Carbohydrates

Letter 'D' before the name of monosaccharide reveals that the OH group at the second carbon atom is towards the right ie, it only shows the configuration a particular chiral carbon.

The -link ( -glycosidic link) in carbohydrates refers to the specific linkage between the monomer units of glucose in starch, which is found in amylose and amylopectin. Both amylose and amylopectin, which are components of starch, exhibit -glycosidic bonds. - Amylose is a linear polysaccharide with -1,4-glycosidic bonds between glucose units. - Amylopectin, which is a branched polysaccharide, has both -1,4-glycosidic bonds and -1,6-glycosidic bonds. Thus, the correct examples are amylose and amylopectin. Thus, the correct answer is:

Step 1: Analyzing Statement I.
Reducing sugars are carbohydrates that can act as reducing agents because they have a free aldehyde group or a free ketone group. All monosaccharides (like glucose, fructose, galactose) exist in equilibrium with their open-chain forms, which contain either an aldehyde group (aldoses) or a ketone group that can isomerize to an aldehyde (ketoses). This free carbonyl group allows them to be oxidized by mild oxidizing agents like Tollens' reagent or Fehling's solution. Therefore, all monosaccharides are reducing sugars. Statement I is correct.
Step 2: Analyzing Statement II.
Sucrose is a disaccharide made up of two monosaccharide units: -glucose and -fructose. The glycosidic bond in sucrose is formed between the anomeric carbon of glucose (C1) and the anomeric carbon of fructose (C2). These anomeric carbons contain the potentially free aldehyde and ketone groups, respectively. Since both are involved in the glycosidic linkage, neither unit can open up to form a free carbonyl group. Therefore, sucrose does not have reducing properties. The reaction with ammoniacal silver nitrate solution is the Tollens' test, which is a test for reducing sugars. Since sucrose is a non-reducing sugar, it will not give a positive Tollens' test, meaning it cannot reduce the solution. Statement II is incorrect.
Step 3: Final Answer.
Statement I is correct, and Statement II is incorrect.