Final answer:
Cytosolic enzymes function in a watery environment and are commonly involved in glycolysis, while mitochondrial enzymes are linked with the TCA cycle and oxidative phosphorylation, often bound to the inner mitochondrial membrane. Ubiquinone acts as a mobile electron transporter, while cytochrome c transfers electrons within the electron transport chain and triggers apoptosis when in the cytosol.
Step-by-step explanation:
The enzymes present in the cytosol and those found in the mitochondria have distinct roles and properties that align with their respective subcellular localizations. Cytosolic enzymes operate in an aqueous environment and often participate in pathways such as glycolysis, whereas mitochondrial enzymes are typically involved in the tricarboxylic acid (TCA) cycle, fatty acid oxidation, and oxidative phosphorylation, all of which occur within the mitochondria's specialized compartments. One key difference is the compartmentalization; mitochondrial enzymes, such as those in the electron transport chain, are bound to the inner mitochondrial membrane and work within the confines of the mitochondrial matrix or the intermembrane space.
The roles of ubiquinone and cytochrome c within the electron transport chain are particularly crucial. Ubiquinone acts as a mobile electron transporter within the lipid bilayer of the inner mitochondrial membrane, facilitating the transfer of electrons between different complexes. Cytochrome c, in contrast, is a peripheral membrane protein that can transfer electrons between Complex III and Complex IV in the chain but also has a role in apoptosis when released into the cytosol.
Moreover, cytochrome c's release from the mitochondria into the cytosol triggers the formation of a complex with adaptor proteins, which then activates procaspase to caspase, initiating the programmed cell death pathway. This function is distinct from its role in the electron transport chain.