Rutas Anabólicas y Ciclo de Krebs

Anabolic Pathways

• Anabolic pathways are biosynthetic pathways that build complex molecules from simpler ones.
• They generally require energy input, often in the form of ATP.
• Examples include protein synthesis, DNA replication, and the synthesis of carbohydrates and lipids.
• They are crucial for growth, repair, and maintenance of the organism.
• Anabolic pathways are often regulated to maintain homeostasis.

Citric Acid Cycle (Krebs Cycle)

• The Krebs cycle is a series of enzyme-catalyzed reactions that occur in the mitochondrial matrix.
• It is the central metabolic pathway for oxidizing acetyl-CoA derived from carbohydrates, fats, and proteins.
• The cycle generates reducing equivalents (NADH and FADH2), ATP, and intermediates for other metabolic pathways.
• It's a crucial part of cellular respiration, providing energy and building blocks.
• Key products include CO2, ATP, NADH, and FADH2.
• The cycle regenerates the starting molecule, oxaloacetate, allowing for continuous operation.
• The cycle starts and ends with the 4-carbon molecule oxaloacetate.

Oxidative Phosphorylation

• This is a metabolic pathway where energy from the oxidation of NADH and FADH2 is used to generate ATP.
• It occurs in the inner mitochondrial membrane.
• The process involves a series of redox reactions, generating a proton gradient across the inner mitochondrial membrane.
• Electron transport chains are a key part of this process.
• Oxidative phosphorylation accounts for most of the ATP synthesis in aerobic organisms.

Electron Transport Chain

• The electron transport chain (ETC) is a series of protein complexes embedded in the inner mitochondrial membrane.
• It uses the electrons carried by NADH and FADH2 to pump protons (H+) across the membrane, creating a proton gradient.
• This gradient drives ATP synthase, an enzyme that generates ATP from ADP and inorganic phosphate.
• The final electron acceptor in the chain is oxygen, forming water.
• The ETC is essential for efficient energy extraction from nutrients.
• The complexes in the ETC transfer electrons stepwise through different redox couples generating energy.
• The flow of electrons along the chain is exergonic, releasing energy that drives protons across the membrane.