evoke a sense of wonder Common mples of bio exa ewhe glow in

evoke a sense of wonder Common mples of bio- exa ewhe glow in the dark algal, glow worros, ilyfish, and saxfire capable of world of lie, bieluminescens (light peodacingu organisms organisms include fireflies on a estimated that nearly 90 percewr of exist as well. These bacteria can be found in the marine environment with several species of fish and mollusc as ormelluso provides the bacreria and ooygen and the finh uses the prey, illumination, defense, andcommunications. because Hue light penetrates further in the depths of the ocean. emission and produces thermal y, a gene for some fishes, and squid, the light-emitting (FMNHal called luciferin. reaction requires oxygen and is driven by the enzyme luciferase. As reult, and emission of light, perhaps as many as 50.000 mole- ram negative bacill The most common organisms used in simple ations and xperiments, Vibrio fischeri Vibrio phospbo- nonpathogenic and provide stunning results. Strange but True! toilets. occasionally witness a strange glow in their This is the seawater with bioluminescent organisms in the toilets. 18.5 A nt bacteria and B bacteria glowing in the dark. Procedure 1 Bioluminescent organisms This procedure will demonstrate the bioluminescence J Sterile petri dishes with growth 1 Clean and disinfect your workspace. Bring the culture into a dark area, and Pure culture of Vibrio fischeri gently shake the culture tube. Record 2 Gently dip the end of a sterile cotton swab into the culture tube. Use aseptic techni ques (discussed in Exercise 18A prepare a smear of vibrio spp seal the petri dish with tape or Parafilm. Using a wax the date on the petri dish. The Good, the Bad, and the Ugly: Chapter 18

Solution

Ans:

1. Major diseases and control measures by antibiotics

2. Common antibiotics and their target

1. Beta-lactams : prevent bacteria from constructing a cell wall, by binding to PBP (Penicillin-binding proteins) which are enzymes inside bacterial cells involved in the final stages (cross-linking of the peptide subunits) in the synthesis of peptidoglycan, which is the major component of bacterial cell walls. Contain a beta-lactam \'ring\' which attaches to the active site of the bacterial enzymes. Eg: Pencilllin

2. Macrolides:

Eg: erythromycin

3. Tetracyclines : Act as bacterial protein synthesis inhibitors

Eg: lymecycline

3. What is luciferase: Is a oxidative enzymes that produce bioluminescence

4. List bioluminescent organisms

·         Firefly- Photinus pyralis

·         Sea pansy- Renilla reniformis

·         Bacteria-Vibrio fischeri, Vibrio haweyi, and Vibrio harveyi.

·         Dinoflagellate-Dinoflagellate luciferase

·         Copepod- Metridia longa.

5. Relationship between ATP and bioluminescence:

Bioluminescence is the ability of living things to emit light. It is found in

The molecular details vary from organism to organism, but each involves

The more ATP available, the brighter the light. In fact, firefly luciferin and luciferase are commercially available for measuring the amount of ATP in biological materials.

Fireflies use their flashes to attract mates. The pattern differs from species to species. In one species, the females sometimes mimic the pattern used by females of another species. When the males of the second species respond to these \"femmes fatales\", they are eaten.

Eg: How Fireflies Control their Flashing

Barry Trimmer and his colleagues at Tufts University have recently discovered how fireflies turn their luminescent organs — called lanterns — on.