Summary Essential cell biology H1-8 &10: Summary of chapters 1tm8 and 10 of essential cell biology (complete and updated)

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Essential cell biology H1-8 &10 Summary MCB Chapter 1 - In every cell, the information encoded in the DNA is read out, or transcribed, into a chemically related set of polymers called RNA. A su... bset of these RNA molecules is in turn translated into yet another type of polymer called a protein. - If cells are the fundamental units of living matter, then nothing less than a cell is can truly be called living - A bacterium contains no organelles - Mitochondria contain their own DNA and reproduce by dividing in two. Because they resemble bacteria in so many ways, they are thought to have been derived from bacteria that were engulfed by some ancestor of present-day eukaryotic cells - The endoplasmic reticulum is an irregular maze of interconnected spaces enclosed by a membrane. It is the site where most cell-membrane components, as well as materials destined for export from the cell, are made. This organelle is enormously enlarged in cells that are specialized for the secretion of proteins - Stacks of fastened, membrane-enclosed sacs constitute the Golgi apparatus, which modifies and packaged molecules made in the ER that is destined to be either secreted from the cell or transported to another cell compartment. - Lysosomes are small, irregularly shaped organelles in which intracellular digestion occurs, releasing nutrients from ingested food particles and breaking down unwanted molecules for either recycling within the cell or excretion from the cell - Cytosol is the part of the cytoplasm that is not contained within intracellular membranes - In eukaryotic cells, the cytosol is crisscrossed by long, fine filaments. This system of protein filaments, called the cytoskeleton, is composed of three major filament types. - The thinnest of these filaments are the actin filaments, they are abundant in all eukaryotic cells but occur in especially large numbers inside muscle cells, where they serve as a central part of the machinery responsible for muscle contraction. - The thickest filaments in the cytosol are called microtubules because they have the form of minute hollow tubes. In dividing cells they become reorganized into a spectacular array that helps pull the duplicated chromosomes in opposite directions and distribute them equally to the two daughter cells. - Intermediate in thickness is the intermediate filaments, which serve to strengthen the cell. - That single-celled eukaryotes can prey upon and swallow other cells is borne out by the behavior of many of the free-living, actively mobile microorganisms called protozoans [Show More]

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