ECE4084 Lecture Notes - Lecture 3: Endoplasmic Reticulum, Nuclear Membrane, Nuclear Lamina
24 Jul 2018
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Document Summary
Compared to prokaryotes, eukaryotic cells are quite different. While both have a plasma membrane, chromosomes, cytosol and ribosomes, eukaryotes have membrane-bound organelles while prokaryotes have no internal membranes. Eukaryotic dna is also bounded by the membranous nuclear envelope, and are significantly larger than prokaryotes. However, their size is limited by their surface area to volume ratio, as many interactions need to occur at the cell membrane to serve the whole cell. Note: the cytoplasm = cytosol + organelles (excluding nucleus). The cytosol is a gel-like substance containing water, ions and proteins, has a ph of around 7 and allows constant movement. The plasma membrane is a selective barrier from the outside of the cell, which allows the passage of oxygen, nutrients and waste across. It is composed of a double layer of phospholipids. The eukaryotic cell also has many internal membranes which partition the cell into organelles. This allows different processes to occur in different environments within the cell.
