Enzymes Flashcards
What are enzymes?
Types of proteins that are biological catalysts that speed up the rate of a reaction and are not used up in the reaction. Each enzyme is specific in its action.
What are enzymes made up of?
Most are made out of proteins, which are long chains of amino acids, and are held by hydrogen bonds to keep their 3D shape.
What do enzymes do?
They catalyse chemical reactions to make the reaction easier to take place, and are not used up in the reaction.
They are fast acting as they have a high turnover number number, which means they can convert many molecules of substrates per unit time.
What are the three parts of an enzyme reaction?
Substrate
Active site
Enzyme
What is a catabolic enzyme reaction?
🐱 🚗☄
Breaking a larger molecule into smaller parts. H2O is used in the reaction
What is an anabolic enzyme reaction?
Joining 2 or more substrate molecules together into a larger more complex one.
H2O is released in the process
How do enzymes help with the reaction?
They reduce the stability of bonds in reactants to speed up the reaction rate as enzymes reduce the input of energy required by lowering the activation energy needed for a reaction to take place, giving an alternative pathway.
Allow the reaction to take place at lower temps found in cells of organisms.
What is the activation energy?
The energy needed to start a chemical reaction
Explain the lock and key enzyme action process
🔐
The enzyme and substrate attach to each other like a lock and keys, as substrate fits into a specific active site of the enzymes to form the enzyme-substrate complex.
The products have a different shape after the reaction has occurred and so longer fits into the active site anymore and so are repelled.
Explain the induced fit enzyme action process.
Active site may not correspond to the shape of the substrate and so it is able to modify itself around the substrate as it is flexible.
As a result of these stresses on the substrate, the activation energy required to kick-start the reaction is dramatically lowered and new products are formed faster, and then are repelled.
How does the induced fit affect the reactant?
As a result of these stresses on the substrate, the activation energy required to kick-start the reaction is dramatically lowered and new products are formed faster.
What are four factors that affect the function of enzymes?
Temperature
pH levels
Concentration of substrate
Concentration of enzymes
How does temperature affect the function of enzymes?
Enzymes have a narrow temperature range and an optimal range where they operate the best at.
Increasing the temperature gives the molecules greater kinetic energy, thus increasing the rate of collision.
What if the temperature is increased to high?
If the temperature is increased, relative activity is increased, but if it is too high beyond its optimum, it can change the shape of the enzyme (denaturation), because of this the substrate will not be able to fit in, and so the enzyme will not be able to function anymore.
How does the high temperature cause denaturation?
As high temps break hydrogen bonds that hold enzymes together
What happens if the temperature is too cold?
It will cause the enzyme to stop operating as there is a reduction in particle movement and this will decrease the rate of reaction.
How does pH affect the function of enzymes?
Enzymes are sensitive to pH.
All enzymes have an optimum pH where their activity rate is the fastest, but if the pH is outside this range activity is reduced, and if it is really extreme (further away from its optimum) results in denaturation.
Different Enzymes function at different pH, Most have their optimum pH at 7
How does enzyme concentration affect the function of enzymes?
As if there is more enzymes added there will be more frequent collisions with substrates, making the reaction rate faster.
If there were less enzymes added then there be less frequent collisions with substrates, slowing down the reaction rate.
