Cellular Locations

Cytosol:

• Glycolysis
• Pentose Phosphate Pathway (HMP Shunt)
• Fatty Acid Synthesis
• Protein Synthesis (initial stages, free ribosomes)
• Gluconeogenesis (major parts)
• Heme Synthesis (parts)
• Urea Cycle (parts)
• Glycogen synthesis & breakdown

Mitochondria:

• Krebs Cycle (TCA Cycle)
• Electron Transport Chain & Oxidative Phosphorylation (inner membrane)
• Fatty Acid Beta-Oxidation (matrix)
• Pyruvate Dehydrogenase Complex (PDH) (matrix)
• Ketone Body Synthesis (liver)
• Urea Cycle (initial steps)
• Heme Synthesis (initial & final steps)
• Gluconeogenesis (pyruvate carboxylation)
• Steroid Hormone Synthesis (initial & some later steps)

Rough Endoplasmic Reticulum (RER):

• Synthesis of secretory, membrane, and lysosomal proteins
• N-linked glycosylation (initial)
• Protein folding

Smooth Endoplasmic Reticulum (SER):

• Lipid & steroid hormone synthesis
• Detoxification (e.g., cytochrome P450 in liver)
• Calcium storage
• Omega-oxidation of fatty acids

Golgi Apparatus:

• Protein modification (e.g., further glycosylation)
• Sorting and packaging of proteins into vesicles

Peroxisomes:

• Beta-oxidation of Very-Long-Chain Fatty Acids (VLCFAs)
• Plasmalogen synthesis
• Detoxification (e.g., catalase for H₂O₂)