Factors that influence proteins and enzymes Flashcards
(24 cards)
What is the optimal temperature for enzyme function?
The optimal temperature is the temperature at which an enzyme performs its maximum function due to higher kinetic energy in the cell, leading to more frequent reaction-inducing collisions.
What happens to proteins when the temperature is too hot?
When the temperature is too hot, proteins will denature, losing their functional shape.
What happens to proteins when the temperature is too cold?
When the temperature is too cold, proteins experience little to no activity, as there is less kinetic energy. However, this can be reversed by applying heat.
What is the optimal pH for enzyme function?
The optimal pH is the pH level that causes the maximum amount of enzyme function to occur.
What happens to proteins when exposed to pH levels outside their optimal range?
Proteins will denature when exposed to pH levels outside of their optimal range.
How does substrate concentration affect enzyme activity?
At lower substrate concentrations, the reaction rate is slower. At higher substrate concentrations, the reaction rate increases, but only up to the saturation point.
What happens when substrate concentration reaches saturation?
Once the substrate concentration reaches saturation, the reaction rate will no longer increase, as all enzyme active sites are occupied.
What is potential energy?
Potential energy is stored energy in an object due to its position, properties, and forces acting on it.
What is kinetic energy?
Kinetic energy is the form of energy that an object possesses due to its motion.
What is Gibbs free energy?
Gibbs free energy represents the amount of energy available to do work in a chemical reaction. It is calculated as: [energy of reactants and products] - [energy lost] = Delta G (change in Gibbs free energy).
What is an exergonic reaction?
An exergonic reaction is spontaneous and has a negative ΔG. In this reaction, the energy of the reactants is greater than the energy of the products, and energy is released.
What is an endergonic reaction?
An endergonic reaction is non-spontaneous and has a positive ΔG. In this reaction, the energy of the reactants is less than the energy of the products, and energy is absorbed.
What is an example of an endergonic reaction?
A hydrolysis reaction is an example of an endergonic reaction, where water is split into a proton and hydroxyl group, breaking polymers into subunits.
What is the free energy difference when breaking down ATP?
The free energy difference when breaking down ATP is approximately -7.3 kcal/mol.
What are enzymes?
Enzymes are proteins that lower the activation energy needed to pass the transition state in a chemical reaction, allowing substrates to convert to products at a faster rate.
What is activation energy?
Activation energy is the amount of energy required to overcome the repulsive forces of reactants to form products, specifically to reach the transition state.
What is the transition state in a chemical reaction?
The transition state is the brief period in a chemical reaction where old bonds are breaking and new bonds are forming, and activation energy is needed.
How do enzymes work in a reaction?
Enzymes make chemical reactions more likely to proceed by stabilizing the transition state, reducing the activation energy, and increasing the rate of reaction.
What is the active site of an enzyme?
The active site is the region of the enzyme’s structure where the substrate binds and has a complementary shape to the substrate.
What are enzyme cofactors?
Enzyme cofactors are non-protein atoms or molecules required for enzyme catalytic activity, including inorganic metal ions and organic vitamins.
What is competitive inhibition?
Competitive inhibition occurs when an inhibitor molecule binds to the enzyme’s active site, preventing the substrate from binding, thus reducing the reaction rate.
What is non-competitive (allosteric) inhibition?
Non-competitive inhibition occurs when an inhibitor binds to an enzyme at a site other than the active site, changing the shape of the active site.
What is energetic coupling?
Energetic coupling is when cells use the excess energy from exergonic reactions to drive endergonic reactions. One reaction must be exergonic, the other endergonic, and the net ΔG must be negative.
What is an enzyme-substrate complex?
An enzyme-substrate complex is formed when enzymes bind substrates at a region of the enzyme.
