The correct answer is Option (2) → (A), (C) and (D) only
To identify the correct choice, let's examine the properties of enzymes:
- (A) It is a biocatalyst: Correct. Enzymes are biological catalysts that speed up chemical reactions in living organisms without being consumed in the process. They allow life-sustaining reactions to occur at rates that would otherwise be too slow.
- (B) It can catalyze any chemical reaction: Incorrect. Enzymes are highly specific. Due to the unique shape of their active sites (the "Lock and Key" model), an enzyme typically catalyzes only one specific chemical reaction or a group of very similar reactions. For example, sucrase only breaks down sucrose and will not act on other sugars like lactose.
- (C) Almost all enzymes are globular proteins: Correct. Most enzymes are composed of long chains of amino acids that fold into complex, three-dimensional globular shapes. This specific folding creates the active site where the substrate binds. (Note: A few exceptions exist, such as ribozymes, which are made of RNA, but "almost all" correctly describes the protein-based majority).
- (D) They reduce the magnitude of activation energy: Correct. Enzymes work by providing an alternative pathway for the reaction that has a lower activation energy ($E_a$). By lowering the energy barrier required for reactants to turn into products, the reaction can proceed much faster at body temperature.
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