Select the statements that describe or characterize endergonic reactions. products have more free energy than reactants reactants have more free energy than products requires an input of energy releases energy 2) Select the statements that describe or characterize exergonic reactions. require energy release energy spontaneous not spontaneous 3) Which of the following are characteristics of enzymes? Select all that apply reusable specific needed in small amounts unchanged during reaction
The Correct Answer and Explanation is:
Here are the correct answers:
1) Endergonic Reactions
Select the statements that describe or characterize endergonic reactions:
- ✅ Products have more free energy than reactants
- ✅ Requires an input of energy
Incorrect choices:
- ❌ Reactants have more free energy than products
- ❌ Releases energy
2) Exergonic Reactions
Select the statements that describe or characterize exergonic reactions:
- ✅ Release energy
- ✅ Spontaneous
Incorrect choices:
- ❌ Require energy
- ❌ Not spontaneous
3) Characteristics of Enzymes
Select all that apply:
- ✅ Reusable
- ✅ Specific
- ✅ Needed in small amounts
- ✅ Unchanged during reaction
Explanation
Chemical reactions in biological systems can be categorized based on the flow of energy. Two primary types are endergonic and exergonic reactions.
Endergonic reactions require an input of energy to proceed. This is because the products formed have more free energy than the reactants. Since energy is absorbed from the surroundings, these reactions are not spontaneous and often need coupling with exergonic processes, such as ATP hydrolysis, to occur in cells. A common biological example is the synthesis of glucose molecules during photosynthesis.
In contrast, exergonic reactions involve a release of energy as the reaction proceeds from high-energy reactants to lower-energy products. These reactions are spontaneous and drive many processes in the body, such as cellular respiration. They help in providing the necessary energy to power various cellular functions, including muscle contraction and active transport.
Enzymes, which are biological catalysts, play a critical role in facilitating both endergonic and exergonic reactions. They are specific to the substrates they act upon, ensuring the correct reaction occurs. Enzymes are not consumed in the reaction, so they are reusable. They function effectively in small amounts and remain unchanged at the end of the reaction. By lowering the activation energy needed, enzymes speed up the rate of biochemical reactions without altering the overall energy balance between reactants and products.
Understanding these concepts helps explain how organisms manage energy efficiently and maintain life processes through highly regulated biochemical pathways.
