Lecture 7 Flashcards
What is metabolism?
All of a cells chemical reactions
What is Anabolism? Where do they get energy from?
Reactions that require energy to organize the cell. They get ATP produced by catabolic reactions
What is Catabolism?
Reactions that release energy from breakdown of nutrients. ADP from anabolic reactions is recycled into catabolic reactions.
What does endergonic mean?
Reactions that are nonspontaneous and require energy, they have a positive G. This means G increases
What is G?
Gibbs free energy
What does exergonic mean?
Reactions that are spontaneous and release energy, they have negative G which means G decreases
Why does ATP store energy?
ATP has a third phosphate which makes the reactant more reactive or more spontaneous
How are exer- and endergonic reactions combined?
They are combined to drive endergonic reactions, resulting in the final reaction actually being exergonic
What are Enzymes and what do they do?
Enzymes are biological catalysts that give an alternate path for a reaction with a lower activation energy. They function in both exer- and endergonic reactions
How do enzymes work?
They bind and act on substrates at the catalytic site, the substrates they can bind too are very specific
What is the catalytic site? How do enzymes bind there?
The binding site of the enzyme that is geometrically and chemically compatible with a substrate. They bind noncovalently
What are the ways an enzyme can work?
- Bring the reactants closer together 2. Catalytic site contains a unique environment favorable for the reaction 3. Physically stress bonds to be broken 4. Covalently stabilize reaction intermediate (Rare) 5. Place substrates in correct orientation
What are competitive inhibitors?
Binds to the catalytic site which stops the substrate. Can be out competed by increasing the substrate concentration
What are noncompetitive inhibtitors?
Bind to enzyme at a different site then the catalytic site and inhibits the substrate, cannot add more substrate to overcome
