By Editors Chemosynthesis Definition Chemosynthesis is the conversion of inorganic carbon-containing compounds into organic matter such as sugars and amino acids.
Overview[ edit ] Humans and other animals need a minimum intake of food energy to sustain their metabolism and to drive their muscles. Foods are composed chiefly of carbohydratesfatsproteinswatervitaminsand minerals.
Carbohydrates, fats, proteins, and water represent virtually all the weight of food, with vitamins and minerals making up only a small percentage of the weight. Carbohydrates, fats, and proteins comprise ninety percent of the dry weight of foods.
Water, minerals, vitamins, and cholesterol are not broken down they are used by the body in the form in which they are absorbed and so cannot be used for energy.
Using the International System of Unitsresearchers measure energy in joules J or in its multiples; the kilojoule kJ is most often used for food-related quantities. An older metric system unit of energy, still widely used in food-related contexts, is the calorie ; more precisely, the "food calorie", "large calorie" or kilocalorie kcal or Calequal to joules.
Within the European Unionboth the kilocalorie "kcal" and kilojoule "kJ" appear on nutrition labels. In many countries, only one of the units is displayed; in Canada and the United States labels spell out the unit as "calorie" or as "Calorie".
However, the convention is to use the heat of the oxidation reaction producing liquid water.
Conventional food energy is based on heats of combustion in a bomb calorimeter and corrections that take into consideration the efficiency of digestion and absorption and the production of urea and other substances in the urine.
The American chemist Wilbur Atwater worked these corrections out in the late 19th century  see Atwater system for more detail. In the United States, the equivalent mandatory labels display only "Calories" kilocalories often as a substitute for the name of the quantity being measured, food energy; an additional kilojoules figure is optional and is rarely used.
In Australia and New Zealand, the food energy must be stated in kilojoules and optionally in kilocalories as welland other nutritional energy information is similarly conveyed in kilojoules. The reason for this is that direct calorimetry also burns the dietary fiberand so does not allow for fecal losses; thus direct calorimetry would give systematic overestimates of the amount of fuel that actually enters the blood through digestion.
What are used instead are standardized chemical tests or an analysis of the recipe using reference tables for common ingredients  to estimate the product's digestible constituents proteincarbohydratefatetc. These results are then converted into an equivalent energy value based on the following standardized table of energy densities.
The use of such a simple system has been criticized for not taking into consideration other factors pertaining to the influence of different foods on obesity.Energy from chemosynthesis, and particularly from volcanic vents along mid-ocean ridges, is quite interesting, but globally is very small as compared to photosynthesis.
For many animals and bacteria, the energy source, through food webs, is based directly in higher plants and algae. Chemosynthesis Most life on Earth is dependent upon photosynthesis, the process by which plants make energy from sunlight.
However, at hydrothermal vents in the deep ocean a unique ecosystem has evolved in the absence of sunlight, and its source of energy is completely different: chemosynthesis. Apr 09, · Chemosynthetic bacteria are organisms that use inorganic molecules as a source of energy and convert them into organic substances.
Chemosynthetic bacteria, unlike plants, obtain their energy from the oxidation of inorganic molecules, rather than iridis-photo-restoration.coms: 6. Chemosynthesis uses chemical nutrients as an energy source, unlike photosynthesis, which uses sunlight.
Although most life on Earth uses photosynthesis to obtain energy, there are groups of bacteria known as chemosynthetic autotrophs that use chemosynthesis instead.
Some microorganisms derive energy from chemical reactions that don't require light and use this energy to assemble organic molecules through a process called chemosynthesis. These organisms are called chemolithoautotrophs or simply chemoautotrophs.
The inorganic “energy source” is usually a molecule that has electrons to spare, such as hydrogen gas, hydrogen sulfide, ammonia, or ferrous iron. Like photosynthesis and cellular respiration, chemosynthesis uses an electron transport chain to synthesize ATP.