lecture recording on 17 February 2025 at 20.42.40 PM

Learning Outcomes

• Identify the two major kinds of carbohydrates in human diets.

• Explain how plants make carbohydrates.

• Identify roles of carbohydrates in the body.

Introduction to Carbohydrates

• Carbohydrates are essential nutrients that are often associated with sweets and energy.

• Many individuals, including infants, have a natural preference for the sweet taste of carbohydrates, as they provide energy that cells need to function.

• Carbohydrates are a class of nutrients primarily utilized for energy by cells in the body.

Types of Carbohydrates

Simple Carbohydrates

• Monosaccharides:

  • Units with one sugar molecule.

  • Examples:

    • Glucose: Sugar found in blood.

    • Fructose: Sugar found in fruits.

    • Galactose: Part of milk sugar.

• Disaccharides:

  • Formed by two monosaccharides linked together.

  • Examples:

    • Maltose: Malt sugar.

    • Sucrose: Table sugar (glucose + fructose).

    • Lactose: Milk sugar (glucose + galactose).

Complex Carbohydrates

• Polysaccharides:

  • Long chains of monosaccharides linked together.

  • Examples:

    • Starch: Storage form of glucose in plants (e.g., potatoes).

    • Glycogen: Storage form in humans and animals, found in liver and muscle cells.

    • Dietary Fiber: Composed of glucose molecules linked in a way that humans cannot digest, beneficial for health.

Carbohydrates in Plants

• Plants manufacture carbohydrates through the process of photosynthesis, combining sunlight, carbon dioxide, and water.

• Photosynthesis:

  • Converts light energy into chemical energy stored in carbohydrates.

  • Produces glucose or fructose as primary sugars, and oxygen as a byproduct.

  • Sucrose is the primary sugar transported within plants.

Importance of Carbohydrates in the Body

• Carbohydrates play crucial roles in energy provision and overall bodily functions.

• Glucose is vital for providing energy necessary for cellular processes, muscle contractions, and synthesizing vital compounds.

Nutritional Considerations

• The average American consumed about 72 pounds of caloric sweeteners in 2021, including honey, maple syrup, and refined sugars.

• While some glucose is necessary, excessive consumption of carbohydrates and added sugars can lead to increased body fat and other health issues.

Conclusion

• Understanding the types and functions of carbohydrates is essential for making informed dietary choices.

• Recognizing how plants create carbohydrates helps appreciate their role in the food chain and human nutrition.