Radioisotopes are frequently used to label molecules in a cell.The fate of atoms and molecules in a cell can then be followed.Assume Saccharomyces cerevisiae is grown in a nutrient medium containing the radioisotope ³⁵S.After a 48-hour incubation,the ³⁵S would most likely be found in the S.cerevisiae's
A)carbohydrates.
B)nucleic acids.
C)water.
D)lipids.
E)proteins.

Question

Quizplus · Accepted Answer

Radioisotopes are frequently used to study the uptake and distribution of molecules in a cell. In this scenario, the radioisotope ³⁵S is used to label molecules in S. cerevisiae. Sulfur is typically found in amino acid side chains which make up proteins. Therefore, after a 48-hour incubation, the ³⁵S would most likely be found in the proteins of S. cerevisiae. Hence, the correct answer is E) proteins.

Radioisotopes Are Frequently Used to Label Molecules in a Cell