Cell Organelles Functions

CELL ORGANELLES FUNCTIONS 1. Plasma membrane- It regulates what enters and leaves the cell (also called selective permeability). It also gives the cell shape and protection. 2. Mitochondria- are responsible for energy production. They are also the responsible location of which respiration takes place. 3.Smooth ER- synthesizes and transports lipids and steroids. Some kinds of smooth E.R. accepts, modifies, and transports proteins from the rough E.R. and still other kinds break down energy rich glycogen and fats. 4. Rough ER- Primarily concerned with protein synthesis and transport. Most highly developed in protein exporting cells (eg. liver and pancreatic cells) 5. Ribosome- Ribosomes are the sites of protein synthesis, where RNA is translated into protein. When cells need large numbers of proteins, they must first build numerous ribosomes. 6. Golgi Apparatus- Proteins exported from the rough and smooth E.R. are modified and enclosed in secretory or lysosomal vesicles and transported out of the cell. 7. Vesicles- Contain products that have been packaged/modified by the golgi. (eg. proteins like enzymes, plasma proteins, peptide hormones etc.) It has the same structure as a vacuole only it is smaller in size. Structure W in the first diagram and structure Z in the second, show vesicles. 8. Lysosomes- digests and disposes of foreign particles, malfunctioning structures, and worn out organelles. 9. Vacuoles- In plants it can act as a storage area for ions, metabolic products such as sugars and amino acids, and toxic compounds. Its main function however is to increase cell size and surface area so that the absorption of ions is enhanced. 10. Peroxisomes- Peroxisomes originally were defined as organelles that carry out oxidation reactions leading to the production of hydrogen peroxide. 11. Nuclear envelope- serve as the pathways for the exchange of the materials between the nucleus and the cytoplasm. 12. Nucleus- acts to control the metabolic activities of the cell. Is the central control centre which monitors internal and external conditions and turns on or off different genetic programs. 13. Nucleolus- Rich in RNA and is the site of the synthesis of ribosomes 14. Chromosomes- Carries the genetic code which determines characteristics of an organism. 15. Microtubules- participate in intracellular transport process. 16. Centrioles- The centrioles are a pair of structures composed of microtubules. The primary function of centrioles is to generate the cell's cytoskeleton.