Question | Answer |
Poly-B-hydroxy-alkanoate Inclusion | Lipid storage of carbon (energy storage), used when cell does not need the energy, predominant mass of cell, resembles plastic |
Inorganic Molecule Inclusions | Use H2S as energy source by oxidizing it to S0, store sulfur as granules in periplasm, gram -, don't go into cell until needed, purple sulfur bacteria |
Magnetotacitic Bacteria | Orient themselves in a magnetic field, contain magnetosomes (bodies of Fe3O4) |
Gas Vesicles | Made of protein, permeable to gas not water, allows planktonic bacteria to maintain a higher elevation to reach sunlight, made of overlapping gas vesicle proteins, GvpC made of a helices and GvpA beta sheets |
Endospores | Differentiated forms of bacteria that can withstand extremes of heat, chemical, treatment, desiccation, and radiation, form during periods of poor conditions and germinate when favorable conditions arise again |
Spore Coat | Made of proteins, provides most of the endospores chemical resistance |
Cortex | Made of peptidoglycan, between the two membranes, helps with dehydration of the spore core to confer heat resistance and reduce solubility |
Exosporium | Not in all spores, does not provide much protection, shed after maturation |
Core Wall | Between cortex and spore coat, not of significance |
Core of the Cell | Contains tightly packed DNA |
Endospore Forming Groups | Clostridium and Bacillus |
Calcium-dipicolinic Acid | Reduces water availability in spores and intercalates DNA which protects and stabilizes it |
SASPs | Small acid soluble proteins, bind DNA and protect it from the desiccation, make it resistant to UV radiation and compression |
Binary Fission | DNA replication and cell elongation, septum formation, completion of septum with formation of distinct walls, cell separation of symmetrical cells |
Autolysin | Enzyme that forms the septum in dividing cells |
Endospore Formation | DNA becomes more dense, endospore septum grows around protoplast, forespore formation, exosporium appears, primordial cortex is formed between the two membranes, forms resistance factors, lysis of cell and release of endospore |
Binary Fission vs Endospore Formation | Binary fission forms two symmetrical cells while endospore formation forms two asymmetrical cells, both produce a cell with an identical complete genome |
Flagella Motility | Used to describe the movement of microbes through LIQUID, driven by energy derived from the proton motive force |
Gliding Motility | Used to describe the movement of microbes across SOLID surfaces, does not involve flagella |
Taxis | Directed movement of cell in response to something |
Chemotaxis | Movement in response to chemicals |
Phototaxis | Movement in response to light |
Aerotaxis | Gradient dissolved in oxygen |
Osmotaxis | Gradient in salt concentrations |
Twitching Motility | Movement due to pilus |
Detecting Chemotaxis | Capillary tube draws up liquid, test whats in the capillary tube and test how the organisms respond - measuring movement of organisms, attractant draws into tube, repellent pushes away from tube, control equal |
2nd Most Abundant Element in the Cell | Nitrogen (behind carbon) |
Role of Iron in Cellular Metabolism | Important in redox reactions, cytochromes and iron-sulfur proteins, Insoluble form: ferric Soluble form: ferrous |
Sidrophores | Bind to iron on the outside of the cell, hydroxomate and enterobactin (entric bacteria, free floating), aquachelin (hydrophobic tail allows it to be bound to the membrane) |
Culture Media | Defined: concentration known, Complex: concentrations unknown, Selective: growth of desired organisms only, Non-selective, Differential: distinguish between types of microbes |
MacConkey Agar | Contains bile salts and crystal violet to inhibit other bacteria, contains lactose and pH indicator to differentiate lactose fermenters |
Eosin-Methylene Blue Agar | Contains Eosin Y (inhibits G+) and methylene blue, as well as lactose, E. coli forms a metallic sheen due to high lactose fermentation |
Free Energy | The energy released from a reaction that can be used to do work |
Endergonic | Reaction requires energy, not favorable, DG0' is positive |
Exergonic | Reaction releases energy, favorable, DG0' is negative |
Free Energy of Formation | Energy required for the formation of a compound from its elements (products - reactants), 0 for elements |
DG0 vs DG0' | DG0: change in free energy under actual conditions
DG0': change in free energy under standard conditions |
Activation Energy | Energy required to bring all molecules in a chemical reaction into the reactive state |
Enzymes | Catalytic proteins that speed up the rate of biochemical reactions by lowering activation energy, highly specific, do not change bioenergetics of reaction |
Active Site | Site on enzyme where substrate binds, affects catalysis |
Prosthetic Group | Non-peptide, enzyme-associated molecule that is tightly bound as part of the enzyme complex |
Coenzymes | Non-peptide, enzyme-associated molecule that is loosely bound to enzyme complex, may associate with several different enzymes, derived from vitamins |
