Metabolism
the totality of an organism’s chemical reactions; transforms matter and energy
Metabolic Pathways
a series of chemical reactions occurring within a cell that are essential for its survival.
Catabolic pathways
release energy by breaking down complex molecules into simpler compounds through hydrolysis, Ex: Cellular respiration, the breakdown of glucose in the presence of oxygen
Anabolic pathways
consume energy to build complex molecules from simpler ones through dehydration reaction, Ex: Synthesis of protein from amino acids
What is kinetic energy?
energy doing work, generally energy in motion
What is potential energy?
stored energy
Explain why ATP represents usable potential energy for a cell.
Bonds between the PO4 groups of ATP can be broken by hydrolysis releasing energy; The energy released can be used to drive endergonic reactions
What are the two laws of thermodynamics?
- The principle of conservation of energy: the energy of the universe is constant, Energy can be transferred and transformed, but it cannot be created or destroyed. Energy is often lost as heat.
- Every energy transfer or transformation increases the entropy (disorder) and heat of the universe
How do endergonic and exergonic reactions relate to catabolic and anabolic reactions?
Catabolic reactions release energy therefore they are exergonic. Anabolic reactions absorb and store free energy therefore they are endergonic.
Why is the cycle of ATP breakdown and regeneration important to cells?
Energy released by breakdown reaction in the cell is used to phosphorylate ADP regenerating ATP. Regeneration is important in cells because a working muscle recycles a whole pool of ATP in less than a minute.
What are enzymes?
catalytic proteins
How do enzymes function?
Speeds up a reaction without being consumed by the reaction
