WorksheetsIB HL - Enzymes & Metabolism Intro
Total questions: 15
Worksheet time: 8mins
Which of the following describes the active site?
the part of an enzyme that binds only to the product molecules
the sequence of amino acids responsible for the catalytic activity of enzymes
the sequence of amino acids responsible for the structure of an enzyme
the specific area responsible for the activity of all proteins
What determines the specificity of an enzyme for its substrate?
the temperature at which is it operating
the optimum pH of the enzymes
the concentration of the substrate
the structure of the enzyme molecule
Which levels of protein structure can determine the specificity of an enzyme?
primary
secondary
tertiary
primary
secondary
tertiary
quaternary
tertiary
quaternary
primary
secondary
quaternary
Which of the following determines the specificity of an enzyme?
1 - the bonding between the R groups of the polypeptide
2 - the optimum pH of the enzyme
3 - the peptide bonds between animo acids of the polypeptide
4 - the shape of the substrate molecule
1, 2, 3 and 4
1 and 3 only
1 only
2, 3 and 4 only
According to the induced fit model of enzyme function,
which of the following statements is correct?
active sites on enzymes are specific to a single substrate
the shape of the active site can be changed by the binding of an allosteric inhibitor
the binding of the substrate changes the shape of the active site slightly
competitive inhibitors can change the shape of enzymes
Which of the following statements are correct for the induced fit hypothesis?
1 - folding of an enzyme molecule causes the formation of the active site
2 - the shape of the active site changes to enable the substrate to bind
3 - temporary bonds hold the substrate in the active site
4 - more ES complexes are formed at the optimum temperature
1 and 2
1 and 3
2, 3 and 4
2 and 4
Which of the following statements is true about enzymes?
they lower the energy of activation for a reaction
allosteric inhibitors bind to the active site
they are used up in the reactions they catalyse
they supply the energy of activation for a reaction
Which statement is true of all enzymes?
they are denatured at temperatures above 60°C
they are inactivated at low pH values
they catalyse the breakdown of large molecules into smaller ones
they reduce the amount of energy required to start a reaction
The graph shows the activation energy of an enzyme catalysed reaction and the same reaction without a catalyst.
Which arrow shows the activation energy of the uncatalysed reaction?
A
B
C
D
The diagram shows the energy changes in a chemical reaction. What would happen to the changes in energy if this reaction was controlled by an enzyme?
I would increase
II would decrease
I and IV would decrease
II and III would decrease
The graph shows the effect of an enzyme on a reaction. Which labels are correct?
X is the reaction without the enzyme, W is the activation energy.
X is the reaction with the enzyme, Z is the overall energy change.
Y is the reaction with the enzyme, W is the difference in activation energy.
Z is the energy gained by the product, W is the activation energy with the enzyme.
Which reaction is an example of catabolism?
Photolysis of water
Denaturation of a protein by a change in pH
Production of maltose from amylose by amylase
Condensation of glucose to form starch
Which type of chemical reaction is an example of anabolism?
Combustion
Condensation
Hydrolysis
Photolysis
In which processes are macromolecules broken down into monomers?
Anabolism and catabolism
Catabolism and hydrolysis
Hydrolysis and reduction
Reduction and anabolism
The equation shows a reversible reaction. In this reaction, on which molecule does an active site occur and what types of reaction occur at 1 and 2?
active site on sucrase
1 = hydrolysis
2 = condensation
active site on sucrase
1 = condensation
2 = hydrolysis
active site on sucrose
1 = hydrolysis
2 = condensation
active site on sucrose
1 = condensation
2 = hydrolysis
