Understanding Eukaryotic Cells: The Cytoskeleton and Energy Related Organelles

Two of the most essential parts of eukaryotic cell are energy-related organelles and the cytoskeleton. They both play unique and very important roles for the cells of different organisms. As the name suggests, energy-related organelles are responsible for giving an organism energy. The cytoskeleton is responsible for helping the cell maintain its shape.

In plants, the energy related organelles that are essential our chloroplasts. The function of these chloroplasts is to use energy from the sun in order to create carbohydrates, or energy for the plant. They have a three membrane system. They have a double membrane that encloses the stroma in another membrane that is formed by thylakoids. The thylakoid membrane is what actually contains the pigments is able to capture this solar energy. Chloroplasts originated through endosymbiosis.

Another type of energy related organelles are mitochondria. Mitochondria are found in both plants and animals and their main function is to break down carbohydrates and produce ATP. They are very small and are usually only able to be seen under an electron microscope. They have a folded shape on their inner membrane in order to increase surface area. Additionally, the membrane encloses a matrix, which is a mixture of enzymes that help break down carbohydrates and permit the creation of ATP. Additionally, mitochondria help with cellular respiration. In order to properly function, they need oxygen and in turn, they produce carbon dioxide.

The cytoskeleton in eukaryotic cell is what helps maintain the cell shape. They are a network of interconnected proteins and tubules. It extends all the way from the nucleus to the plasma membrane. Additionally, it helps allow cells in the organelles within them to move. Microtubules are small hollow cylinders that are part of the cytoskeleton to help maintain the cell shape and also act as pathways. The protein filaments have a rope like assembly and connect the nuclear envelope to the plasma membrane.

There also motor proteins, which help cells move. Myosin help cells move and assists with muscle contraction. Kinesin and dynein are what move along the microtubules and help transport things from the Golgi apparatus to wherever they are supposed to go based on function. Cilia and flagella help with movement of the cell or with fluids pass the cell. In structure, the cilia are much more abundant than the flagella and are much shorter. However, they both play very important roles for eukaryotic cells.

Source:
Benitz, Bill. Lecture: Biology. October 7, 2009