nucleus-serves as the information processing and administrative center of the cell;Â stores the cell's hereditary material, or DNA, and it coordinates the cell's activities, which include growth, intermediary metabolism, protein synthesis, and reproduction (cell division) nuclear envelope-double-layered membrane that encloses the contents of the nucleus during most of the cell's life cyclenuclear pores-regulate the passage of molecules between the nucleus and cytoplasm, permitting some to pass through the membrane, but not others chromatin(DNA)-for DNA to function,it is combined with proteins and organized into a precise, compact structure, a dense string-like fiber called chromatin. nucleolus-a membrane-less organelle within the nucleus that manufactures ribosomes, the cell's protein-producing structures
-tiny organelles composed of approximately 60 percent ribosomal RNA (rRNA) and 40 percent protein-not bound by a membrane -ribosomes are mainly found bound to the endoplasmic reticulum and the nuclear envelope, as well as freely scattered throughout the cytoplasm -serve as the protein production machinery for the cell and are consequently most abundant in cells that are active in protein synthesis, such as pancreas and brain cells
-a network of flattened sacs and branching tubules that extends throughout the cytoplasm in plant and animal cells-allows molecules to be selectively transferred between the lumen and the cytoplasm smooth ER-chiefly involved with the production of lipids (fats), building blocks for carbohydrate metabolism, and the detoxification of drugs and poisons rough ER-directly continuous with the nuclear envelope which is also studded with ribosomes
-to processÂ proteins targeted to the plasma membrane,Â lysosomes or endosomes and those that will be formed from the cell, and sort them withinÂ vesicles-basically it functions as a central delivery system for the cell.
-helps maintain cell shape-the internal movement of cell organelles, as well as cell locomotion and muscle fiber contraction could not take place without the cytoskeleton. microtubules-thick, strong spirals of thousands of subunits made of the protein calledÂ tubulin microfilaments-long, thin, and stringy proteins;work with microtubules to form the structure that allows a cell to hold its shape, move itself, and move its organelles intermediate filaments-function as tension-bearing elements to help maintain cell shape and rigidity, and serve to anchor in place several organelles, including the nucleus and desmosomes
-contain hydrolytic enzymes necessary for intracellular digestion-in white blood cells that eat bacteria, lysosome contents are carefully released into the vacuole around the bacteria and serve to kill and digest those bacteria