A student carrying out cell fractionation of plant tissue forgot to label her tubes. The contents of one tube when studied showed organelles bounded by single membrane with acidic internal components. These organelles could be:
Lysosomes
Lysosomes are spherical vesicles containing hydrolytic enzymes capable of breaking down virtually all kinds of biomolecules, including proteins, nucleic acids, carbohydrates, lipids and cellular debris. They are known to contain more than 50 different enzymes, which are all optimally active at an acidic environment of about pH 4.5.