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24 Cards in this Set
- Front
- Back
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What is a bactoprenol? what does it do?
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Bactoprenol is a hydrophobic C55 alcohol which bonds to the Nag/ NAM pentapeptide peptidoglycan precussors in the cytoplasm and renders them sufficiently hydrophobic to be trasfered across the cell membrane.
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What is the role of autolysin?
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Autolysin acts as a lysosome and cutts nicks in the preexisiting peptidoglycan layer for the insertion of new material.
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What do the enzymes transglycosylase do?
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Bactoprenol interacts with the transglycoslase enzymes on the outside of the cell which then catalyzes the creation of the glycosidic bonds bewteen Nag and Nam residues
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What does the bactoprenol attach to?
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It inserts itself into the cytoplasmic membrane
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What is generation time?
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It is the time / the number of generations at time t. The slop of the line gives the growth rate. N =No*2^n
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In an open system the growht and growth yeild are controlled by what?
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Growth is controlled by the dilution rate and growth yeild is controlled by the nutrient concetration. Both are controlled individually and simulstanously.
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List the temperature classes of bacteria and archaea:
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psychrophile, mesophile, thermophile, hyperthermophile, hyper extrem thermophile.
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What is water activity?
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It is a measure of the vapour pressure/ pure water: measure of teh energy status of water in a system. The scal ranges from 0 - 1: 1 at high water concentrations, less then 1 low water concentrations in the presence salt or sucrose.
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What is the general condition that most cells find themselves relative to the solute concentration outside the cell?
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The general scenario experienced by most cells is that their internal cytoplasm is generally has a higher salt concentration then the exeterior = hyperosmotic. The petidoglycan layer prevents the rapid influx of water into the cell = causing it to burst.
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What organisms have evolved to live in low aw's
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Fungi and mould
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What are the characteristics of halophiles, Nonhalophile, Halotolerant, extremehalophile, osmophiles, and xerophiles?
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Halophiles grow best in the presence of salt. The salinity can not be substituted with the use of KCL. Nonhalophiles can not grow in the presence of salt, halotolerant grow best at low aw in the absence of added solutes, extremehalophiles grow best in the presence of high salinities, osmophiles grow in the presence of high sugar concentrations, xerophiles grow in very dry enviroments
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What reaction does the enzyme catalase facilitate?
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The conversion of 2 peroxides to 2 water and oxygen
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What reaction does peroxidase catalze?
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the conversion of peroxide + NADH ( reducing equivalent) to water and oxidized NAD+
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What reaction does superoxide dismutase catalyze?
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2 superoxides + 2H = 1 peroxide and 1 02
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What does the combination of superoxide simutase and catalse do?
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With the use of rubredoxin ( reducing agent) to convert superoxide + 2H = peroxide and rubredoxin oxidized
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What kind of enviroments and microorganisms can superoxide reductase be found?
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Found in organsims that lack the dismutase enzyme - found in obligate aneorobes, archaea , sulphate reducing bacteria and some microaerophiles
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What are genes? Where are located? What is genetic information carried on?
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Genes are the functional unit of genetic information, they are located on chromosomes, and genetic informaiton is carried on nucelic acids ( DNA and RNA)
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List the nitrogen bases in DNa and RNA and thier pairing and bonds
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Pyrimadines: c, T, and U in RNA only; Purine A and G. Base pairing are A-T or A-u RNA = double bond and G-C DNA and RNA triple bond
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What are some other functions of nuleotides>
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ATP and GTP energy sources, function as redox reactons, carriers of sugars in polysaccride synthesis and regulatory molecules
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What direction does DNA polymerase synthesize
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5'-3' always adding at the end of the 3'Oh group
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What is the difference betwenn deoxiribose sugars adn ribose sugars?
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Deoxiribose = DNA ribose sugar - rna has an extra OH
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What are some characteristics of RNA"
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Single stranded, ribose sugars, and substituded uracil base for thymine
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what are the uses of the major and minor grooves found in the double helix structure of DNA?
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Major groove is an area in the double helix where there is plenty of space. Every turn of the helix = 10 bp
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What is an episome?
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plasmids that can integrate into the chromosome their replication is under the control of the chromosome
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