Carbohydrates：練習題

Maltose is a disaccharide formed by the condensation of two specific monosaccharides. Which pair of molecules reacts to form maltose?

Sucrose is a disaccharide commonly found in plants. Which of the following pairs of monosaccharides are joined together by a condensation reaction to form one molecule of sucrose?

A sample contains a mixture of sucrose and lactose. Which of the following experimental results would be expected after performing a Benedict's test directly on the initial mixture, and then after complete acid hydrolysis followed by neutralization and a second Benedict's test?

A student is carrying out a Benedict's test on an unknown solution. The solution initially gives a negative result. After boiling a fresh sample with dilute hydrochloric acid and then neutralizing it, the Benedict's test gives a brick-red precipitate. Which molecule was likely present?

In the process of producing a dilution series of a glucose solution, a student starts with a \(1.0\text{ mol dm}^{-3}\) stock solution. If the student adds \(2\text{ cm}^{3}\) of stock solution to \(8\text{ cm}^{3}\) of distilled water, what is the final concentration of the new solution?

A student added Benedict's solution to a liquid sample and heated it in a water bath, but the mixture remained blue. After boiling a fresh sample with hydrochloric acid, neutralizing it, and re-heating with Benedict's solution, a brick-red precipitate formed. Name the type of chemical bond that was broken during the boiling with acid.

Maltose and sucrose are both disaccharides. Identify the monosaccharides produced by the hydrolysis of one molecule of sucrose and state the name of the chemical bond that is broken during this reaction.

Describe the structural differences between starch and cellulose in terms of the glucose isomers involved and explain how the 1,4-glycosidic bonds in cellulose lead to the formation of microfibrils.

Starch and cellulose are both polysaccharides found in plant cells.

a) Describe the structural differences between a molecule of starch and a molecule of cellulose. (3 points)
b) Explain how the structure of cellulose is related to its function in plant cell walls. (2 points)