NADP metabolic process

Definition

Target type: biologicalprocess

The chemical reactions and pathways involving nicotinamide-adenine dinucleotide phosphate, a coenzyme involved in many redox and biosynthetic reactions; metabolism may be of either the oxidized form, NADP, or the reduced form, NADPH. [GOC:mah]

NADP metabolic process is a fundamental biological pathway that plays a crucial role in various cellular functions, particularly photosynthesis and energy metabolism. It involves the synthesis, reduction, and utilization of nicotinamide adenine dinucleotide phosphate (NADP), a critical coenzyme in redox reactions.

**1. NADP Synthesis:**
- NADP is synthesized from NAD+ (nicotinamide adenine dinucleotide) by the enzyme NAD kinase, which utilizes ATP to phosphorylate NAD+ at the 2'-hydroxyl group of the adenosine ribose.

**2. NADPH Production:**
- NADP is reduced to NADPH by enzymes called reductases, which utilize electrons from various sources, such as light in photosynthesis or metabolic reactions like the pentose phosphate pathway.
- During photosynthesis, the light-dependent reactions generate electrons from water molecules, which are used to reduce NADP+ to NADPH.

**3. NADPH Utilization:**
- NADPH is a crucial reducing agent that provides electrons for various anabolic processes, including:
- **Photosynthesis:** NADPH is essential for the Calvin cycle, where it reduces carbon dioxide to carbohydrates, the primary energy source for plants.
- **Fatty acid biosynthesis:** NADPH provides electrons for the reduction of acetyl-CoA to fatty acids, which are building blocks for cell membranes and other molecules.
- **Steroid biosynthesis:** NADPH is involved in the reduction of steroid precursors to cholesterol and other steroids.
- **Detoxification:** NADPH is utilized by enzymes like cytochrome P450 monooxygenases to reduce harmful toxins.

**4. NADPH Regeneration:**
- NADPH is regenerated through the oxidation of NADPH to NADP+ by various enzymes, such as those involved in the electron transport chain and other metabolic pathways.

**5. Regulation of NADP Metabolism:**
- The NADP metabolic process is tightly regulated to ensure adequate NADPH supply for anabolic processes. This regulation occurs at multiple levels, including:
- **Enzyme activity:** The activity of enzymes involved in NADP synthesis and utilization is regulated by various factors, such as substrate availability and allosteric effectors.
- **Gene expression:** The expression of genes encoding NADP metabolic enzymes is regulated by various stimuli, such as light, hormones, and nutrient availability.

In summary, the NADP metabolic process is a complex and vital pathway that plays a central role in energy production, biosynthesis, and detoxification. Its regulation ensures that cells have the appropriate supply of NADPH for anabolic processes and the proper balance of NADP and NADPH for redox reactions.'
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Proteins (5)

Compounds (53)