Fig. 2

An overview of major metabolic pathways. Cellular metabolism is a complex network of interconnected pathways that respond to internal and external signals to meet the cell's needs. These pathways function in a coordinated manner to produce essential components for cellular function and are subject to regulation by various signaling mechanisms. Here is an overview of the major metabolic pathways and their roles. Glycolysis is the process by which glucose is converted into pyruvate. Subsequently, pyruvate can further transform into lactate or be integrated into the tricarboxylic acid (TCA) cycle. Within the TCA cycle, pyruvate undergoes a series of reactions that produce NADH and FADH2, which the oxidative phosphorylation (OXPHOS) electron transport chain (ETC) system uses to generate ATP. Furthermore, glycolysis supplies intermediates for the pentose phosphate pathway (PPP), which produces ribose for nucleotides and amino acids. Lipid metabolism involves synthesizing fatty acids and lipid transportation, a process involving citrate derived from the TCA cycle. Moreover, it has been demonstrated that fatty acids can undergo oxidation, generating NADH and FADH2, which, in turn, promote ATP production through the OXPHOS. Amino acid metabolism also provides vital nutrients for the TCA cycle and plays a significant role in protein biosynthesis and adequate cellular activation. The intricate interconnection and regulation of these pathways by cellular signaling ensure metabolic activity aligns with the cell's requirements. This coordinated system enables cells to produce energy and essential molecules for various physiological processes efficiently