BSC-2010 Lecture Notes - Lecture 4: Cell Membrane, Nuclear Membrane, Lipid Bilayer
Document Summary
Cells: simplest collection of matter that can be alive, all are related to their descent from earlier cells, can differ substantially from one another but share common features. Cell fractionation takes cells apart and separates the major organelles from one another. Centrifuges fractionate cells into their component parts. Cf enables scientists to determine the functions of organelles. Prokaryotic: bacteria and archaea are prokaryotic cells, no nucleus, dna in an unbound region called the nucleoid, no membrane bound organelles, cytoplasm bound by the plasma membrane. Basic features of all cells: plasma membrane, semifluid substance called cytosol, chromosomes (carry genes, ribosomes (make proteins) The plasma membrane is a selective barrier that allows sufficient passage of oxygen, nutrients, and waste to service the volume of every cell. The nucleus contains most of the cell"s genes and is usually the most. The nuclear envelope encloses the nucleus, separating it from the: double layer of phospholipids conspicuous organelle cytoplasm.