Difference Between Simple and Complex Carbohydrates

Main Difference – Simple vs Complex Carbohydrates

Simple and complex carbohydrates are the two forms of carbohydrates which are consumed by animals. Carbohydrates are also called starch or sugars. Carbohydrate is a biological molecule composed of carbon (C), hydrogen (H) and oxygen (O) atoms, with a hydrogen to oxygen atom ratio of 2:1. The main difference between simple and complex carbohydrates is that simple carbohydrates are quickly digested and absorbed by the body whereas complex carbohydrates take time to be digested. An adult man should consume less than 70 g of sugars per day and an adult woman should consume less than 50 g of sugars per day.

Key Areas Covered

1. What are Simple Carbohydrates
      – Definition, Digestion, Absorption
2. What are Complex Carbohydrates
      – Definition, Digestion, Absorption
3. What are the Similarities Between Simple and Complex Carbohydrates
      – Outline of Common Features
4. What is Difference Between Simple and Complex Carbohydrates
      – Comparison of Key Differences

Key Terms: Blood Sugar Levels, Complex Carbohydrates, Digestion, Disaccharides, Monosaccharides, Polysaccharides, Simple Carbohydrates

What are Simple Carbohydrates

Simple carbohydrates are carbohydrates that contain single monosaccharide units. They are found in natural food sources such as milk, fruit, and vegetables. Simple sugars give food a sweet taste. The blood glucose levels are elevated by simple sugars since they are easy to digest and are readily absorbed.

Main Difference - Simple vs Complex Carbohydrates

Figure 1: Milk

Monosaccharides and disaccharides are two types of simple carbohydrates. Monosaccharides include glucose, galactose, and fructose. Glucose is a simple sugar that circulates in the bloodstream of animals. Glucose is produced by plants during photosynthesis. Galactose occurs in milk in the form of lactose. Galactose is less sweet than glucose and fructose. Fructose is fruit sugar and mainly occurs in plants. A glucose molecule is shown in figure 2.

Difference Between Simple and Complex Carbohydrates_Figure 2

Figure 2: Glucose

Disaccharides include sucrose, lactose, and maltose. A sucrose molecule is made up of glucose and fructose molecules. Sucrose is the organic compound which is transported by the phloem. Lactose is made up of a glucose and a galactose molecule. Maltose is made up of two glucose molecules. It is produced in the breakdown of starch by amylase.

What are Complex Carbohydrates

Complex carbohydrates are polysaccharides which are made up of hundreds or thousands of monosaccharide units. They are also called polysaccharides. Complex carbohydrates are more slowly digested and take time to absorb to the body. Green vegetables, starchy vegetables such as potatoes and corn, peas, lentils, beans, whole grain and food produced by the whole grain are composed of complex carbohydrates. Some sources of complex carbohydrates are shown in figure 3.

Difference Between Simple and Complex Carbohydrates

Figure 3: Complex Carbohydrates

Usually, the whole grain food raises blood sugar levels more slowly than simple carbohydrates. However, higher levels of polysaccharides may increase the blood glucose levels considerably.

Similarities Between Simple and Complex Carbohydrates

Both simple and complex carbohydrates are two forms of carbohydrates.
Both simple and complex carbohydrates are composed of carbon (C), hydrogen (H) and oxygen (O) atoms.
The ratio of hydrogen to oxygen atom is 2:1 in both simple and complex carbohydrates.

Definition

Simple Carbohydrates: Simple carbohydrates refer to the carbohydrates that contain single monosaccharide units.

Complex Carbohydrates: Complex carbohydrates refer to a polysaccharide that is made up of hundreds or thousands of monosaccharide units.

Digestion

Simple Carbohydrates: Simple carbohydrates are easy to digest.

Complex Carbohydrates: Complex carbohydrates take time to digest.

Types

Simple Carbohydrates: Monosaccharides and disaccharides are types of simple carbohydrates.

Complex Carbohydrates: Polysaccharides such as starch are complex carbohydrates.

Sweetness

Simple Carbohydrates: Simple carbohydrates contain sweetness.

Complex Carbohydrates: Complex carbohydrates are less sweet than simple carbohydrates.

Blood Glucose Levels

Simple Carbohydrates: Simple carbohydrates quickly raise blood glucose levels.

Complex Carbohydrates: Complex carbohydrates slowly raise blood glucose levels.

Conclusion

Simple and complex carbohydrates are the two forms of carbohydrates consumable by animals. Simple carbohydrates are monosaccharides and disaccharides. Complex carbohydrates are polysaccharides such as starch. Simple carbohydrates are easily digestible and absorbable by the body. But, complex carbohydrates take time for digestion. Therefore, the main difference between simple and complex carbohydrates is their complexity.

Reference:

1. “What Are Healthy Simple Carbohydrates?” Healthy Eating | SF Gate, Available here.
2. Hultin, Ginger. “A Complete Guide to Complex Carbohydrates.” LIVESTRONG.COM, Leaf Group, 3 Oct. 2017, Available here.

Image Courtesy:

1. “1887234” (Public Domain) via Pixabay
2. “Glucose-2D-skeletal” (Public Domain) via Commons Wikimedia
3. “Bread and grains” released by the National Cancer Institute – National Institutes of Health (Public Domain) via Commons Wikimedia