Energy Metabolism: Catabolic & Anabolic Reactions

[beocom6000yello]

Is it safe to assume that catabolic reactions are always exergonic and anabolic reactions are always endergonic?

Also, I had a question on energy metabolism. Since the mitochondria is where energy is stored, does that mean that metabolic (energy) pathways only occur in the mitochondria? Or is there some other place in the cell that it can be done? I had this question:
Metabolic pathways ________________.

are often organized as a multi-step sequence of reactions
None of these.
occur only in mitochondria
only link smaller molecules together to create polymers
always break down large molecules into smaller ones

Would it be only occur in mitochondria?


Thanks!

 

[Ygggdrasil]

Is it safe to assume that catabolic reactions are always exergonic and anabolic reactions are always endergonic?

No. Overall, catabolic pathways are exergonic and anabolic pathways are endergonic, but there can be endergonic steps in a catabolic pathway and exergonic steps in an anabolic pathway.

Also, I had a question on energy metabolism. Since the mitochondria is where energy is stored, does that mean that metabolic (energy) pathways only occur in the mitochondria? Or is there some other place in the cell that it can be done?

Energy is not stored in the mitochondria. Mitochondria is where many metabolic reactions occur, such as the Krebs cycle and the electron transport chain, which is responsible for much of the energy production in the cell, but the molecules that fuel these processes are usually stored elsewhere in the cell. While many important metabolic processes occur in the mitochondria, many metabolic processes occur outside of the mitochondria. For example, glycolysis occurs in the cytoplasm.