Question

Which cellular organelle would be concentrated at the top of the centrifuged mixture after centrifugation of cells containing solution?

• A. Nuclei
• B. Endoplasmic reticulum
• C. Mitochondria
• D. Ribosomes
• E. Membrane-bound proteins

Answer 1

Answer: (C)

Mitochondria

Centrifugation of cells is a sedimentation process used to separate certain organelles for analysis of specific parts of cells. a sample of tissue is lysed to break the cell membranes and mix up the contents of the cell. However, while the procedures may break many of the membranes of the cell including the plasma membrane and endoplasmic reticulum, it leaves certain organelles such as mitochondria, nuclei, Golgi apparatus, peroxisomes and lysosomes intact in a homogeneous extract. During the process, particles of different densities or size sediment at different rates. The largest and most dense particle sediments first followed by less dense and smaller particles. Hence the cellular organelle concentrated on the top of the centrifuged mixture will be the mitochondria due to its less density and small size. Thus, the correct answer is option C.