Carbohydrates and Lipids

Which of the following best describes carbohydrates?

• Only simple sugars

• polymers of amino acids

• sugars and polymers of sugars

• fats and oils

What are monosaccharides?

What is the molecular formula for glucose, the most common monosaccharide?

• C5H10O5

• C6H12O6

• C12H22O11

• CH2O

Which of the following is a six-carbon sugar (hexose) that serves as an energy source for organisms?

• Glyceraldehyde

• Ribose

• Glucose

• Sucrose

What is a disaccharide?

• Three monosaccharides joined by a glycosidic linkage

• A sugar with six carbon atoms

• Two monosaccharides joined by a glycosidic linkage

• A sugar with a ring structure

Compare the number of carbons in glucose and fructose. What do they have in common?

• Both have three carbons

• Both have five carbons

• Both have six carbons

• Both have seven carbons

What is the main function of starch in plants?

• To provide structural support to the cell wall

• To store sugars as a polymer of glucose monomers

• To transport water throughout the plant

• To synthesize proteins

How do animals store sugars for later use?

• As cellulose in the cell wall

• As starch in plastids

• As glycogen in muscle tissue

• As sucrose in the blood

What is the difference between starch and cellulose?

Why can starch be used as an energy reserve in plants?

• Because it is insoluble in water

• Because it can be hydrolyzed to release glucose

• Because it forms strong fibers for support

• Because it can be stored within the cell wall