BSC 1005 Lecture Notes - Lecture 4: Lipid Bilayer, Nanometre, Cell Junction
Document Summary
Organelles, endomembrane system, cytoskeleton, cell wall, plastids, cell junctions. The smallest unit that still retains the characteristics of life. All organisms are composed of one or more cells. Frog egg 3mm, plant cell 1-100 micrometers, bacterium 1-5 micrometers, virus 200-300. There are two major types of cells distinguished by their internal organization: nanometers. There is no separation between their dna and the rest of the cell. Dna is coiled into a nucleoid region. Membrane bound structures with a specific function. The dna is organized and contained within the nucleus. Phospholipid layer has hydrophilic head & hydrophilic tails. The most conspicuous organelle that houses the cell"s dna. Instructions for building proteins are contained in dna. Nucleoli (sing = nucleolus) containing rna and proteins. Dna and associated proteins in the form of chromatin (46 threads in most human cells) Nuclear matrix- viscous fluid inside the nucleus. Nuclear envelope- membrane that surrounds the nucleus: 2 membranes.
