Question

Which of the following statements best describes a metabolic pathway?

1.the set of molecular reactions in which enzymes make or break down sugars

2.chemical reactions that do not involve the use of enzymes and that maintain homeostasis

3.a chemical reaction that makes or breaks down molecules

4.a linked sequence of chemical reactions catalyzed by specific enzymes

Answer 1

Metabolic pathway: Any of the sequences of biochemical reactions, catalyzed by enzymes, that occur in all living cells: concerned mainly with the exchange of energy and chemicals is termed as the metabolic pathway.

E.g. Photosynthesis in plants, Glucose breakdown in cell etc. are metabolic reactions

1. Yes, It is the set of molecular reactions in which enzymes make or break down not only sugar sugars but also proteins, fats, DNA and RNA etc.

2. No, chemical reactions in metabolic path way do involve the use of enzymes which increases rate and efficiency of these reactions by lowering the activation energy.

3. Yes, its a chemical reaction that makes or breaks down molecules but not on its own accord.

4. Yes, metabolic pathway involves linked sequence of chemical reactions catalyzed by specific enzymes. Enzymes are very specific in there action. Given enzyme catalyzes a particular biochemical reaction only.

Hence the 4^th statement, “a linked sequence of chemical reactions catalyzed by specific enzymes” best describes the metabolic pathway.

Note: Other statement are either wrong or incomplete. They are corrected and/or added with more information here.

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