3. Cell Walls
Located outside the cell membrane and provides these cells with structural support and protection, and also acts as a filtering mechanism
Major function of the cell wall is to act as a pressure vessel, preventing over-expansion when water enters the cell
They are found in plants, bacteria, fungi, algae, and some archaea. Animals and protozoa do not have cell walls
In plants, the strongest component of the complex cell wall is cellulose, which is a polymer of glucose. In bacteria, peptidoglycan forms the cell wall.
In this diagram, the cell wall is the outer green lining.
4. Ribosomes
are complexes of RNA and protein that are found in all cells
Function
Protein biosythesis, which is the process of decoding RNA into protein
5. Endoplasmic Reticulum
an eukaryotic organelle that forms an interconnected network of tubules, vesicles (small ball of liquid in a cell), and cisternae within cells
Function
protein translation (process in which cells build proteins)
folding and transport of proteins to be used in the cell membrane (e.g. transmembrane receptors and other integral membrane proteins)
production and storage of glycogen, steroids, and other macromolecules
Structure
an extensive membrane network of cisternae (sac-like structures) held together by the cytoskeleton
Rough Endoplasmic Reticulum
studded with ribosome giving it a "rough" appearance
is known as RER
membrane of the RER is continuous with the outer layer of the nuclear envelope
Smoth Endoplasmic Reticulum
synthesis of lipids and steroids, metabolism of carbohydrates, regulation of calcium concentration, drug detoxification, attachment of receptors on cell membrane proteins, and steroid metabolism
6. Golgi Body (Golgi Apparatus)
Structure
composed of membrane-bound stacks known as cisternae
cisternae stack contains five functional regions which are the cis-Golgi network, cis-Golgi, medial-Golgi, trans-Golgi, and trans-Golgi network
each region contains different enzymes which carefully go over the contents depending on where they are supposed to be
Function
main function is to process and package the marcomolecules such as proteins and lipids that are synthesized by the cell
it is a major site of carbohydrate synthesis
7. Lysosomes
organelles that contain digestive enzymes
some biologists say that they are only found in animal cells
sometimes call "suicide-bags" or "suicide-sacs" because of what they do with autolysis which is destruction of a cell through the action of its own enzymes
Functions
the digestion of marcromolecules from phagoctosis (ingestion of other dying cells or larger extracellular material, like foreign invading microbes), endocytosis (where receptor proteins are recycled from the cell surface), and autophagy (wherein old organelles or proteins, or microbes that have invaded the cytoplasm are delivered to the lysosome)
digesting foreign bacteria
