BI111 Lecture Notes - Lecture 4: Fluid Mosaic Model, Gram-Negative Bacteria, Spiral Bacteria
Document Summary
Bacteria can be rod shaped or circular shaped. Polar head groups associate with water but hydrophobic tails associate with each other to avoid water. When placed in water phospholipids associate spontaneously side by side and tail to tail to form membranes. O2, co2, h2o, lipid substances can pass through. Proteins can be inner, outer (peripheral) and transmembrane (integral) Animal cells do not have a cell wall outside the cell membrane. So do most prokaryotic cell providing structural support and influencing shape of cell. Division of the eubacteria: gram negative and gram positive. Gram positives have a thick peptidoglycan layer in cell wall. Gram negatives have a thin peptidoglycan layer and an outer membrane. Teichoic acids: in the cell wall of gram positive bacteria and extend to the surface of the peptidoglycan layer. Some degree of resistance to diffusion of molecules. Composed of polysaccharide chains, with short chains of amino acids: peptido and.
