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  2. Biological roles of the elements - Wikipedia

    en.wikipedia.org/wiki/Biological_roles_of_the...

    Non-toxic; in humans, it often substitutes for calcium. [11] sulfur: 16: 5: Sulfur is essential and ubiquitous, partly because it is part of the amino acids cysteine and methionine. Many metals that appear as enzyme cofactors are bound by cysteine, and methionine is essential for protein synthesis. Toxic in some forms. tantalum: 73: 1c

  3. Metal toxicity - Wikipedia

    en.wikipedia.org/wiki/Metal_toxicity

    Toxic metals can bioaccumulate in the body and in the food chain. [5] Therefore, a common characteristic of toxic metals is the chronic nature of their toxicity. This is particularly notable with radioactive heavy metals such as radium , which imitates calcium to the point of being incorporated into human bone, although similar health ...

  4. Sulfur metabolism - Wikipedia

    en.wikipedia.org/wiki/Sulfur_metabolism

    From the sulfide they form the amino acids cysteine and methionine, sulfolipids, and other sulfur compounds. Animals obtain sulfur from cysteine and methionine in the protein that they consume. Sulfur is the third most abundant mineral element in the body. [21] The amino acids cysteine and methionine are used by the body to make glutathione.

  5. Food chain - Wikipedia

    en.wikipedia.org/wiki/Food_chain

    Food chain in a Swedish lake. Osprey feed on northern pike, which in turn feed on perch which eat bleak which eat crustaceans.. A food chain is a linear network of links in a food web, often starting with an autotroph (such as grass or algae), also called a producer, and typically ending at an apex predator (such as grizzly bears or killer whales), detritivore (such as earthworms and woodlice ...

  6. Sulfur-reducing bacteria - Wikipedia

    en.wikipedia.org/wiki/Sulfur-reducing_bacteria

    Sulfur reduction metabolism is an ancient process, found in the deep branches of the phylogenetic tree. [15] Sulfur reduction uses elemental sulfur (S 0) and generates hydrogen sulfide (H 2 S) as the main end product. This metabolism is largely present in extreme environments where, especially in recent years, many microorganisms have been ...

  7. Consumer (food chain) - Wikipedia

    en.wikipedia.org/wiki/Consumer_(food_chain)

    Within an ecological food chain, consumers are categorized into primary consumers, secondary consumers, and tertiary consumers. [3] Primary consumers are herbivores, feeding on plants or algae. Caterpillars, insects, grasshoppers, termites and hummingbirds are all examples of primary consumers because they only eat autotrophs (plants).

  8. Organosulfur chemistry - Wikipedia

    en.wikipedia.org/wiki/Organosulfur_chemistry

    Humans and other animals have an exquisitely sensitive sense of smell toward the odor of low-valent organosulfur compounds such as thiols, sulfides, and disulfides. Malodorous volatile thiols are protein-degradation products found in putrid food, so sensitive identification of these compounds is crucial to avoiding intoxication.

  9. Primary nutritional groups - Wikipedia

    en.wikipedia.org/wiki/Primary_nutritional_groups

    Sulfur-oxidizing, iron, and anammox bacteria as well as methanogens are chemolithoautotrophs, using inorganic energy, electron, and carbon sources. Chemolithoheterotrophs are rare because heterotrophy implies the availability of organic substrates, which can also serve as easy electron sources, making lithotrophy unnecessary.