Q&A

• Which of the following cannot be digested by humans?

Answer: Cellulose because in humans, the appropriate enzymes to breakdown the beta acetal linkages are lacking.

• Monosaccharides are joined together to make disaccharides by what kind of linkage?

Answer: Glycosidic because disaccharides are formed when two monosaccharides join together by the dehydration synthesis reaction resulting in a glycosidic bond in the two monosaccharide molecules. 

• Galactose is a hexose sugar. Which of the following statements is not correct about galactose?

It will give a negative result with Benedict´s reagent. All the monosaccharides in the Benedict´s has a positive result as they are reducing sugars 

• The branched polymer of glucose which serves as an energy store in humans is called

Answer: Glycogen, It serves as a store of carbon in vertebrates. The energy storage by the liver and muscle tissue

• What colour does iodine solution become in the presence of starch?

Answer: Dark blue, because is not a reducing sugar, it becomes that color in the presence of starch 

• Benedict's reagent is used as a test for reducing sugars. It contains Cu2+ ions. It is therefore what color?

Answer: Blue, the Copper (II) sulfate gives the blue color, is made by anhydrous sodium carbonate and sodium citrate

• Which of the following is NOT a health issue associated with over-consumption of simple carbohydrates?

Answer: Anaemia , because it is caused by a lack of iron in a diet

• Which of the following is a good source of carbohydrate in the diet?

Answer: Rice, because it has a medium glycemic index, also it contains starch 

• Amylose, amylopectin and cellulose are all polysaccharides made of the monosaccharide called

Answer: Glucose , are hydrolysed by enzymes into the glucose monomers used for energy, and are polymers of α glucose and β glucose.