Presentation on theme: "Proteins that make reactions happen. Metabolism: the complete set of chemical reactions occurring in cells Anabolism: using energy to build macromolecules."— Presentation transcript:
Metabolism: the complete set of chemical reactions occurring in cells Anabolism: using energy to build macromolecules Catabolism: releasing energy by the enzymatic breakdown of macromolecules Energy Coupling: Energy released by the breakdown of a molecule is used to fuel the creation of another
Potential: stored energy ◦ Ex. Bowling ball held overhead The ability to cause change Kinetic: energy at work ◦ Ex. Bowling ball falling to the ground The occurrence of change
The formation and breaking of covalent bonds between atoms
Endothermic rxn: requires energy input Energy A + B + Energy -> AB Exothermic rxn: releases excess free energy as heat Energy AB -> A + B+ Energy
Adenosine Tri-phosphate Similar to a nucleotide but with 3 phosphate groups Used as energy currency for cells Energy is released when unstable third phosphate is released ATP is created during cellular respiration
By coupling an exothermic reaction (the release of a phosphate from ATP) with an endothermic reactions (the acceptance of the phosphate by an enzyme) cells can transfer energy between molecules to perform work
A protein Lowers the activation energy of a reaction (catalyst) Can be reused Typically uses ATP for the energy it requires
activity is reduced or halted The process by which enzymatic activity is reduced or halted by the presence of an inhibitory molecule that binds to the enzyme.
Competitive Inhibitory molecule binds directly to the active site, preventing substrate-enzyme complex Non-competitive Inhibitory molecule binds to another site (allosteric site) on enzyme, changing the 3-D shape of the enzyme so a substrate cannot bind to the active site
Non-competitive inhibition is an example of allosteric regulation Occurs when a protein’s function at one site is affected by the binding of a regulatory molecule to a separate site. Can result in stimulation or inhibition of enzyme activity.