Monera Flashcards
In the phylogenetic flow chart, eukarya and archae branch off from a common point, what ties eukaryotes to archaebacteria?
Both have introns in their gene sequence.
What makes archae special? Why? How?
They survive in the harshest of conditions like marshes, hot springs, extremely salty areas all owing to their special modifications in the cell structure.
1) . Their cell membrane has branched monolayer chains (PHYTANYL SIDE CHAINS) of lipids instead of the usual unbranched bilayered ones, and this modification decreases the membrane fluidity.
2) . Instead of murein (peptidoglycan: N-acetylmuramic acid and N-Acetylglucosamine), archaebacteria have pseudomurein (N-acetyltalosminuronic acid)
Methanobacterium and methanococcus show what type of nutrition and they convert which substrates into methane?
They are chemoautotrophs and they convert CO₂ , CH₃OH and HCOOH into methane.
~carbon dioxide, methanol, formic acid.
Halobacterium and Halococcus have a pigment which harnesses the sun’s energy and ATP is produced, why then are they considered HETEROTROPHS?
Halophiles do develop a pigmented membrane (purple: bacteriorhodopsin) when exposed to extreme sunlight and ATP is indeed produced but it isn’t able to utilise this ATP for food production and is hence considered as a heterotroph.
Hot water springs? Give reasons for the status quo pH
Temp as high as 80℃ and pH as low as 2
Home to Thermoplasma and Thermoproteus like organisms, hot springs become highly acidic due to production of sulphuric acid by these thermoacidophiles. They oxidise sulphur to sulphuric acid in aerobic conditions and to H₂S in anaerobic conditions and use the energy released for the synthesis of organic food (Hence chemosynthetic in nature).
1) . The growth of Bacillus subtilis is slower than that of Clostridium botulinum. True/False.
2) . Most photosynthetic bacteria are anaerobes. T/F. Give example.
3) . Give one example of decorative anaerobe
False. Vice versa.
1) . Clostridium is an obligate anaerobes whereas Bacillus subtilis is an obligate aerobe. Aerobic respiration releases far more energy than anaerobic.
2) . True. But they are facultative aerobes, can utilise oxygen as well. Eg. CHLOROBIUM
3) . Pseudomonas is a FACULTATIVE ANAEROBE.
Pseudomonas, give classification wrt respiration.
Magical creatures really, usually need oxygen but can survive without it as well hence, Facultative anaerobes
1) . Only kingdom which can synthesise food by harnessing chemical energy. Any other means?
2) . What are the bases of classification used for bacteria wrt nutrition?
3) . Why is bacterial photosynthesis anoxygenic?
1) . Monera is the sole kingdom to show chemoautotrophic nutrition in whittaker’s system. It actually shows both auto (photo and chemo) and hetero (parasitic and saprophytic) nutrition, which is why it is said to show the most extensive nutritional diversity.
2) . Bacteria is placed in a particular nutritional class based on 3 parameters, their primary source of carbon, energy and electron.
3) . In any type of photosynthesis, we need an electron source which could act as reducing power to convert CO₂ into glucose. When H₂O is used as the source of electron, then oxygen is liberated (when water is split). This is seen in Eubacteria (Cyanobacteria) and higher plants. In bacterial photosynthesis, however, water isn’t used as an electron source and hence, oxygen isn’t liberated.
Answer wrt the following: Chlorobium, Thiospirillum, Rhodospirillum, Chromatium, Chloronema, Chloroflexus.
1) . In which of the following are pigments Bacteriochlorophyll (bacteriopurpurin) and bacterioviridin present? What does it imply? Which in which?
2) . Classify on the basis of whether the electron/proton and carbon source is organic/inorganic. Also specify what source.
3) . All of the photosynthetic bacteria are anaerobes.
1). All have either of the above-mentioned pigments which suggests that they have the ability to harness solar energy for the ATP production which can be used to produce food (glucose formed from CO₂, reduction process aided by ATP.)
HOW?
For bacteria: Hydrogen released by the proton sources, (be it inorganic compounds like H₂S or non-sulphur aliphatic organic compounds), is picked up by NAD⁺ which gets reduced to NADH₂. This NADH₂ along with ATP (produced either by trapping light energy or using chemical energy) act as reducing power and convert CO₂ into glucose.
(in higher plants, NADH⁺ picks up the hydrogen)
2). Electron/Proton source: Sulphur or non sulphur
Organic source: used by PHOTOORGANO HETEROTROPHS ~ non-sulphur organic aliphatic
Photosynthesis is redox reaction?
Photosynthesistransfers electrons from water to energy-poor CO2molecules, forming energy-rich sugar molecules. This electron transfer is an example of anoxidation-reductionprocess: the water isoxidized(loses electrons) and the CO2isreduced(gains electrons).
