& x20;What is the role of a buffer in a chemical reaction?

Change the color of the solution

NORCET 1 - 2020

Biochemistry & Nutrition

Easy

What is the role of a buffer in a chemical reaction?

Appeared in: NORCET 1 - 2020

A buffer is a solution that resists significant changes in pH upon the addition of small amounts of an acid or a base.
It functions by having a mixture of a weak acid and its conjugate base (or a weak base and its conjugate acid) that can neutralize added H+ or OH- ions.
This mechanism is essential for maintaining homeostasis in biological systems, such as keeping the blood pH within the narrow, life-sustaining range of 7.35-7.45.

Option A: This describes the function of a catalyst, not a buffer. Catalysts alter the rate of a reaction but do not stabilize pH.
Option B: This describes the function of an inhibitor. Inhibitors decrease the rate of a chemical reaction.
Option D: This describes a pH indicator. Indicators change color to visually signal the pH of a solution but do not have the capacity to stabilize it.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Function of a buffer solution in chemistry and physiology as background academic context rather than a clinical decision trigger.
The human body's buffer systems (bicarbonate, phosphate, protein) are the first line of defense in maintaining blood pH within the critical range of 7.35 to 7.45.
Nurses frequently interpret Arterial Blood Gas (ABG) results to assess a patient's acid-base status, which directly reflects the function and capacity of these vital buffer systems.
What if? A patient with diabetic ketoacidosis (DKA) has a blood pH of 7.20. This indicates the body's bicarbonate buffer system is overwhelmed by excess ketoacids, leading to metabolic acidosis. The priority nursing action is to administer insulin and fluids as prescribed to correct the underlying metabolic problem, which in turn helps restore the acid-base balance.

How to Approach the Question

First, identify the core concept in the question: the 'role of a buffer'.
This is a factual recall question based on a fundamental concept in chemistry and physiology.
Evaluate each option based on its scientific definition.
Option A (speed up) and Option B (slow down) relate to reaction kinetics and describe catalysts and inhibitors, respectively.
Option D (change color) describes a pH indicator, which is used for measurement, not stabilization.
Option C (maintain a stable pH) is the precise definition of a buffer's function. Select this as the correct answer.

Concept Tested & Keywords

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E6 Textbook of Biochemistry for medical StudentsDM Vasudevan Part 2 — Subpart A (pp 1-239 of 478) pp. 71-73, 72-74

E6 Physiology Ganong 27e Vol 1 Part 1 p. 13-15

Practise the full NORCET 1 - 2020

Attempt every question from this paper in a timed mock, then review the full solution for each one.