Tissues form lactic acid from glucose. This phenomenon is termed as?

SJH Nursing Officer - 2019

Biochemistry & Nutrition

Easy

Appeared in: SJH Nursing Officer - 2019

Explanation

Anaerobic glycolysis is the metabolic pathway that converts glucose into lactate in the absence of sufficient oxygen.
This process occurs in the cytoplasm and is essential for energy production in cells lacking mitochondria (e.g., red blood cells) or in tissues under hypoxic conditions (e.g., intensely exercising muscle).
The key reaction involves the reduction of pyruvate to lactate by lactate dehydrogenase, which regenerates NAD+ needed for glycolysis to continue.
This pathway yields a net of 2 ATP per molecule of glucose, providing a rapid but limited source of energy.

Option A: Aerobic glycolysis requires oxygen and its end product is pyruvate, which is then further oxidized in the mitochondria. It does not produce lactic acid.
Option B: Oxidation is a general chemical term for a reaction involving the loss of electrons. While glycolysis involves oxidation steps, it is not the specific name for the overall process of converting glucose to lactic acid.
Option C: Oxidative phosphorylation is the mitochondrial process that generates the vast majority of ATP in the presence of oxygen. It is the final stage of aerobic respiration and is not involved in the formation of lactate.

Clinical Relevance

Nursing practice connection: Knowing Metabolism of Carbohydrates helps nurses interpret findings accurately and avoid errors in routine assessment, medication administration, and patient teaching.
Understanding anaerobic glycolysis is crucial for nurses as elevated lactate levels (lactic acidosis) are a key indicator of tissue hypoxia, commonly seen in conditions like sepsis, shock, and cardiac arrest.
Nurses monitor lactate levels in critically ill patients to assess tissue perfusion and the effectiveness of interventions like fluid resuscitation and oxygen therapy.
In diabetic patients, particularly those on metformin, there is a small risk of lactic acidosis, and nurses should be aware of the signs and symptoms.

How to Approach the Question

First, identify the key terms in the question: 'lactic acid' and 'glucose'.
Recall the metabolic pathways involving glucose. 'Glycolysis' is the breakdown of glucose.
Differentiate between the two main types of glycolysis based on the end product. The presence of 'lactic acid' is the defining feature of one type.
Associate 'lactic acid' formation with conditions of low or no oxygen ('anaerobic').
Evaluate the options: 'Aerobic' means with oxygen. 'Oxidation' and 'Oxidative Phosphorylation' are related but distinct processes. 'Anaerobic Glycolysis' directly describes glucose breakdown to lactate without oxygen.
Conclude that the formation of lactic acid from glucose is termed anaerobic glycolysis.

Concept Tested & Keywords

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E6 Harper's Illustrated Biochemistry2023 (pp 26-793 of 813) p. 151-153

E6 Textbook of Biochemistry for medical StudentsDM Vasudevan Part 1 (pp 26-370 of 370) p. 148-150

E6 Biochemistry U Satyanarayana— Part 1 (pp 26-420 of 840) p. 239-241