LS-MCRB 121 1st EditionExam # 1 Study Guide Lectures: 1-7Lecture 1 (January 20)The Microbial World- Prokaryotes and Eukaryoteso Prokaryotes One circular chromosome, not in a membrane No histones No organelles Peptidoglycan cell walls in Bacteria and Pseudomurein cell walls in Archaea Binary Fissiono Eukaryotes Paired chromosomes in a nuclear membrane Histones Organelles Polysaccharide cell walls Mitotic spindle- Prokaryoteso Shapes Most bacteria are monomorphic, some are pleomorphic Bacillus: rods Cocci: spheres Spiral- Spirillum- Vibrio- Spirochete Unusually shaped: star-shaped and rectangularo Arrangements Diplo: pairs Staphylo: clusters Strepto: chainso Glycocalyx Outside cell wall Usually sticky Three layers:- Slime layer: unorganized and loosely attached to cell wall- Biofilm: composed of extracellular polymeric substance (EPS)- Capsule: neatly organized glycocalyx attached to cell wallo Extracellular polysaccharide allows cell to attacho Prevent phagocytosiso Motile Cells Rotate flagella to run or tumble Move toward or away from stimuli Flagella proteins are H antigenso Flagella Outside cell wall Made of chains of flagellin Attached to a protein hook Anchored to the wall and membrane by the basal bodyo Axial Filaments (Endoflagella) In spirochetes Anchored at one end of a cell Rotation causes cell to moveo Fibriae: allow attachmento Pili Usually longer than fimbriae 1-2/cell Facilitate movement Conjugation through sex pilio Cell Wall Prevents osmotic lysis Made of peptidoglycan in bacteriao Peptidoglycan Polymer of disaccharide: NAGS and NAMS Gram-Positive:- Linked by polypeptides- Teichoic acidso Lipoteichoic acids: linked to plasma membraneo Wall teichoic acid: links to peptidoglycan- May regulate movement of cations- Polysaccharides provide antigenic variation- Thick peptidoglycan- 2-ring basal body- Disrupted by lysozyme Gram-Negative:- Lipopolysaccharides, lipoproteins, phospholipids forms the periplasm between the outer membrane and the plasma membrane- Protection from phagocytes, complement, and antibiotics- O polysaccharide: antigen- Lipid A: endotoxin- Porins: proteins that form channels through membrane- Thin peptidoglycan- 4-ring basal body- Endotoxin- Tetracycline sensitiveo Gram Stain Created by Hans Gram Classifies bacteria into gram-positive (penicillin sensitive) or gram-negative (more resistant to antibiotics Process- Primary stain: crystal violet with iodine- Decolorization- Counterstain: safranino Acid-Fast Stains Resist decolorization with acid alcohol A waxy cell wall composed of mycolic acids Mycobacterium and Nocardia Stain using carbolfuchsin which is a lipid soluble stain and can degeneratethe cell wallo Atypical Cell walls Mycoplasmas- Lack cell walls- Sterols in plasma membrane Archaea- Wall- less or of pseudomureino Damage to Cell wall Penicillin inhibits peptide bridges in peptidoglycan- L forms: wall-less cells that swell into irregular shapes and can occur naturally or as a result of penicillin treatment Lysozyme digests disaccharide in peptidoglycan- Protoplast: wall-less cell- Spheroplast: wall-less gram-negative cello Plasma Membrane Phospholipid bilayer Peripheral proteins Integral proteins Transmembrane Proteins Fluid Mosaic Model- Membrane is viscous- Proteins move to function- Phospholipids rotate and move laterally Selective permeabilityo Movement across Membranes Simple diffusion Facilitated diffusion Osmosis Osmotic pressure Active transport Group translocationo Organelles needed to know Cytoplasm Nucleoid Ribosomeso Inclusions and what they doo What are endospores? A dormant form of the bacterium that allows it to survive unfavorable and harsh environmental conditions Resistant to heat, dessication, chemicals, and radiation Bacillus and ClostridiumLecture 2: January 27Cellular Respiration- Oxidation of molecules liberates electrons for an electron transport chain- ATP is generated by oxidative phosphorylation- Intermediate Step:o Pyruvic acid is oxidized and decarboxylated- The Electron Transport Chaino A series of carrier molecules that are oxidized and reduced as electrons are passed down the chaino Chemiosmosis: Energy released can be used to produce ATP- Aerobic respiration: the final electron acceptor in the electron transport chain is molecular oxygen- Anaerobic respiration: the final electron acceptor in the electron transport chain is not oxygenCarbohydrate Catabolism- Energy produced from complete oxidation of one glucose using aerobic respirationFermentation- General definition versus scientific definitiono Releases energy from oxidation of organic moleculeso Doesn’t require oxygeno Don’t use the Krebs cycle or ETCo Uses an organic molecule as the final electron acceptor- Alcohol fermentation: produces ethanol + CO2- Lactic acid fermentation: produces lactic acido Homolactic fermentation: produces lactic acid onlyo Heterolactic fermentation: produces lactic acid and other compounds- Amphibolic pathways: metabolic pathways that have both catabolic and anabolic functionsLecture 3: (Feb 3)Catabolic and Anabolic Reactions- Metabolism: the sum of the chemical reactions of in an organism- Catabolism: provides energy and building blocks for anabolism- Anabolism: uses energy and building blocks to build large molecules- Metabolic pathway: a sequence of enzymatically catalyzed chemical reactions in a cello Determined by enzymeso Enzymes are encoded by genes- Collision Theory: The active site can lower an activation energy barrier by:o Orienting substrates correctlyo Straining substrate bondso Providing a favorable microenvironmento Covalently bonding to the substrate- Enzyme componentso Biological catalysts: specific for a chemical reaction; not used up in that reactiono Apoenzyme: proteino Cofactor: nonprotein componento Coenzyme: organic cofactoro Holoenzyme: apoenzyme plus cofactor- Important Coenzymeso NAD+o NADP+o FADo Coenzyme A- Enzyme Classificationo Oxidoreductase: oxidation-reduction reactionso Transferase: transfer functional groupso Hydrolase: hydrolysiso Lyase: removal of atoms without hydrolysiso Isomerase: rearrangement of atomso Isomerase: rearrangement of atomso Ligase: joining of molecules; uses ATP- Factors Influencing Enzyme Activityo Temperatureo pHo Substrate concentrationo Inhibitors- Generation