Starch is a complex carbohydrate that serves as a primary energy storage compound in plants.
Here's a more detailed explanation:
-
Definition: Starch is a polysaccharide consisting of glucose monomers joined by glycosidic linkages. This essentially means it's a large molecule made up of many smaller glucose (sugar) units linked together.
-
Source: It is naturally produced in the green leaves of plants from excess glucose produced during photosynthesis. Plants store this starch in specialized structures like roots (e.g., potatoes, cassava), stems (e.g., sago), seeds (e.g., wheat, rice, corn), and fruits.
-
Composition: Starch is composed of two main types of glucose polymers:
- Amylose: A linear chain of glucose molecules.
- Amylopectin: A highly branched chain of glucose molecules. The ratio of amylose to amylopectin varies depending on the plant source.
-
Function in Plants: Plants use starch as a way to store energy for later use. When the plant needs energy, it breaks down the starch back into glucose.
-
Function in Human Diet: When humans consume starchy foods, their bodies break down the starch into glucose, which is then used for energy. Starchy foods are a vital part of a balanced diet, providing a sustained release of energy.
-
Examples of Starchy Foods: Common sources include:
- Grains: rice, wheat, corn, oats, barley
- Root Vegetables: potatoes, sweet potatoes, yams, cassava
- Legumes: beans, peas, lentils
-
Industrial Uses: Starch has numerous industrial applications, including:
- Food industry: as a thickener, stabilizer, or adhesive.
- Paper industry: for paper sizing and coating.
- Textile industry: for fabric sizing.
- Adhesive production: in glues and pastes.
In short, starch is a carbohydrate used by plants as an energy storage molecule and consumed by humans as a significant source of dietary energy.