Reduction Potential of Half Reaction | Tendency of a compound to accept or donate electrons (E0')
More negative reduction potential = more likely electrons will be given up |
Redox Reaction | Oxidized looses electrons = electron donor
Reduced gains electrons = electron acceptor
Want positive reduction potential for spontaneous favorable reaction
Donor must be higher on chart than acceptor |
NAD+/NADH | Freely diffusible electron carrier, electrons from donor can reduce NAD+ to NADH, NADH donates electrons to oxidize to NAD+
NADH is good electron donor with - E0' |
Most Common Energy Rich Compound | ATP - Energy released by redox reactions is conserved in compounds containing energy rich phosphte or sulfur |
Short/Long Term Energy Conservation Compounds | Short term: phospoenolpyruvate, 1,3-bisphosphoglycerate, Acetyl phosphate, ATP/ADP, Acetyl CoA
Long term: lipids or polysaccharides like glycogen, poly-hydroxyalkanoates, elemental sulfur polymers |
Substrate-level Phosphorylation | Fermentative mechanism in which ATP is synthesized at discrete reaction steps, electron donor is the same as the terminal electron acceptor |
Glycolysis | Glucose 6C forms 2 3C pyruvate which form either ethanol or lactate, net gain of 2ATP, NADH acts as coenzyme and is reduced when pyruvate is reduced to fermentation products |
Fermentation | Only releases a small amount of energy bc the carbon is not completely oxidized and the difference in reduction potential between substrate and products is small |
Terminal Electron Acceptor in Aerobic Respiration | Oxygen |
Electron Transport Carriers | NADH dehydrogenase, flavoproteins, iron-sulfur proteins, cytochromes, quinone |
ETC | Transfer of proteins to outside and accumulation of protons of the outside charges the membrane and creates a proton motive force |
Proton Motive Force | Drives the ATP synthase |
Inhibitors | Block electron transport, preventing establishment of a proton gradient
EX: carbons monoxide and cyanide |
Uncouplers | Allow protons to pass across the membrane (leaky) bypassing the use of ATPase - disrupts coupling of ETC and proton gradient with ATPase
EX: dinitrophenol |
Glycolysis vs CAC | B: creates reduction potential and energy via substrate level phosphorylation and yields intermediates for biosynthesis - 2 vs 38 ATP |
CAC Oxidized and Reduced | NADP to NADPH, GDP to GTP, FAD to FADH, NAD to NADH |
Anaerobic Respiration | Use of any other terminal electron acceptor |
Catabolism | Generates energy by breaking down molecules |
Anabolism | Consumes energy through biosynthesis of sugars, polysaccharides, amino acids, nucleotides, and fatty acids |
Gluconeogenesis | Using intermediates from the citric acid cycle to make glucose |
Purines | Made from inosine |
Pyrimidines | Made from orotate |
Fatty Acid Biosynthesis | Acyl carriere protein ACP holds elongating fatty acids, carbons add 2 at a time from three carbon malonyl-ACP |
Lipids | Formed when fatty acids are added onto glycerol via ester linkages, phytanyl side chains in archaea, 3rd glycerol carbon bound to a polar group |
Growth | Refers to an increase in cell number |
Doubling of a Population | Generation |
Fts Proteins | Filamentous temperature sensitive mutants, fail to divide at high temps, FtsK helps chromosomes segregate to poles, FtsZ polymerizes to form a ring around the division plane, depolymerization enables formation of septum |
Divisome | Complex of proteins formed for cell division |
MinC | Proteins prevent cell division and formation of Z rings until the cell center has been located |
MinD | Same as MinC |
MreB | Forms polymers similar to actin filaments, cell shape
Cocci have no MreB |
Cell Wall Assembly | |
Autolysins | Break glycosidic bonds at point of new synthesis |
Bactoprenol | Hydrophobic lipid that transports precursors of peptidoglycan across membrane, helps with assembly proteins to catalyze incorporation of new sugars |
Peptidoglycan Transpeptidase | Enzyme that catalyzes cross-linking of peptide side chains, target of penicillin |
Pili | Composed of protein, long and few in number, adhesion, twitching motility, conjugation |
Fimbriae | Composed of protein, short and numerous, adhesion |
Capsules | Composed of POLYSACCHARIDE, virulence factors, adhesion and phagocytosis avoidance |
S-layers | Lattice of protein, found instead of cell walls in Archaea |
Oxidative Phosphorylation | Respiratory mechanism in which ATP is synthesized by harnessing the proton motive force |
NADH Dehydrogenase | Protein bound to inside of cytoplasmic membrane, transfer 2 e and 2 p, binds NADH and reduces it to NAD+, e and p transferred to flavoproteins |
Flavoproteins | Flavin portion bound to protein that accepts 2 p and 2 e but only passes on 2 e, reduced but then oxidized when passes on e to next carrier |
Iron-sulfur Proteins | Non-heme iron proteins, only carries electrons |
Cytochromes | Have heme prosthetic groups, with iron center, transfers only single electron, highest reduction potential |
Quinone | Hydrophobic, free to move around, found in membrane, accepts 2 p and 2 e but only passes on 2 e - NOT A PROTEIN |