The key difference between carbohydrates and starch is that carbohydrates can be polymeric or non-polymeric compounds, whereas starch is a polymeric carbohydrate.
Carbohydrates are biomolecules that contain carbon, hydrogen, and oxygen atoms with a 2:1 ratio between hydrogen and oxygen atoms. Starch is a type of carbohydrate.
CONTENTS
1. Overview and Key Difference
2. What are Carbohydrates
3. What is Starch
4. Carbohydrates vs Starch in Tabular Form
5. Summary – Carbohydrates vs Starch
What are Carbohydrates?
Carbohydrates are biomolecules that contain carbon, hydrogen, and oxygen atoms with a 2:1 ratio between hydrogen and oxygen atoms. The empirical formula for carbohydrates is Cm(H2O)n. However, not all carbohydrates fit in this chemical formula, e.g. uronic acid, fucose, and not all compounds having this type of chemical formula are carbohydrates, e.g. formaldehyde, acetic acid, etc.
The term carbohydrate is a synonym for saccharide. Carbohydrates include sugars, starch, and cellulose. We can divide carbohydrates into four groups as monosaccharides, disaccharides, oligosaccharides, and polysaccharides. Among these four types, monosaccharides and disaccharides are the smallest carbohydrates having a low molecular weight. Commonly, these compounds are known as sugars.
There are many food sources for carbohydrates, including natural and processed foods. For example, carbohydrates are abundant in flour, bread, cereal, potatoes, table sugar, lactose in milk, honey, jam, biscuits, and many other sweet foods.
Important roles of carbohydrates in living organisms include polysaccharides being used as energy storage components, as structural components, as components in coenzymes such as ATP, in fertilization, as components in the immune system, in blood clotting, etc.
Furthermore, carbohydrate chemistry is an important and complicated branch of chemistry. Some major organic chemical reactions in which carbohydrates take part include Amadori rearrangement, carbohydrate digestion, Nef reaction, Wohl degradation, cyanohydrin reaction, carbohydrate acetalization, etc.
What is Starch?
Starch is a type of carbohydrate that falls under the group of polysaccharides. It is also named as amylum. This material contains numerous glucose units linked to each other through glycosidic bonds. Most green plants produce this polymeric carbohydrate for energy storage. We can observe that this is the most common carbohydrate in human diets, and there is a large amount of starch in staple food such as wheat, potatoes, maize, rice, and cassava.
Starch is a white, tasteless, and odorless material. It appears as a powder. This starch powder is insoluble in cold water and alcohol. There are two types of components in starch as a linear component or helical amylose and branched amylopectin. The amount of amylose and amylopectin typically depends on the plant species; however, this can range from 20 to 25% of amylose, and the amylopectin amount ranges from 75 to 80%.
In addition to storing energy in food, starch is also important in some non-food applications, which include papermaking, manufacture of corrugated board adhesives, as clothing starch, production of bioplastic, production of gypsum in the construction industry, etc.
What is the Difference Between Carbohydrates and Starch?
Carbohydrates are important biomolecules. Starch is a type of carbohydrate. The key difference between carbohydrates and starch is that carbohydrates can be polymeric or non-polymeric compounds, whereas starch is a polymeric carbohydrate.
The below infographic presents the differences between carbohydrates and starch in tabular form for side by side comparison.
Summary – Carbohydrates vs Starch
Carbohydrates are biomolecules that contain carbon, hydrogen, and oxygen atoms with a 2:1 ratio between hydrogen and oxygen atoms. Starch is a type of carbohydrate that comes under the group of polysaccharides. The key difference between carbohydrates and starch is that carbohydrates can be polymeric or non-polymeric compounds, whereas starch is a polymeric carbohydrate.
Reference:
1. “What is Starch.” Study.com | Take Online Courses. Earn College Credit. Research Schools, Degrees & Careers.
Image Courtesy:
1. “Grain Products” By Scott Bauer – United States Department of Agriculture (Public Domain) via Commons Wikimedia
2. “Rice-starch-pack-shot” By Frisket – Own work (CC BY-SA 4.0) via Commons Wikimedia