Biology Chapter 8: Metabolism and Energy

Study Notes

Thousands of chemical reactions occur within living cells.
These reactions assemble small molecules into polymers, break down polymers into monomers, and transform energy.
Cells export chemical products and import raw materials.
Cellular respiration uses oxygen to break down fuels, such as sugar, releasing energy that powers cellular work.
Metabolism is a complex set of coupled chemical reactions that are highly organized, efficient, and responsive to changes.

The sum total of an organism's chemical reactions is called metabolism.
Metabolism is an emergent property of life that arises from interactions between molecules within the organized environment of a cell.
Metabolism is organized into metabolic pathways.
Each metabolic pathway begins with a specific molecule and proceeds through a series of steps, each catalyzed by a specific enzyme, to form a specific product.
Catabolic pathways release energy by breaking down complex molecules into simpler molecules.
Cellular respiration is a major pathway of catabolism in which sugars are fully broken down in the presence of oxygen to carbon dioxide and water, releasing energy.
The energy released by catabolic pathways becomes available to do work, such as biosynthesis and movement.