Structure and Function of Biological Macromolecules

AP Biology· difficulty 3/5

Cellulose (beta 1-4) Starch (alpha 1-4) Both polymers contain glucose monomers but differ in glycosidic linkage geometry Humans digest only alpha 1-4 with amylase

Why can humans digest starch but not cellulose, even though both polymers consist of glucose?

  • A

    Starch lacks glycosidic bonds altogether

  • B

    Humans lack enzymes that hydrolyze beta 1-4 linkages of cellulose

    check_circle
  • C

    Starch is a lipid; cellulose is a carbohydrate

  • D

    Cellulose is made of fructose, not glucose

Explanation

Human amylase recognizes alpha 1-4 linkages in starch. The beta 1-4 linkages in cellulose require cellulase, an enzyme humans do not produce.

Want 10 more like this — adaptive to your weak spots?

Related questions