Please do not use frog, camel 2. Design/invent an animal/plant/microbe/alien tha
ID: 272262 • Letter: P
Question
Please do not use frog, camel 2. Design/invent an animal/plant/microbe/alien that lives in an extreme habitat. Make sure to describe the aspects of the environment that make it "extreme". You must include a basic description of the organism (size, shape, major body structures -as appropriate). For three of these four body systems--gas exchange, feeding & digestion, osmoregulation & excretion and/or circulation--describe what is special/unique/different from a "normal" organism that allows it to survive in its environment. Also include at least one more system (as appropriate for your organism) out of these: reproduction, endocrine, muscular/skeletal system (locomotion), immune/defense or nervous system/sensory organs. (15 points) [Sketches are appreciated but not required!]Explanation / Answer
Halophiles are salt-loving organisms that inhabit hypersaline environments like hypersaline salt lakes. They have the ability to balance the osmotic pressure of the environment and resist the denaturing effects of salts on proteins. These extreme halophiles grow best at the highest salinities (3.4–5 molL21 NaCl). This makes them a very good example for this question
One such example is H. salinarum which has can has the ability to grow in salt lakes where oxygen is not available. Though it is an obligate aerobe, it is able to survive in low-oxygen conditions by utilizing light-energy. H. salinarum express the membrane protein bacteriorhodopsin which acts as a light-driven proton pump, their ability to grow
in the absence of oxygen is due to dissimilatory nitrate reduction and denitrification, fermentation of different sugars,
the breakdown of arginine, and use of light energy mediated by retinal pigments.
Features :
Halobacteria are single-celled, rod-shaped microorganisms
The main source of their chemical energy is amino acids mainly arginine and aspartate
They have distinctive features such as gas vesicles, purple membrane, and red-orange carotenoids.
Proteins of halobacteria are either resistant to high salt concentrations or require salts for activity.
(i) The purple membrane, specialized regions of the cell membrane that contain a two-dimensional crystalline lattice of a chromoprotein, bacteriorhodopsin. Bacteriorhodopsin contains a protein moiety (bacterioopsin) and a covalently bound chromophore (retinal) and acts as a light-dependent transmembrane proton pump.
(ii) produce large quantities of red-orange carotenoids. Carotenoids have been shown to be necessary for stimulating an active photo repair system for repair of thymine dimers resulting from ultraviolet radiation.