Question

animals also make polysaccharides. excess sugar in animals is stored as glycogen, which is sometimes called animal starch. each large glycogen molecule is formed by many glucose monomers linked together. these long chains of glucose form many branches.
diagram of glycogen structure and highly-branched glycogen
glycogen plays an important role in regulating blood sugar. when glucose levels in blood are low, glycogen is broken down by the body to provide glucose. in the muscles, glycogen is also broken down to release energy to help with muscle contraction.
what are the functions of glycogen? select all that apply.

• energy from glycogen can be used for muscle contraction.
• glycogen provides structural support for cell walls.
• animals store excess sugar as glycogen.
• glycogen can be broken down to release glucose and increase blood sugar.

Explanation:

1. Analyze "Energy from glycogen can be used for muscle contraction": The text says "In the muscles, glycogen is also broken down to release energy to help with muscle contraction." So this is correct.
2. Analyze "Glycogen provides structural support for cell walls": Cell walls are in plants (made of cellulose), and glycogen is an animal polysaccharide for storage/energy, not structural support for cell walls. So this is incorrect.
3. Analyze "Animals store excess sugar as glycogen": The text states "Excess sugar in animals is stored as glycogen". So this is correct.
4. Analyze "Glycogen can be broken down to release glucose and increase blood sugar": The text says "When glucose levels in blood are low, glycogen is broken down by the body to provide glucose" (which would increase blood sugar). So this is correct.

Answer:

• Energy from glycogen can be used for muscle contraction.
• Animals store excess sugar as glycogen.
• Glycogen can be broken down to release glucose and increase blood sugar.