Lecture 5: Enzymes Flashcards
(18 cards)
What is metabolism?
Metabolism is all the chemical reactions in the body, including both building up (anabolism) and breaking down (catabolism) of substances.
What is the role of enzymes in metabolism?
Enzymes act as biological catalysts that speed up metabolic reactions by lowering the activation energy required.
Define exergonic reaction.
An exergonic reaction is a chemical reaction where the reactants have more energy than the products, releasing energy and occurring spontaneously.
Define endergonic reaction.
An endergonic reaction is a chemical reaction where the products have more energy than the reactants, requiring an input of energy to proceed.
What is ATP and why is it important?
ATP (adenosine triphosphate) is a molecule that stores and transfers energy within cells, often referred to as the energy currency of the cell.
What is Gibbs free energy?
Gibbs free energy is the energy available to do work in a system, and changes in Gibbs free energy (ΔG) determine whether a reaction is spontaneous.
What is the difference between competitive and non-competitive enzyme inhibitors?
Competitive inhibitors bind to the active site of an enzyme, blocking substrate binding, while non-competitive inhibitors bind elsewhere, changing the enzyme’s shape and function.
What is the role of cofactors and coenzymes in enzyme activity?
Cofactors and coenzymes are non-protein molecules that assist enzymes in catalyzing reactions, often by stabilizing enzyme-substrate complexes.
What is feedback inhibition in metabolic pathways?
Feedback inhibition is a regulatory mechanism where the end product of a metabolic pathway inhibits an enzyme involved in its synthesis, preventing overproduction.
How does temperature affect enzyme activity?
Enzymes have an optimal temperature range; too high or too low temperatures can denature the enzyme, reducing its activity.
What is the first law of thermodynamics?
The first law of thermodynamics states that energy can be transferred or transformed but cannot be created or destroyed.
What is the second law of thermodynamics?
The second law of thermodynamics states that energy transformations increase the entropy (disorder) of the universe.
What is the induced fit model of enzyme activity?
The induced fit model suggests that enzyme active sites change shape to fit the substrate more snugly, enhancing catalysis.
What is the significance of the active site in enzyme function?
The active site is the region on an enzyme where substrate molecules bind and undergo a chemical reaction.
What is phosphorylation?
Phosphorylation is the addition of a phosphate group to a molecule, often used to activate or deactivate enzymes and other proteins.
What is activation energy
Initial energy to break chemical bonds
Explain atp regeneration
Allosteric regulation
Protein function at one site is affected by the binding of regulatory binding of separate site
