Question

Organelles can be separated from cell homogenate through

• A. chromatography
• B. X-rays diffraction
• C. differential centrifugation
• D. auto-radiography.

Answer 1

The Correct Option is C

The question asks about the method used to separate organelles from a cell homogenate. The correct answer is differential centrifugation.

Explanation:

Organelles can be separated from a cell homogenate using a technique called differential centrifugation. This process involves centrifuging the cell homogenate at various speeds to separate organelles based on their size and density. Here's how it works:

1. Initial Homogenization: Cells are first homogenized to break them open and release their contents, resulting in a cell homogenate.
2. Centrifugation Steps: The homogenate is subjected to a series of increasing centrifugation speeds:
   • At low speeds, large organelles like nuclei sediment first.
   • At medium speeds, organelles like mitochondria and lysosomes sediment.
   • At higher speeds, smaller components like microsomes (endoplasmic reticulum fragments) sediment.
3. Pellet and Supernatant Separation: After each centrifugation step, the pellet (sedimented organelles) is collected, and the remaining supernatant is subjected to further centrifugation.

Why Other Options are Incorrect:

• Chromatography: This technique is used for separating molecules based on their chemical properties, not for separating organelles.
• X-ray diffraction: This method is used to study crystal structures, mainly of proteins or other molecules, not for separating cellular components.
• Autoradiography: This technique is used to visualize radioactive molecules within cells or tissues and does not separate organelles.

Thus, the technique differential centrifugation is the appropriate method for separating organelles from cell homogenates.