Biochemistry & Pharmacology: Open Access
Open Access

Biochemical Pathways in Biotechnology: Applications in Medicine and Agriculture

Sarah Yosef Department of Biochemistry, Hebrew University, Jerusalem^{* *}Correspondence: Sarah Yosef, Department of Biochemistry, Hebrew University, Jerusalem, Israel, Email:

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Description

Biochemical pathways are complex networks of chemical reactions that occur within living organisms orchestrating the conversion of molecules to sustain life. These pathways are need for cellular function growth and response to environmental changes forming the foundation of metabolism and physiology.

The basics of biochemical pathways

Biochemical pathways involve a series of enzymatically catalysed reactions where each step transforms a specific molecule called a substrate into a product. Enzymes which are specialized proteins lower the activation energy required for these reactions ensuring their efficiency and specificity. Pathways can be linear cyclic or branched reflecting the diversity of biological processes. These pathways are broadly categorized into two types:

Catabolic pathways: These break down complex molecules into simpler ones releasing energy stored in chemical bonds. For example, glycolysis the breakdown of glucose produces energy in the form of ATP.

Anabolic pathways: These synthesize complex molecules from simpler ones requiring energy input. The synthesis of proteins from amino acids is a prime example of an anabolic process.

Key biochemical pathways

Here are some of the most important biochemical pathways that support fundamental physiological functions:

Glycolysis: Glycolysis is a universal catabolic pathway that converts glucose into pyruvate yielding ATP and NADH. This process occurs in the cytoplasm and does not require oxygen making it an important source of energy in anaerobic conditions. The products of glycolysis serve as precursors for other pathways including the citric acid cycle and fermentation.

Citric acid cycle: The citric acid cycle is a central hub of metabolism where Acetyl-CoA is oxidized to produce ATP, NADH and FADH2. This pathway occurs in the mitochondria and integrates catabolic and anabolic processes. The cycle’s intermediates are also precursors for biosynthetic pathways such as amino acid and nucleotide synthesis.

Electron Transport Chain (ETC): The ETC is the final stage of cellular respiration occurring in the mitochondrial inner membrane. Electrons from NADH and FADH2 are transferred through a series of protein complexes creating a proton gradient that drives ATP synthesis via oxidative phosphorylation. This pathway is highly efficient producing the majority of ATP in aerobic organisms.

Photosynthesis: In plants algae and certain bacteria photosynthesis captures light energy to synthesize glucose from carbon dioxide and water. The process involves two main stages, the light-dependent reactions and the Calvin cycle. Photosynthesis not only sustains autotrophs but also provides oxygen and organic compounds need for life on Earth.

Pentose Phosphate Pathway (PPP): The PPP is a metabolic pathway parallel to glycolysis that generates NADPH and ribose-5-phosphate. NADPH is crucial for reductive biosynthesis and maintaining cellular redox balance while ribose-5-phosphate is a precursor for nucleotide synthesis.

Regulation of biochemical pathways

Biochemical pathways are tightly regulated to maintain homeostasis and adapt to changing environmental conditions.

Allosteric regulation: Enzymes can be activated or inhibited by molecules that bind to sites other than the active site. For instance, ATP inhibits phosphofructokinase in glycolysis preventing excess energy production.

Feedback inhibition: End products of a pathway can inhibit upstream enzymes preventing overproduction of molecules.

Post-translational modifications: Phosphorylation acetylation and other modifications alter enzyme activity enabling rapid responses to signals.

Gene expression: The synthesis of enzymes involved in pathways can be upregulated or downregulated providing long-term control.

Biochemical pathways and health

Dysregulation of biochemical pathways is associated with various diseases. For example,

Diabetes: Impaired glucose metabolism due to dysfunction in glycolysis and gluconeogenesis contributes to hyperglycemia.

Cancer: Abnormal activation of anabolic pathways supports uncontrolled cell proliferation while altered glycolysis (Warburg effect) provides energy for tumour growth.

Neurodegenerative diseases: Mitochondrial dysfunction and impaired ETC activity are linked to Alzheimer’s and Parkinson’s diseases.

Applications of biochemical pathways

Understanding biochemical pathways has led to numerous applications in medicine agriculture and biotechnology.

Drug development: Targeting specific enzymes in pathways has yielded treatments for diseases like hypertension (ACE inhibitors) and cancer (kinase inhibitors).

Metabolic engineering: Modifying pathways in microorganisms enables the production of biofuels pharmaceuticals and other valuable compounds.

Diagnostics: Biomarkers derived from pathway intermediates aid in the early detection of diseases.

Biochemical pathways are the blueprint of life governing the flow of energy and matter in living systems. Their study not only improves our understanding of biology but also drives advancements in health and technology. By continuing to unravel these complex networks scientists can develop innovative solutions to address global challenges and improve human well-being.