The proteins that catalyze biochemical reactions are called:

UPUMS Nsg officer-2023

Biochemistry & Nutrition

Easy

Appeared in: UPUMS Nsg officer-2023

Explanation

Enzymes are defined as biological catalysts, which are molecules that significantly speed up the rate of biochemical reactions.
The vast majority of enzymes are proteins, although some RNA molecules (ribozymes) can also act as catalysts.
Their catalytic function is essential for all metabolic processes, from digesting food to synthesizing DNA.
Enzymes work by lowering the activation energy required for a reaction to occur, allowing it to proceed much faster than it would otherwise.

Option A: A polypeptide is a structural term for a chain of amino acids. While enzymes are made of polypeptides, not all polypeptides have the catalytic function of an enzyme.
Option B: Amino acids are the basic building blocks (monomers) of proteins. They do not have catalytic activity on their own.
Option D: Hormones are chemical messengers involved in signaling and regulation. Although some are proteins, their primary function is not catalysis.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Definition and function of enzymes as background academic context rather than a clinical decision trigger.
Measuring the levels of specific enzymes in the blood is a fundamental diagnostic tool in medicine. For instance, elevated levels of creatine kinase (CK-MB) and troponins are biomarkers for myocardial infarction (heart attack).
High levels of serum amylase and lipase are indicative of pancreatitis, while elevated alanine aminotransferase (ALT) and aspartate aminotransferase (AST) point towards liver damage.
Many genetic diseases, known as inborn errors of metabolism (e.g., phenylketonuria), are caused by deficient or non-functional enzymes, leading to the buildup of toxic substances.

How to Approach the Question

First, analyze the question to identify the key concepts. The question is asking for the specific name of 'proteins' that 'catalyze' (speed up) 'biochemical reactions'.
Consider each option in the context of this definition.
Evaluate 'Amino acids': These are the building blocks of proteins, not the functional catalysts themselves. Eliminate this option.
Evaluate 'Polypeptide': This is a chain of amino acids. While enzymes are made of polypeptides, this term describes the structure, not the specific catalytic function. It's too general.
Evaluate 'Hormones': These are signaling molecules. Their function is regulation, not catalysis. Eliminate this option.
Evaluate 'Enzymes': This is the specific term for biological catalysts, which are almost all proteins. This directly matches the definition in the question.

Concept Tested & Keywords

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E6 textbook of Applied Biochemistry and Nutrition & DieteticsHarbans Lal (pp 26-464 of 479) p. 126-128

E6 Biochemistry U Satyanarayana— Part 1 (pp 26-420 of 840) p. 75-77

E6 Harper's Illustrated Biochemistry2023 (pp 26-793 of 813) p. 44-46