BIO 207C 1st EditionLecture 2Chapter 3Prokaryotic Profiles: The Bacteria and ArchaeaProkaryotic Form and FunctionI. Prokaryotes differ from Eukaryotes by:a. The way their DNA is packaged (lack of nucleus)b. Makeup of their cell wall (peptidoglycan)c. Their internal structures (lack organelles)Prokaryotic Shapes and ArrangementsI. Most are unicellularII. Some can act as a group, creating biofilmsIII. Basic shapes include:a. Several types of arrangements-prefix describes themi. Diplo- twoii. Strepto- in chainsiii. Staphylo- in clusters (coccus only)External StructuresI. Flagellar Arrangementsa. Can be used for identification purposesi. Monotrichousii. Peritrichousiii. Lophotrichousiv. AmphitrichousBacterial MovementI. Move in response to chemical signalsa. Molecules bind to receptors on the cell triggering the flagellum to rotatei. 2 types of movement1. Runs2. TumblesExternal StructuresI. Fimbriaea. Used for attachmentII. Pilia. Used for attachment and transfer of genetic material during conjugationIII. Glycocalyxa. Composed of carbohydrates, proteins, or bothb. Protects against dehydration, phagocytosisc. Used for adhesion (in formation of biofilms)IV. Capsulea. Bound more tightly to the cell than the glycocalyxb. Enhances the pathogenicity of bacteriaV. Cell Envelopea. Cell wallb. Plasma Membranec. Outer membraneVI. Cell Walla. Mainly composed of peptidoglycanb. Possessed by most bacteriac. Gives shape and strength to the cell (enables it to withstand osmotic pressure)d. 2 types:i. Gram positive cell wall1. Has a thick layer of peptidoglycan2. Contains proteins which can act as toxins 3. Gram stains deep purple4. Target of some antibiotics-penicillinii. Gram negative cell wall1. Thin layer of peptidoglycan2. Has an outer membrane3. Acts as endotoxin-causes shock and fever and may lead to organ damage and death4. Acts as barrier to certain antibiotics making these infections harder to treat5. Gram stains pinkVII. Plasma membranea. Composed of phospholipid bilayer interspersed with proteinsb. Functions to:i. Provide a site for metabolic reactionsii. Transport substances into and out of the cellInternal StructuresI. Cytoplasma. Mostly composed of waterb. Contains soluble proteins, salts, carbohydratesc. Site of nearly all chemical reactions in the celld. Contains the DNA in the nucleoidII. Nucleoida. Contains the bacterial chromosomeb. Also contains plasmidsi. Pieces of DNA separate from chromosomeii. May code for toxin production, antibiotic resistanceiii. Able to replicate and be passed on to next generation of cells and shared with other bacteriaIII. Ribosomesa. Composed of RNA and proteinb. Functions in protein synthesisIV. Inclusion bodiesa. Used for storagei. Metachromatic granules- phosphateii. Magnetosomes- magnetiteV. Cytoskeletona. Composed of actin and tubulinb. Help determine cell shapec. Function in cell divisionVI. Endosporesa. Structures formed in response to harsh environmental conditionsb. Allow the bacteria to be dormantc. Composed of dipicolinic acid and calciumd. When environmental conditions are again favorable, endospores will germinate and become bacterial