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)

Question

Responses
a b c or d solve it and tell me why
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.

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 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.
Photosynthesis needs a higher amount of energy to activate the reaction because the products are at a lower energy state than the reactants.
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Answer 1

To answer the question, let's first clarify the nature of cellular respiration and photosynthesis in terms of energy and activation energy:

1. Cellular Respiration:

   • Exothermic Reaction: This means that it releases energy (in the form of ATP) as it converts glucose and oxygen into carbon dioxide and water.
   • Products at Lower Energy State: Because energy is released, the products of cellular respiration (CO2 and H2O) are at a lower energy state compared to the reactants (glucose and O2).
   • Activation Energy: Since it is an exothermic reaction, the activation energy required is relatively lower because the reactants have a higher energy state compared to the products.

2. Photosynthesis:

   • Endothermic Reaction: This process requires energy, specifically in the form of sunlight, to convert carbon dioxide and water into glucose and oxygen.
   • Products at Higher Energy State: In photosynthesis, the products (glucose and O2) are at a higher energy state than the reactants (CO2 and H2O) because energy is absorbed.
   • Activation Energy: Since it is an endothermic reaction, photosynthesis typically requires a higher amount of activation energy initially to proceed.

Given this context, we can analyze the responses:

1. Cellular respiration needs a smaller amount of energy to activate the reaction because the products are at a lower energy state than the reactants.

   • This statement is accurate.

2. Photosynthesis needs a smaller amount of energy to activate the reaction because the products are at a lower energy state than the reactants.

   • This statement is incorrect. Photosynthesis requires energy to proceed.

3. Cellular respiration needs a higher amount of energy to activate the reaction because the products are at a lower energy state than the reactants.

   • This statement is incorrect. Cellular respiration requires lower activation energy.

4. Photosynthesis needs a higher amount of energy to activate the reaction because the products are at a lower energy state than the reactants.

   • This statement is also incorrect. Photosynthesis requires higher energy but does not involve products being at a lower energy state.

Thus, the correct response is:

Cellular respiration needs a smaller amount of energy to activate the reaction because the products are at a lower energy state than the reactants.