Energy - Catabolic and Anabolic Pathways Energy is the ability to do work – The ability to do that work depends on catabolic process that harvest the chemical potential energy found in organic molecules. 2 basic strategies for harvesting energy – Autotrophy – Heterotrophy

Autotrophs Are organisms that produce energy from inorganic compounds and fix (PLACE) it into organic compounds for later use. – Photoautotrophs (plants, algae, some protists and bacteria) Convert the sun’s energy into sugar through photosynthesis – Chemoautotrophs Some bacteria use inorganic compounds to fix energy – Methanogens use the energy found in methane molecules

Heterotrophs Are organisms that consume organic compounds created by autotrophs to convert into the energy containing compound ATP – Although there are different strategies (herbivore, carnivore, & omnivore) ALL energy consumed originally came from the sun.

Production of ATP – ATP is produced in the mitochondria yielding 32 to 38ATP per molecule of glucose from existing ADP & inorganic phosphate (Pi) in the body – The chemical energy stored in the ATP can be later used by the body to power the reactions needed for survival » Growth, repair, energy production, reproduction, …

ATP = Energy ATP is the primary molecule used in the catabolic pathway to produce energy to power metabolic processes – ATP  ADP + Pi + energy