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BI3.1-6 | Introduction to Chemistry and Metabolism of Carbohydrates
Learning Objectives
- Classify carbohydrates into monosaccharides, disaccharides, and polysaccharides with examples, and explain their roles as energy fuel, structural elements, and storage molecules (BI3.1)
- Describe the digestion, absorption, and transport of dietary carbohydrates and their disorders (BI3.2)
- Define and describe the major pathways of carbohydrate metabolism — glycolysis, TCA cycle, gluconeogenesis, glycogen metabolism, and HMP shunt — and their regulation (BI3.3)
- Describe the minor carbohydrate metabolism pathways (polyol pathway, galactose metabolism, fructose metabolism) and their associated disorders (BI3.4)
- Explain blood glucose regulation (glucose homeostasis) in health and disease, including types, biochemical changes, complications, and laboratory investigations of diabetes mellitus (BI3.5)
- Interpret laboratory results of analytes associated with carbohydrate metabolism disorders (BI3.6)
INSTRUCTIONS
Every cell in your body runs on glucose. When blood sugar drops below 50 mg/dL, you lose consciousness in minutes. When it stays above 200 mg/dL for years, it destroys your kidneys, eyes, and nerves. This is diabetes — and understanding carbohydrate metabolism is how you'll manage it.
This module takes you from the sugar in your chai to the ATP in your cells: classification of carbohydrates → digestion and absorption → glycolysis (the 10-step universal pathway) → TCA cycle (the final common pathway) → gluconeogenesis (making glucose when you haven't eaten) → glycogen metabolism (your glucose buffer) → diabetes (the clinical payoff).
Parallel connections: In Physiology, you're studying the cardiovascular system — the heart muscle gets 70% of its energy from fatty acids, but during intense exercise, it switches to glucose. In Anatomy, you learned about bone marrow — the red blood cells produced there depend ENTIRELY on glucose (they have no mitochondria, so glycolysis is their only energy source).
References
- Harper's Illustrated Biochemistry, 31st ed., Chapters 15–20: Carbohydrate Metabolism (textbook)
- Lehninger Principles of Biochemistry, 8th ed., Chapters 14–16: Glycolysis, TCA Cycle, Gluconeogenesis (textbook)
- Vasudevan's Textbook of Biochemistry for Medical Students, 10th ed., Chapters 9–12 (textbook)
- OpenStax Biology 2e, Chapter 7: Cellular Respiration (CC BY 4.0) (textbook (CC BY 4.0))
Version 2.0 | NMC CBUC 2024, Adapted from OpenStax Biology 2e (CC BY 4.0)