4.3.1 Study Notes Introducing Eukaryotic

A. Origin of the Eukaryotic cell

• According to the endosymbiotic theory, energy-related organelles, such as mitochondria and chloroplast, arose when a eukaryotic cell engulfed prokaryotic cells 

• Eukaryotic cells are members of the domain Eukarya, which includes the protists, fungi, plants, and animals.

• A membrane-bounded nucleus houses DNA

  • the nucleus may have originated as an invagination of the plasma membrane.

• Eukaryotic cells are much larger than prokaryotic cells

  • have less surface area per volume

B. Structure of Eukaryotic Cells

• Eukaryotic cells are compartmentalized

  • they contain small structures called organelles that perform specific functions. 

    • work together to metabolize, regulate, and conduct life processes

    • endomembrane system communicate with one another

      • each organelle contains its own set of enzymes 

      • produces its own products

      • products move from one organelle to another by transport vesicles

  • the cytoskeleton is a lattice of protein fibers that maintains the shape of the cell and assists in movement of the organelles

• Plant, fungi, and many protist cells contain a cell wall along with a plasma membrane

C. Separating the Contents of Cells 

• Cell fractionation allows the researcher to isolate and individually study the organelles of a cell.

• Differential centrifugation separates the cellular components by size and density.

• Using these two techniques, researchers can obtain pure preparations of any cell component.