Which of the following processes involves the conversion of glucose to energy in the cells?

DSSSB 12 August 2024

Biochemistry & Nutrition

Easy

Appeared in: DSSSB 12 August 2024

Explanation

Glycolysis is the universal metabolic pathway that breaks down a six-carbon glucose molecule into two three-carbon molecules of pyruvate.
This process occurs in the cytoplasm of all living cells and does not require oxygen.
Glycolysis results in a net production of ATP (adenosine triphosphate), which is the primary energy currency used by cells to power various biological processes.
It is the foundational and initial step of cellular respiration, providing the raw materials for subsequent energy-producing pathways like the citric acid cycle.

Option A: Fermentation is an anaerobic process that occurs after glycolysis in the absence of oxygen. Its primary purpose is not to produce energy from glucose, but to regenerate NAD+ from the NADH produced during glycolysis, allowing glycolysis to continue.
Option B: Photosynthesis is the process used by plants, algae, and some bacteria to convert light energy into chemical energy in the form of glucose. It creates glucose, whereas the question asks about breaking down glucose for energy.
Option D: Oxidation is a very general chemical term referring to the loss of electrons. While glucose is indeed oxidized during glycolysis and subsequent stages of cellular respiration, 'oxidation' is not the specific name of the metabolic pathway itself.

Clinical Relevance

Nursing practice connection: Knowing Glucose Metabolism and Cellular Energy Production helps nurses interpret findings accurately and avoid errors in routine assessment, medication administration, and patient teaching.
Understanding glycolysis is fundamental in nursing for comprehending metabolic disorders like diabetes mellitus, where cellular uptake and metabolism of glucose are impaired.
During high-intensity exercise, muscles rely on anaerobic glycolysis for rapid energy, leading to the production of lactate. This is clinically relevant for understanding muscle fatigue and acidosis.
Many cancer cells exhibit abnormally high rates of glycolysis (the Warburg effect), a principle used in diagnostic imaging (e.g., PET scans with FDG) and as a target for therapies.

How to Approach the Question

First, identify the core concept of the question, which is the cellular process for converting glucose into energy.
Analyze the keywords: 'glucose', 'conversion', 'energy', 'cells'. This points towards cellular respiration.
Evaluate each option: 'Photosynthesis' is the opposite process (making glucose). 'Fermentation' is a related but secondary process that happens in the absence of oxygen. 'Oxidation' is a general chemical term, not a specific metabolic pathway.
Recall the definition of 'Glycolysis' as the specific, initial pathway that breaks down glucose in the cytoplasm to produce ATP.
Conclude that Glycolysis is the most precise and accurate answer that describes the initial conversion of glucose to energy in a cell.

Concept Tested & Keywords

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

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