Question

Choose from the following list of words to complete the paragraph below. Not all terms will be used, and none of them can be used more than once.

positive     intermediate     free   negative   substrate   product   activation   thermal

An enzyme reduces the_____________ energy of a reaction, causing it to occur more frequently at a given temperature than it would otherwise. This does not alter the________ energy of the reactants or products. If the ΔG of a reaction is____________ , the reaction is spontaneous. Reactions that have a common____________ and are part of the same pathway are energetically coupled since the  ΔG for the pathway is the sum of the  ΔGs of the individual reactions.

Answer 1

1- Enzymes are generally proteins that are used to carry out many metabolic reactions. The main function of the enzyme that it lowers down the activation energy due to which the reactants can be easily converted into the products. It reduces the threshold energy required for the conversion of the reactants into products.

2- Free energy is the energy that the reactants have like the reactant releases the energy when the reaction is exothermic and the energy is absorbed in the case of the endothermic reactions. Enzyme does not affect the free energy of the reactions. Thus the blank can be filled with Free energy.

3- Exothermic reactions are spontaneous reactions that mean the reactants have more free energy than the products. In the case of spontaneous reactions, a reaction is negative because more energy is released when there is the conversion of the reactants in the products. Hence, the blank can be filled with negative.

4- Those reactions which have the common substrate and a part of common pathway the free energy of the reaction will be couples and it is calculated by the addition of ΔG of both individual reactions.

Hence the blanks can be filled in this order-

1. Activation

2. Free energy

3. Negative

4. Substrate