User:Honorsc/sandbox

Heterotroph
Information is relevant and supported by peer-reviewed sources. Article covers a large range of different nutrient assimilation methods among plants and animals alike but is arranged in a confusing manner such that each section contains some information that is not distinct. Article starts by talking about how the term originates from microbes yet gives no specific microbial example.Ideally, article should read from the most general information to the more specific information but the bottom section "Ecology" jumps back to introducing what is heterotroph again with limited highlighting of interactions between organisms. Article covers terms like "litho", "hetero", and "auto" but does not explain their significance in relation to ATP production clearly.Perhaps it will be more helpful to introduce the etymology of these terms first in the top section.For example, in the term "chemoorganoheterotroph", chemo refers to energy source, organo refers to electron source and hetero refers to carbon source.Also,there are some ambiguous language used that may prompt the reader into thinking that heterotrophs are always at an advantage compared to autotrophs. For example,the line "Heterotrophs,by consuming reduced carbon compounds,are able to use all the energy that they obtain from food for growth and reproduction...unlike autotrophs." implies that there is a 100% energy efficiency to produce work when in fact a lot of the energy during respiration is lost as heat and in egestion.

Honorsc (talk) 23:41, 16 September 2017 (UTC)

Function
Gas vesicles occur primarily in aquatic organism as they are used to modulate the cell's buoyancy and modify the cell's position in the water column so it can be optimally located for photosynthesis or move to locations with more or less oxygen.

Function
Gas vesicles occur primarily in aquatic organism as they are used to modulate the cell's buoyancy and modify the cell's position in the water column so it can be optimally located for photosynthesis or move to locations with more or less oxygen .Organisms that could float to the air–liquid interface out competes other aerobes that cannot rise in a water column, through using up oxygen in the top layer.

In addition, gas vesicles can be used to maintain optimum salinity by positioning the organism in specific locations in a stratified body of water to prevent osmotic shock. High concentrations of solute will cause water to be drawn out of the cell by osmosis, causing cell lysis. The ability to synthesize gas vesicles is one of many strategies that allow halophilic organisms to tolerate environments with high salt content.

Evolution
Gas vesicles are likely one of the most early mechanisms of motility among microscopic organisms due to the fact that it is the most widespread form of motility conserved within the genome of prokaryotes, some of which have evolved about 3 billion years ago. Modes of active motility such as flagella movement require a mechanism that could convert chemical energy into mechanical energy, and thus is much more complex and would have evolved later. Functions of the gas vesicles are also largely conserved among species, although the mode of regulation might differ, suggesting the importance of gas vesicles as a form of motility. In certain organism such as enterobacterium; Serratia sp, flagella-based motility and gas vesicle production are regulated oppositely by a single RNA binding protein, RsmA, suggesting alternate modes of environmental adaptation which would have developed into different taxons through regulation of the development between motility and flotation.

Although there is evidence suggesting the early evolution of gas vesicles, plasmid transfer serves as an alternate explanation of the widespread and conserved nature of the organelle. Cleavage of a plasmid in Halobacterium halobium.resulted in the loss of the ability to biosynthesize gas vesicles, indicating the possibility of horizontal gene transfer, which could result in a transfer of the ability to produce gas vesicles among different strains of bacteria.

Quorum Sensing
In ''enterobacterium; Serratia sp. strain ATCC39006'', gas vesicle is produced only when there is sufficient concentration of a signalling molecule, N-acyl homoserine lactone.In this case, the Quorum sensing molecule, N-acyl homoserine lactone acts as a morphogen initiating organelle development. This is advantageous to the organism as resources for gas vesicle production are utilized only when there is oxygen limitation caused by an increase in bacterial population.

Honorsc (talk) 05:08, 8 October 2017 (UTC)