To enter into the respiratory pathway,protein molecules must be converted into:

Which of the following pairs is a combination of the highest and lowest energy molecules?

Choose the incorrect sentence$(s)$ regarding the amphibolic pathway.
$(1)$ Carbohydrates are generally used as substrates for respiration.
$(2)$ Fatty acids can first be degraded into acetyl $CoA$,which enters the respiratory pathway.
$(3)$ In the case of proteins,they are first broken down into amino acids,which are later converted into pyruvic acid and enter the respiratory pathway.
$(4)$ The respiratory pathway is involved in both anabolism and catabolism.
$(5)$ Glycerol would enter the pathway after being converted to $PGAL$.

The maximum amount of energy / $ATP$ is released during the oxidation of which of the following?

Respiratory pathway is believed to be a catabolic pathway. However,the nature of the $TCA$ cycle is amphibolic. Explain.

Maximum energy can be obtained from the oxidation of which respiratory substrate?