Metabolism (DP IB Biology: HL)

Which of the following statements about metabolism are correct?

1. Metabolism involves chemicals called metabolites.
2. Metabolism involves reactions in a linear chain.
3. Metabolism involves reactions in a cycle.
4. Metabolism involves only the breakdown of molecules.

Which of the following is not a correct description of the “transition state” in enzyme-controlled reactions?

The graph below shows the energy changes during a reaction.

What effect would adding an enzyme have on the energy changes of the reaction?

What is the difference between a competitive and non-competitive inhibitor?

Cyanide ions are an example of an allosteric inhibitor that targets the enzyme cytochrome c oxidase in aerobic respiration.

Which row best describes the action of cyanide ions?

Isoleucine can be described as an end-product inhibitor.

Which statement best describes the action of isoleucine?

The protein sequence of an enzyme involved in the Plasmodium parasite’s metabolism has been identified in order to support research into anti-malarial drugs.

Which terms best fill the gaps in the sentence about Plasmodium parasite research below?         

Bioinformatics can be used to screen ………I……….. against a database of chemicals to identify potential ………II………..

Which graph shows the rate of a reaction taking place in the presence of a competitive inhibitor compared to the rate of a reaction in the absence of an inhibitor?

The table below gives information on the rates of several enzyme-catalysed reactions.

Which enzyme catalyses the reaction with the fastest rate of product formation?

Which statement best describes how to calculate the initial rate of a reaction from a graph such as the one below?

This diagram shows a metabolic pathway occurring in an organelle. The speed of this metabolic pathway is self-regulating as the end product acts as a competitive inhibitor to enzyme 2. 

What would you expect not to occur when adding an additional end product to the organelle?

In the graph, Z represents the relationship between the initial rate of an enzyme-catalysed reaction and the concentration of its substrate under optimal conditions and without an inhibitor.

Which curve would represent the same experiment carried out in the presence of a low concentration of a non-competitive inhibitor?

The graphs in A - D show the progress of an enzyme-catalysed reaction, measured by the volume of product released from the reaction mixture over time. 

Which graph best depicts how a scientist would establish the average rate of reaction over the first minute of the reaction?

The following six statements are steps in using bioinformatics to find potential cures for malaria, one of the most serious infectious diseases that humans face. The steps are not listed in the correct order below. 

1. Computer modelling of candidate molecules to identify strong candidates

2. Determining the malaria parasite's proteome

3. Identifying candidate molecules that could inhibit malaria parasite enzymes

4. Sequencing the malaria parasite's genome

5. Drug trials to establish safety and efficacy 

6. Identification of malaria parasite enzymes that could be targets

Which of A - D places the statements into chronological order?

The enzyme catalase was added to a large volume of hydrogen peroxide solution. The volume of oxygen produced in the first five seconds was measured at 250 cm³. 

What is the initial rate of reaction in dm³ min^-1 ?