Practise IB Biology HL C1.1 by explaining enzyme specificity, metabolic reactions, rate evidence, inhibition and feedback control in biological pathways.
Outline the action of enzymes.
Identify the following processes as either anabolism or catabolism by placing a tick ( ✓ ) in the correct box.
Outline the importance of enzymes to metabolic processes.
What is an example of anabolism?
Formation of peptides after protein digestion
Formation of glucose and fructose from sucrose
Formation of maltose from two glucose molecules
Formation of glycerol and fatty acids from triglycerides
Outline the importance of enzymes to metabolic processes.
Define the active site of an enzyme.
Describe the lock and key model of enzyme activity and how the induced fit model extends it.
Explain how the active site promotes enzyme-substrate specificity.
Cholinergic synapses use acetylcholine as their neurotransmitter. They are widespread in the body, passing on signals to muscle cells. These synapses are affected by neonicotinoid pesticides.
The diagrams, which are not drawn to scale, show the synapse between two neurons and a detail of the synaptic cleft.
Explain what happens to an enzyme if there is a change of pH .
Laccase is an enzyme that has the ability to decompose synthetic dyes used in the production of clothing and thus could potentially help reduce synthetic dye pollution.
An experiment was performed in which laccase was immobilized in alginate beads to determine the effectiveness of laccase immobilization in decolorizing the dye crystal violet. The graph shows the effect of laccase concentration on relative decolorization activity of the immobilized laccase. Error bars represent ± SD.
Deduce the significance of overlapping error bars in the data for laccase concentrations from to .
Discuss the variables that need to be controlled in this investigation.
Suggest how the percentage of decolorization could be obtained experimentally.
(a) The image shows a cell in a section of an onion root tip seen under a light microscope.
The graph shows energy levels throughout an uncatalysed reaction. Draw a curve to show how the action of an enzyme would affect this reaction.
What is an example of an intracellular enzyme-catalysed reaction?
Chemical digestion in the gut
Glycolysis in cellular respiration
Blood clotting in the circulatory system
Recycling of acetylcholine in a synapse
Common bottlenose dolphins, Tursiops truncatus, are marine mammals of temperate and tropical oceans throughout the world, where they feed on fish, squid and crustaceans.
Research has been carried out on a population of these dolphins in Sarasota Bay, Florida. The table shows the mean sea surface temperature in Sarasota Bay and catch per unit effort (CPUE) in winter and summer. A large CPUE indicates it would take little effort for the dolphin to catch a lot of prey.
Explain the differences in BMR between desert and polar mammals up to a mass of .
Above a body mass of 10 kg , there is little difference in BMR between desert and polar mammals.
Suggest reasons for this.
Laccase is an enzyme that has the ability to decompose synthetic dyes used in the production of clothing and thus could potentially help reduce synthetic dye pollution.
An experiment was performed in which laccase was immobilized in alginate beads to determine the effectiveness of laccase immobilization in decolorizing the dye crystal violet. The graph shows the effect of laccase concentration on relative decolorization activity of the immobilized laccase. Error bars represent ± SD.
Distinguish between processes involved in cyclical and linear metabolic pathways.
The dashed line shows the relationship between the activity of an enzyme and the concentration of its substrate. Which curve shows the effect of a non-competitive inhibitor on this relationship?
Interactions in biological systems may have harmful or beneficial effects.
Explain, using an example, how competitive inhibitors interfere with enzyme activity.
Feedback mechanisms are used in living organisms both to promote and respond to change.
Explain the regulation of metabolic pathways by end-product inhibition.