Quiz 2.A
1) What is an enzyme?
An enzyme is a biological catalyst
2) What is a substrate?
A substrate is the molecule that an enzyme acts on
3) What is an active site?
The active site is the part of the enzyme that the substrate fits into
4) What is a catalyst?
A catalyst is a chemical that speeds up the rate of a reaction without being used up in the reaction
5) What are the two factors that affect the performance of a normal enzyme? Draw the graphs that show the rate of reaction against these variables.
See the two graph in section 2.5
6) Explain how an enzyme works.
The substrate fits into the active site of the enzyme and attaches itself to it. The reaction then takes place and the products are formed (the reaction may be a joining or separating of substances).
There is a longer definition of how an enzyme works in section 2.4.
7) What is the optimal temperature for an enzyme in the human body?
37°C
8) What is the optimal pH for a normal enzyme in the body?
7
9) What is the optimal pH for pepsin?
Around 2
10) Why does the rate of reaction increase as the temperature rises to the optimal temperature?
The substrates and the enzyme have more heat energy and therefore more kinetic energy. This means that the likelihood of them colliding increases and so does the rate of reaction.
11) Why does the rate of reaction fall when the temperature goes above the optimal temperature?
The enzyme denatures
12) What does denaturing mean?
Denaturing is where the proteins that the enzyme are made up of start to break apart. This causes the shape of the enzyme to change (including the shape of the active site). As the shape of the active site has changed, the substrate can no longer fit into the active site, which means that the enzyme does not function correctly.
An enzyme is a biological catalyst
2) What is a substrate?
A substrate is the molecule that an enzyme acts on
3) What is an active site?
The active site is the part of the enzyme that the substrate fits into
4) What is a catalyst?
A catalyst is a chemical that speeds up the rate of a reaction without being used up in the reaction
5) What are the two factors that affect the performance of a normal enzyme? Draw the graphs that show the rate of reaction against these variables.
See the two graph in section 2.5
6) Explain how an enzyme works.
The substrate fits into the active site of the enzyme and attaches itself to it. The reaction then takes place and the products are formed (the reaction may be a joining or separating of substances).
There is a longer definition of how an enzyme works in section 2.4.
7) What is the optimal temperature for an enzyme in the human body?
37°C
8) What is the optimal pH for a normal enzyme in the body?
7
9) What is the optimal pH for pepsin?
Around 2
10) Why does the rate of reaction increase as the temperature rises to the optimal temperature?
The substrates and the enzyme have more heat energy and therefore more kinetic energy. This means that the likelihood of them colliding increases and so does the rate of reaction.
11) Why does the rate of reaction fall when the temperature goes above the optimal temperature?
The enzyme denatures
12) What does denaturing mean?
Denaturing is where the proteins that the enzyme are made up of start to break apart. This causes the shape of the enzyme to change (including the shape of the active site). As the shape of the active site has changed, the substrate can no longer fit into the active site, which means that the enzyme does not function correctly.