Describe these components compounds . ADP and ATP . NAD+ and NADH . NADP+ and NADPH
Describe these components compounds . ADP and ATP . NAD+ and NADH . NADP+ and NADPH
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ADP and ATP
Adenosine Diphosphate (ADP):
ADP consists of adenine (a nitrogenous base), ribose (a five-carbon sugar), and two phosphate groups. It is a low-energy molecule that acts as a precursor in energy metabolism. ADP is converted into ATP through the addition of a third phosphate group during cellular processes such as oxidative phosphorylation, substrate-level phosphorylation, or photophosphorylation.
Adenosine Triphosphate (ATP):
ATP is a high-energy molecule composed of adenine, ribose, and three phosphate groups. It serves as the primary energy currency of the cell, driving biochemical processes like muscle contraction, active transport, and chemical synthesis. The energy is released when ATP is hydrolyzed to ADP and inorganic phosphate (Pi), or to AMP (adenosine monophosphate) and pyrophosphate (PPi).
NAD⁺ and NADH
Nicotinamide Adenine Dinucleotide (NAD⁺):
NAD⁺ is an electron carrier molecule composed of two nucleotides: one containing an adenine base and the other a nicotinamide group. In its oxidized form (NAD⁺), it functions as a coenzyme in redox reactions, accepting electrons during catabolic processes like glycolysis, the citric acid cycle, and beta-oxidation.
NADH:
NADH is the reduced form of NAD⁺, carrying high-energy electrons and a proton (H⁺). It plays a key role in cellular respiration by donating these electrons to the electron transport chain, where they are used to generate ATP through oxidative phosphorylation.
NADP⁺ and NADPH
Nicotinamide Adenine Dinucleotide Phosphate (NADP⁺):
NADP⁺ is structurally similar to NAD⁺, but it contains an additional phosphate group on the ribose attached to the adenine nucleotide. This molecule is predominantly involved in anabolic reactions, where it acts as an electron acceptor.
NADPH:
NADPH is the reduced form of NADP⁺ and functions as a reducing agent in biosynthetic processes. It is essential for pathways such as fatty acid synthesis, cholesterol synthesis, and the Calvin cycle in photosynthesis. NADPH also provides electrons for detoxification reactions and the regeneration of antioxidants, such as glutathione.
