Module 1
Understanding Cellular Metabolism
Metabolism is the totality of an organism's chemical reactions. It manages the material and energy resources of the cell through two complementary metabolic pathways: Catabolism and Anabolism.
Catabolism (Breakdown)
Exergonic ($\Delta G < 0$)- Definition: Pathways that break down complex molecules into simpler compounds.
- Energy Dynamic: Releases energy stored in chemical bonds to produce ATP.
- Key Examples: Cellular Respiration ($C_6H_{12}O_6 + 6O_2 \rightarrow 6CO_2 + 6H_2O$), Digestion of Macromolecules.
Anabolism (Synthesis)
Endergonic ($\Delta G > 0$)- Definition: Pathways that consume energy to build complicated molecules from simpler ones.
- Energy Dynamic: Requires energy input (utilizes ATP produced by catabolism).
- Key Examples: Photosynthesis ($6CO_2 + 6H_2O \rightarrow C_6H_{12}O_6 + 6O_2$), Protein Synthesis, Glycogenesis.
The ATP Energy Coupling Cycle
ATP (Adenosine Triphosphate) acts as the cellular energy currency linking catabolic (exergonic) reactions to anabolic (endergonic) reactions.
Catabolic Reactions
Exergonic, energy-releasing processes
ATP
Cellular Energy
High Energy
Anabolic Reactions
Endergonic, energy-consuming processes