Enzymes Flashcards
What are the functions of enzymes?
3 Break 1 Build:
1) Build up/ synthesise complex substances
2) Break down large food molecules into smaller molecules
3) Break down food substances in cells to release energy
4) Break down poisonous substances in cells
What is a catalyst?
A substance that can increase the rate of chemical reaction, without itself being chemically altered at the end of a reaction.
What are enzymes?
Enzymes are biological catalysts which speeds up chemical reactions without themselves being changed at the end of a reaction.
What is the difference between anabolic and catabolic?
Anabolic synthesizes substance.
Catabolic breaks down substance.
What is activation energy?
It is the minimum energy required to initiate a chemical reaction.
Why is activation energy needed in all chemical reaction?
It is needed to break chemical bonds [1] in order to trigger the reaction to occur [1].
How does activation energy affect the speed at which a chemical reaction occur?
The lower the activation energy, the faster chemical reactions can take place at a faster rate.
(refer to activation energy graph)
Why does chemical reaction take place at a faster rate at normal temperature?
At normal temperature, molecules move fast enough due to the heat energy, increasing its kinetic energy. Thus, the number of molecules moving fast enough to react increases, which results in the faster formation of products.
What are the characteristics of an enzyme?
1) Sensitive to temperature
2) sensitive to pH
3) Specific (substrate specificity)
4) Required in minute amounts
5) Catalyse reversible reactions
Why are enzymes inactive at low temperature?
As temperature is decreased the enzymes and substrate loses kinetic energy (move less quickly). This decreases effective collision and the formation of enzyme-substrate complexes. Therefore as the temperature is decreased, the enzyme activity and the rate of reaction decreases. Thus, inactive.
Why are enzymes denatured at high temperature?
the weak hydrogen bonds are broken down [1] due to vigorous vibrations of the atoms in the enzyme [1]. enzyme lose its specific shape and active site to carry out chemical reaction [1]. Thus, it is denatured.
Do you agree with the statement “Enzymes are denatured below optimum temperature?” Explain.
No. At low temperatures, the enzymes loses kinetic energy. As such, there is a decrease in effective collision. Thus, it is said to be inactive rather than denatured as it’s active site is not being changed/ disrupted.
The higher the rate of enzyme, the ________ the time taken for enzyme to digest the substrate.
lesser
Why do enzymes work best at their optimum temperature?
At optimum temperature, the kinetic energy in the substrate and enzyme molecules is ideal for the maximum number of collisions. [1] As such, there would be an increase in the formation of enzyme-substrate complexes. [1]Thus, the rate of enzyme action is the highest.
What is denaturation?
Denaturation is when an enzyme loses its active site, losing its function.
How does difference in pH affect enzymes?
Difference in pH changes the surface configuration of the enzyme. When it is at extreme, it may cause denaturation to occur causing the enzyme to lose it’s active site as enzymes are protein in nature.
Does extreme pH denature enzymes? Explain.
Yes. At extreme pH, it causes the enzymes to change their surface configuration, in turn losing it’s active site. As such, there will not be any enzyme-substrate formed as the enzyme is denatured.
Why does enzyme work on different substrates?
Enzymes are specific due to their surface configuration which is called the active site. Thus, only substrates that have shape complementary to that of the enzyme can fit and react with it.
Why are enzymes required in minute amount?
Enzymes are required in minute amount as they remain unchanged after a reaction. Thus, it can be reused.
What is a reversible reaction?
A reversible chemical reaction is a reaction which the products can change back to the original reactants under suitable conditions.
Is lock the substrate?
No, it is the enzyme.
What is a limiting factor?
A limiting factor is a factor that directly affects the rate of chemical reaction if the amount is changed.
