer of protein) will get broken down for energy via cellular respiration
Hope this helps!
Cartilage, bone and fat (see connective tissues section of article)
The reason why taq polymerase is used is because it is thermostable, meaning that it can remain intact and reactive after being exposed to the cycles of high temperatures that are used in PCR (an upwards of 94 degrees Celsius). If human DNA polymerase were used instead, it would immediately unfold and become inactive after the first round of high temperatures, effectively ceasing the PCR.