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The presence of pyrite in the aggregate used to make concrete can lead to severe deterioration as pyrite oxidizes. [51] In early 2009, problems with Chinese drywall imported into the United States after Hurricane Katrina were attributed to pyrite oxidation, followed by microbial sulfate reduction which released hydrogen sulfide gas ( H 2 S ).
Macronutrients are defined as a class of chemical compounds which humans consume in relatively large quantities compared to vitamins and minerals which provide humans with energy. Fat has a food energy content of 38 kilojoules per gram (9 kilocalories per gram) proteins and carbohydrates 17 kJ/g (4 kcal/g). [2]
It can play this role because the Ca 2+ ion forms stable coordination complexes with many organic compounds, especially proteins; it also forms compounds with a wide range of solubility, enabling the formation of the skeleton. [67] Food sources include yogurt, milk, cheese, leafy greens, tofu, and fortified beverages. [68]
Protein can be found in virtually all foods, as it makes up cellular material, though certain methods of food processing may reduce the amount of protein in a food. [39] Humans can also obtain energy from ethanol, which is both a food and a drug, but it provides relatively few essential nutrients and is associated with nutritional deficiencies ...
The sources of energy can be light or chemical compounds; the sources of carbon can be of organic or inorganic origin. [ 1 ] The terms aerobic respiration , anaerobic respiration and fermentation ( substrate-level phosphorylation ) do not refer to primary nutritional groups, but simply reflect the different use of possible electron acceptors in ...
Average dietary energy supply by region. A particular diet may be chosen to promote weight loss or weight gain. Changing a person's dietary intake, or "going on a diet", can change the energy balance, and increase or decrease the amount of fat stored by the body. [2]
Food energy is chemical energy that animals (including humans) derive from their food to sustain their metabolism, including their muscular activity. [ 1 ] Most animals derive most of their energy from aerobic respiration , namely combining the carbohydrates , fats , and proteins with oxygen from air or dissolved in water . [ 2 ]
Marcasite reacts more readily than pyrite under conditions of high humidity. The product of this disintegration is iron(II) sulfate and sulfuric acid. The hydrous iron sulfate forms a white powder consisting of the mineral melanterite, FeSO 4 ·7H 2 O. [13] This disintegration of marcasite in mineral collections is known as "pyrite decay".