Mic 230 1st Edition Lecture 5 Current Lecture1. Bacteria cell membrane2. Archaea cell membranea. Difference in lipid chemistry i. Uses an ether bond NOT ester to link side chains to glycerol in phospholipids ii. Side chains are hydrocarbons (made up of isoprene units) NOT fatty acidsiii. Some!! Archaea form lipid monolayers NOT bilayers **Difference is in the side chains of the phospholipids…need to be specific**3. Functionsame all 3 domainsvital, break cm, cell diesa. Permeability barrieri. Due to lipid bilayerii. Physical barrier due to hydrophilic/hydrophobic/hydrophilic 1. Charged molecules can NOT cross, regardless of sizeiii. Keeps things out AND in (iv. Membrane is selectively permeable due to proteinsb. Protein anchori. 3000 or so types, many functions, MAJOR function is TRANSPORTii. Transport can be active or passive…there are only so many transporters1. Passive:a. Simple diffusion b. Facilitated diffusion i. Protein helps cross 2. Active transport requires energy a. 3 types of active transporti. Simple transportdriven by proton motive force incell membraneii. Group translocationmodify chemical as brought in typical modification=phosphorylation These notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.iii. ABC systemATP binding cassette c. Energy conservation 4. BACK TO TALKING ABOUT CELL WALL FROM PREVIOUS LECTUREa. Functioni. Provide shapeii. Provides strength 1. Water generally wants in (turgor pressure)iii. A few bacteria without a cell wallMycoplasma, Thermoplasmab. Bacteria 2 types of cell wallsi. Gram negative (stain pink) and gram positive (stain purple) are NOT capitalized 1. Gram positive have a smoother layer while gram negative have a rougher surface and more layers 2. Both have peptidoglycan (PG) ***ONLY FOUND IN BACTERIA*** (small acceptation)a. Amino sugar backbonei. N-acetylglucosamineii. N-acetylmuramic acid ***ONLY FOUND IN BACTERIA*** and easy to test for b. Also have a peptide cross-linkeri. Amino acids (some L and some D…D is less common)ii. 1 of the amino acids has 2 amide groups –NH21. This forms the peptide bond! Involved in the crosslinkinga. Diaminopimelic acid (often in gr-)b. Lysine (often in gr + and often have an interbridge)c. StabilityPG provides strengthi. Things that affect stability1. Lysozyme attacks PG cleaves the backbone 2. Penicillin inhibits cross-linking 3. Gram positive cella. 1 layer of PGthick layer w/lots of cross linkingb. Has teichoic acids (Unique to gr +)c. Some are lipoteichoic acid  can anchor to cell membraneby lipid