The organelle responsible for the synthesis of proteins in a cell is the ribosome.
The correct answer is the Ribosome. The Ribosome is responsible for protein synthesis in a cell. To find this answer, you can use a biology textbook or reference material that explains the functions of different organelles in a cell. The Ribosome is commonly known to play a vital role in translating genetic information into proteins. It is located either freely in the cytoplasm or attached to the endoplasmic reticulum.