Cytochrome P450 (CYP) proteins are a large family of heme-thiolate enzymes that play crucial roles in various biological processes, including drug metabolism, xenobiotic degradation, and biosynthesis of hormones and structural compounds. These proteins are found in nearly all organisms, with a particularly high number in plants. CYP genes are highly diverse in amino acid sequence, yet their structural fold remains conserved. The CYP superfamily is divided into classes based on electron transfer mechanisms, with Class I requiring FAD-containing reductases, Class II using FAD/FMN-containing reductases, Class III being self-sufficient, and Class IV receiving electrons directly from NAD(P)H. CYP enzymes catalyze a wide range of reactions, including hydroxylation, oxidation, and rearrangement of substrates. They are involved in vital processes such as carbon assimilation, hormone biosynthesis, and the detoxification of harmful substances. In plants, CYP diversity is linked to chemical defense mechanisms. In eukaryotes, CYPs are often membrane-bound, with some localized in the endoplasmic reticulum or mitochondria. The electron transfer process varies depending on the subcellular localization. The CYP superfamily has a complex evolutionary history, involving gene duplication, amplification, and lateral gene transfer. Gene clusters are common in many organisms, with some containing up to 15 CYP genes. The CYP51 family is conserved across phyla, including plants, fungi, and animals, and is involved in sterol biosynthesis. CYP enzymes are essential for drug metabolism and pesticide tolerance, and their activity can be induced by exogenous chemicals. CYPs are critical for drug metabolism and xenobiotic detoxification, with significant economic and pharmacological impacts. Their catalytic mechanisms involve oxygen activation and electron transfer, with recent studies revealing the presence of two electrophilic oxidants in the reaction pathway. CYPs are also involved in various physiological functions, including steroid hormone biosynthesis and signaling molecule metabolism. The study of CYP enzymes has led to significant advances in understanding their structure, function, and evolution. Research continues to explore their roles in plant defense, drug metabolism, and the development of new therapeutic strategies. Despite extensive research, many aspects of CYP function, including their physiological roles and subcellular localization, remain areas of active investigation.Cytochrome P450 (CYP) proteins are a large family of heme-thiolate enzymes that play crucial roles in various biological processes, including drug metabolism, xenobiotic degradation, and biosynthesis of hormones and structural compounds. These proteins are found in nearly all organisms, with a particularly high number in plants. CYP genes are highly diverse in amino acid sequence, yet their structural fold remains conserved. The CYP superfamily is divided into classes based on electron transfer mechanisms, with Class I requiring FAD-containing reductases, Class II using FAD/FMN-containing reductases, Class III being self-sufficient, and Class IV receiving electrons directly from NAD(P)H. CYP enzymes catalyze a wide range of reactions, including hydroxylation, oxidation, and rearrangement of substrates. They are involved in vital processes such as carbon assimilation, hormone biosynthesis, and the detoxification of harmful substances. In plants, CYP diversity is linked to chemical defense mechanisms. In eukaryotes, CYPs are often membrane-bound, with some localized in the endoplasmic reticulum or mitochondria. The electron transfer process varies depending on the subcellular localization. The CYP superfamily has a complex evolutionary history, involving gene duplication, amplification, and lateral gene transfer. Gene clusters are common in many organisms, with some containing up to 15 CYP genes. The CYP51 family is conserved across phyla, including plants, fungi, and animals, and is involved in sterol biosynthesis. CYP enzymes are essential for drug metabolism and pesticide tolerance, and their activity can be induced by exogenous chemicals. CYPs are critical for drug metabolism and xenobiotic detoxification, with significant economic and pharmacological impacts. Their catalytic mechanisms involve oxygen activation and electron transfer, with recent studies revealing the presence of two electrophilic oxidants in the reaction pathway. CYPs are also involved in various physiological functions, including steroid hormone biosynthesis and signaling molecule metabolism. The study of CYP enzymes has led to significant advances in understanding their structure, function, and evolution. Research continues to explore their roles in plant defense, drug metabolism, and the development of new therapeutic strategies. Despite extensive research, many aspects of CYP function, including their physiological roles and subcellular localization, remain areas of active investigation.