Which statement best explains how enzymes speed up chemical reactions?
question options:

a. enzymes lower the activation energy of a reaction.

b. enzymes gain heat from chemical reactions.

c. enzymes change shape during chemical reactions.

d. enzymes use light energy to speed up chemical reactions.

The correct option is A) Enzymes lower the activation energy of a reaction.

Enzymes are also called as catalyst. They increase the rate of reaction by lowering the activation energy of the reaction. This means that they speed up the chemical reactions by doing so.

Activation energy is the minimum amount of energy required by a reactant to form an activated complex in order to initiate the chemical or nuclear reaction.

Thus, enzymes speed up the chemical reactions by lowering the activation energy.

european union policies. the eu's long-term objective is to achieve levels of air quality that do not result in unacceptable impacts on, and risks to, human health and the environment. eu policies aim to reduce exposure to air pollution by reducing emissions and setting limits and target values for air quality.

the main environmental problems in western europe were: energy production/acid rain, nuclear power/waste, air pollution/climate, heavy metals, pesticides, water pollution, solid waste, and unforeseen accidents. many environmental problems are common to most european countries.

sulfur dioxide

explanation: acid rain is caused by a chemical reaction that begins when compounds like sulfur dioxide and nitrogen oxides are released into the air. these substances can rise very high into the atmosphere, where they mix and react with water, oxygen, and other chemicals to form more acidic pollutants, known as acid rain.