4.6.1 Study Notes Vacuoles and Vesicles 

• vesicles are membrane-bounded vesicles that contain specific enzymes

A. Peroxisomes

• • production of hydrogen peroxide (H₂O₂)

  • in the liver peroxisomes help to produce bile salts from cholesterol and also break down fats

  • germinating seeds where peroxisomes convert oils into sugars used as nutrients by the growing plant

  • broken down to water and oxygen by the enzyme catalase

B. Vacuoles

• membranous sacs and are larger than vesicles

• Contractile vacuoles 

  • rid the cell of excess water in protists

• Digestive vacuoles 

  • digest nutrients

• Vacuoles generally store substances

  • e.g., plant vacuoles contain water, sugars, salts, pigments, and toxic molecules

  • central vacuole of a plant cell maintains turgor pressure within the cell, stores nutrients and wastes, and degrades organelles as the cell ages