Chapter 15.10, Problem 3QQ

Interpretation Introduction

Interpretation:

To determine the number of B vitamins needed in the degradation pathways for the carbon skeletons of the 20 standard amino acids.

Concept introduction:

Amino acids are the main building blocks of proteins. Amino acids that participate in peptide bond synthesis in proteins are known as standard amino acids. There are 20 standard amino acids. Each amino acid has a different carbon skeleton and has a different degradation pathway for its carbon skeleton. However, different degradation pathway does not result in the production of 20 different products.

The degradation pathways for different amino acids merge in between and result in the formation of only 7 products. The 7 products are $\text{α-ketoglutarate}$, $\text{succinyl CoA}$, fumarate, oxaloacetate, pyruvate, $\text{acetyl CoA}$ and $\text{acetoacetyl CoA}$. Four products $\text{α-ketoglutarate}$, $\text{succinyl CoA}$, fumarate, oxaloacetate are citric acid cycle intermediates.

Coenzymes are non-protein organic compounds that are used along with the enzymes and help to carry forward the reaction. Coenzymes cannot perform on their own alone.

The coenzymes containing B-vitamin serve as temporary carriers of atoms or functional groups in the redox and group transfer reactions associated with the metabolism of ingested food in order to obtain energy from the food.