Energy-rich compounds

• Energy-rich compounds are essential for cellular metabolism, acting as molecular energy stores and carriers.

• These compounds release significant energy upon breaking high-energy bonds, driving various biological processes.

Key Energy-Rich Compounds

Adenosine Triphosphate (ATP)

• Structure: Adenine base, ribose sugar, and three phosphate groups.

• Function: Primary cellular energy currency, providing energy for muscle contraction, active transport, and biosynthesis.

• Significance: Central to metabolism and cellular homeostasis.

Guanosine Triphosphate (GTP)

• Structure: Similar to ATP, with guanine as the nitrogenous base.

• Function: Powers protein synthesis and signal transduction.

• Significance: Essential for cellular regulation and communication.

Nicotinamide Adenine Dinucleotide (NADH) & Flavin Adenine Dinucleotide (FADH₂)

• Structure: NADH is the reduced form of NAD⁺; FADH₂ is the reduced form of FAD.

• Function: Electron carriers in cellular respiration, donating electrons to the electron transport chain (ETC) for ATP production.

• Significance: Crucial for oxidative phosphorylation and energy generation.

Phosphocreatine

• Structure: High-energy phosphate compound found in muscle cells.

• Function: Rapidly regenerates ATP from ADP during high-energy demand.

• Significance: Provides immediate energy for intense physical activity.

Major Sources of Energy-Rich Compounds

1. Glycolysis: Converts glucose into pyruvate, yielding ATP and NADH in the cytoplasm.

2. Citric Acid Cycle (Krebs Cycle): Processes acetyl-CoA to generate ATP, NADH, and FADH₂ in mitochondria.

3. Oxidative Phosphorylation: Uses NADH and FADH₂ in the electron transport chain to produce ATP.

4. Photosynthesis (Plants, Algae, Bacteria): Converts light energy into chemical energy (ATP, NADPH) for glucose synthesis.

5. Beta-Oxidation of Fatty Acids: Breaks down fats into acetyl-CoA, producing ATP, NADH, and FADH₂.

6. Amino Acid Catabolism: Converts amino acids into metabolic intermediates for ATP generation, especially during fasting or exercise.

These energy-rich compounds and their metabolic pathways are vital for sustaining life and cellular functions.