all the information provided to the student Key concepts - When ATP is hydrolyzed to ADP + P i , energy that is usable for a cell is released - Through coupling reactions, ATP drives endergonic reactions using energy derived from exergonic reactions. - Catalysts speed up the rate of a reaction but do not allow the occurrence of a reaction that would not otherwise take place. - An enzyme may undergo a change in shape called induced fit as the result of binding its substrate. - Environmental factors such as pH and temperature affect enzyme activity. Introduction Many people enjoy watching and catching fireflies on warm summer nights, but the attraction isn't mutual; a firefly's primary goal with its impressive light show is to find a mate. Male and female fireflies use specific patterns of light flashes to attract one another. The flashes are emitted from the firefly lantern, an organ located in the firefly abdomen. Light is a form of energy, which means that fireflies must divert some of their energy to produce these light flashes. Researchers used a biochemical approach to learn how this is done. When the lanterns of fireflies are ground up and extracted with water, the extract briefly produces an intense light, which then fades away. If ATP is added to the extract, light is again emitted, and again, it fades. The graph below shows the duration of light emission as a function of the amount of ATP added. When anaerobic conditions were used, no light was observed. Through additional investigations, the researchers discovered that light was produced because of a chemical reaction involving a compound called luciferin. The researchers again examined the lantern cell extracts and purified Luciferase, the enzyme that catalyzes the reaction by which luciferin emits light. The researchers also observed how, when mixed with a fixed amount of Luciferase, varying the abundance of luciferin, ATP, and magnesium ( Mg 2 + ) resulted in different amounts of light (light intensity). The table below shows light intensity as each variable changed. 1. Based on these data, what molecules are necessary to produce light by firefly lanterns? What role does each molecule serve? 2. Explain how energy taken in by the firefly from its environment is made available for the production of light in a firefly lantern. 3. Additional research has shown that an activated intermediate forms at the active site of the enzyme as luciferin reacts. This intermediate consists of luciferin covalently bonded to adenosine monophosphate (AMP). Still at the active site, this intermediate then reacts with oxygen to make an oxidized form of luciferin with the emission of light. The diagram below shows these steps. Redraw the diagram, adding steps to illustrate how coupling reactions could be involved to provide the energy needed for light emission. 4. What evidence is there that the enzyme is sensitive to environmental factors? Suggest possible reasons why this enzyme responds as it does to .

1. all the information provided to the student
Key concepts - When ATP is hydrolyzed to ADP + P i , energy that is usable for a cell is
released - Through coupling reactions, ATP drives endergonic reactions using energy derived
from exergonic reactions. - Catalysts speed up the rate of a reaction but do not allow the
occurrence of a reaction that would not otherwise take place. - An enzyme may undergo a
change in shape called induced fit as the result of binding its substrate. - Environmental factors
such as pH and temperature affect enzyme activity. Introduction Many people enjoy watching
and catching fireflies on warm summer nights, but the attraction isn't mutual; a firefly's primary
goal with its impressive light show is to find a mate. Male and female fireflies use specific
patterns of light flashes to attract one another. The flashes are emitted from the firefly lantern, an
organ located in the firefly abdomen. Light is a form of energy, which means that fireflies must
divert some of their energy to produce these light flashes. Researchers used a biochemical
approach to learn how this is done. When the lanterns of fireflies are ground up and extracted
with water, the extract briefly produces an intense light, which then fades away. If ATP is added
to the extract, light is again emitted, and again, it fades. The graph below shows the duration of
light emission as a function of the amount of ATP added. When anaerobic conditions were used,
no light was observed. Through additional investigations, the researchers discovered that light
was produced because of a chemical reaction involving a compound called luciferin. The
researchers again examined the lantern cell extracts and purified Luciferase, the enzyme that
catalyzes the reaction by which luciferin emits light. The researchers also observed how, when
mixed with a fixed amount of Luciferase, varying the abundance of luciferin, ATP, and
magnesium ( Mg 2 + ) resulted in different amounts of light (light intensity). The table below
shows light intensity as each variable changed. 1. Based on these data, what molecules are
necessary to produce light by firefly lanterns? What role does each molecule serve? 2. Explain
how energy taken in by the firefly from its environment is made available for the production of
light in a firefly lantern. 3. Additional research has shown that an activated intermediate forms at
the active site of the enzyme as luciferin reacts. This intermediate consists of luciferin covalently
bonded to adenosine monophosphate (AMP). Still at the active site, this intermediate then reacts
with oxygen to make an oxidized form of luciferin with the emission of light. The diagram below
shows these steps. Redraw the diagram, adding steps to illustrate how coupling reactions could
be involved to provide the energy needed for light emission. 4. What evidence is there that the
enzyme is sensitive to environmental factors? Suggest possible reasons why this enzyme
responds as it does to these factors? 5. Some studies have shown that the enzyme undergoes a
shape change upon binding ATP and luciferin. This change makes it impossible for a molecule
of water to fit into the active site along with the substrates. What property of an enzyme does this
represent, and how does this property help this particular enzyme carry out its role in catalysis?