The Role of Enzymes Quick Check
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Question
Cellular respiration is an exothermic reaction and photosynthesis is an endothermic reaction. How does the required activation energy compare for these two reactions?(1 point)
Responses
Photosynthesis needs a smaller amount of energy to activate the reaction because the products are at a lower energy state than the reactants.
Photosynthesis needs a smaller amount of energy to activate the reaction because the products are at a lower energy state than the reactants.
Cellular respiration needs a smaller amount of energy to activate the reaction because the products are at a lower energy state than the reactants.
Cellular respiration needs a smaller amount of energy to activate the reaction because the products are at a lower energy state than the reactants.
Cellular respiration needs a higher amount of energy to activate the reaction because the products are at a lower energy state than the reactants.
Cellular respiration needs a higher amount of energy to activate the reaction because the products are at a lower energy state than the reactants.
Photosynthesis needs a higher amount of energy to activate the reaction because the products are at a lower energy state than the reactants.
They lower activation energy.
The chemical reaction will not occur, and the body will not be able to absorb the protein it needs.
How do enzymes affect chemical reactions?(1 point)
Responses

They eliminate activation energy.
They eliminate activation energy.

They provide activation energy.
They provide activation energy.

They increase activation energy.
They increase activation energy.

They lower activation energy.
The Role of Enzymes Quick Check
3 of 53 of 5 Items

Question
Which lists the correct order of steps involved in the formation of an enzyme-substrate complex?(1 point)
Responses

enzyme binds to substrate at active site > chemical reaction takes place > products are released > enzyme-substrate complex forms
enzyme binds to substrate at active site > chemical reaction takes place > products are released > enzyme-substrate complex forms

enzyme-substrate complex forms > enzyme binds to substrate at active site > chemical reaction takes place > products are released
enzyme-substrate complex forms > enzyme binds to substrate at active site > chemical reaction takes place > products are released

chemical reaction takes place > products are released > enzyme binds to substrate at active site > enzyme-substrate complex forms
chemical reaction takes place > products are released > enzyme binds to substrate at active site > enzyme-substrate complex forms

enzyme binds to substrate at active site > enzyme-substrate complex forms > chemical reaction takes
enzyme binds to substrate at active site > enzyme-substrate complex forms > chemical reaction takes place > products are released
Protease is an enzyme in the human body that catalyzes a chemical reaction in which proteins are broken down into smaller molecules so that the body can use them. Which is a likely outcome if protease does not function properly?(1 point)
Responses

The cells of the digestive system will increase in temperature and catalyze the reaction.
The cells of the digestive system will increase in temperature and catalyze the reaction.

The activation energy needed for the chemical reaction will be lowered.
The activation energy needed for the chemical reaction will be lowered.

The chemical reaction will not occur, and the body will not be able to absorb the protein it needs.
The chemical reaction will not occur, and the body will not be able to absorb the protein it needs.

The body will use a different enzyme to catalyze the chemical reaction.
The body will use a different enzyme to catalyze the chemical reaction.
How does temperature affect enzyme activity in a chemical reaction?(1 point)
Responses

The rate of a chemical reaction initially increases with increasing temperature and continues to increase indefinitely as temperature continues to increase.
The rate of a chemical reaction initially increases with increasing temperature and continues to increase indefinitely as temperature continues to increase.

The rate of a chemical reaction initially increases with increasing temperature and then decreases, eventually stopping, when the temperature gets too high.
The rate of a chemical reaction initially increases with increasing temperature and then decreases, eventually stopping, when the temperature gets too high.

The rate of a chemical reaction always decreases with increasing temperature and always increases with decreasing temperature.
The rate of a chemical reaction always decreases with increasing temperature and always increases with decreasing temperature.

The rate of a chemical reaction initially increases with decreasing temperature and then decreases, eventually stopping, when the temperature gets too low.
The rate of a chemical reaction initially increases with increasing temperature and then decreases, eventually stopping, when the temperature gets too high.
To determine how the required activation energy compares for cellular respiration and photosynthesis, we need to understand the concept of activation energy. Activation energy is the minimum amount of energy required for a chemical reaction to occur.
In cellular respiration, which is an exothermic reaction, energy is released as a result. The reactants (such as glucose) have a higher energy state than the products (such as carbon dioxide and water). Since the products are at a lower energy state than the reactants, cellular respiration needs a lower amount of energy to activate the reaction.
On the other hand, in photosynthesis, which is an endothermic reaction, energy is absorbed during the process. The reactants (such as carbon dioxide and water) have a lower energy state than the products (such as glucose and oxygen). Consequently, because the products are at a higher energy state than the reactants, photosynthesis needs a higher amount of energy to activate the reaction.
Therefore, the correct response is: Photosynthesis needs a higher amount of energy to activate the reaction because the products are at a lower energy state than the reactants