Properties of Starch:

Starch is a complex carbohydrate that serves as a storage form of energy in plants. It is composed of two main components: amylose and amylopectin. Let's evaluate each statement given and determine which ones are correct.

a) Presence of amylose and amylopectin chains:
This statement is correct. Starch is made up of two types of glucose polymers: amylose and amylopectin. Amylose is a linear chain of glucose molecules connected by alpha-1,4-glycosidic bonds. On the other hand, amylopectin is a branched chain of glucose molecules linked by both alpha-1,4-glycosidic bonds and alpha-1,6-glycosidic bonds. The presence of these two components gives starch its unique structure and properties.

b) Stored food in plants:
This statement is correct. Starch serves as the primary storage form of energy in plants. It is synthesized in the leaves through photosynthesis and then transported to various parts of the plant, such as the roots, stems, and seeds, where it is stored. When the plant requires energy, starch is broken down into glucose units, which are then utilized for metabolic processes.

c) Soluble in water:
This statement is incorrect. Starch is insoluble in cold water. When starch is mixed with water, it forms a suspension, but it does not dissolve. However, starch can form a colloidal solution when heated in water, leading to the thickening or gelatinization of the mixture. This property is often utilized in cooking and food processing to achieve desired textures and consistencies.

d) Not sweet:
This statement is correct. Starch is not sweet. Unlike sugars, which are simple carbohydrates and have a sweet taste, starch is a complex carbohydrate and does not exhibit sweetness. This is why starchy foods like potatoes, rice, and bread do not taste sweet on their own.

In conclusion, the correct statements regarding the properties of starch are:
- Presence of amylose and amylopectin chains.
- Stored food in plants.
- Not sweet.