Section Summary: Cell Structure

Organelles

• Organelles are structures that carry out different functions within a cell.
• Organelles in a cell are analogous to the organs in a body.
• Organelles are suspended in a water-based fluid called cytosol.

The Nucleus

• The nucleus stores the genetic information (chromosomes) of eukaryotic cells.
• The nucleus is roughly spherical and is surrounded by two membranes.
• The nucleus is the 'brain' of a cell.

The Mitochondrion

• Mitochondria are the power houses of a cell.
• Mitochondria convert biomolecules (i.e. fats and sugars) into energy.
• By-products of energy production in mitochondria may damage DNA and cause mutations.

The Ribosome

• Ribosomes are made up of two large complexes comprised of RNA and protein.
• Ribosomes are located in the cytosol. Their function is to read RNA and produce proteins in a process known as translation.

The Cytoskeleton

• The cytoskeleton is an intricate network of proteins that criss-cross the cytoplasm of a cell.
• Actin and tubulin are the proteins used to build main fibers of the cytoskeleton (microfilaments and microtubules, respectively).
• The cytoskeleton serves several key functions:
  • Provides structure to cells and a place to anchor organelles
  • Cell motility
  • Control of cell division during mitosis
• Changes in the cytoskeleton that allow increased movement are observed in cancer cells.
• Many anti-cancer drugs work by interfering with the activity of cytoskeletal proteins.