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  2. Chemical reaction - Wikipedia

    en.wikipedia.org/wiki/Chemical_reaction

    Chemical reactions are determined by the laws of thermodynamics. Reactions can proceed by themselves if they are exergonic, that is if they release free energy. The associated free energy change of the reaction is composed of the changes of two different thermodynamic quantities, enthalpy and entropy: [17]

  3. Metabolism - Wikipedia

    en.wikipedia.org/wiki/Metabolism

    Metabolism (/ m ə ˈ t æ b ə l ɪ z ə m /, from Greek: μεταβολή metabolē, "change") is the set of life-sustaining chemical reactions in organisms.The three main functions of metabolism are: the conversion of the energy in food to energy available to run cellular processes; the conversion of food to building blocks of proteins, lipids, nucleic acids, and some carbohydrates; and the ...

  4. Chemistry - Wikipedia

    en.wikipedia.org/wiki/Chemistry

    Chemistry is the scientific study of the properties and behavior of matter. [1] It is a physical science within the natural sciences that studies the chemical elements that make up matter and compounds made of atoms, molecules and ions: their composition, structure, properties, behavior and the changes they undergo during reactions with other substances.

  5. Chemical thermodynamics - Wikipedia

    en.wikipedia.org/wiki/Chemical_thermodynamics

    Chemical thermodynamics is the study of the interrelation of heat and work with chemical reactions or with physical changes of state within the confines of the laws of thermodynamics. Chemical thermodynamics involves not only laboratory measurements of various thermodynamic properties, but also the application of mathematical methods to the ...

  6. Thermochemistry - Wikipedia

    en.wikipedia.org/wiki/Thermochemistry

    Thermochemistry is the study of the heat energy which is associated with chemical reactions and/or phase changes such as melting and boiling. A reaction may release or absorb energy, and a phase change may do the same. Thermochemistry focuses on the energy exchange between a system and its surroundings in the form of heat. Thermochemistry is ...

  7. Biological roles of the elements - Wikipedia

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

    A large fraction of the chemical elements that occur naturally on the Earth's surface are essential to the structure and metabolism of living things. Four of these elements (hydrogen, carbon, nitrogen, and oxygen) are essential to every living thing and collectively make up 99% of the mass of protoplasm. [1]

  8. Biological process - Wikipedia

    en.wikipedia.org/wiki/Biological_process

    Biological processes are made of many chemical reactions or other events that are involved in the persistence and transformation of life forms. [1] Regulation of biological processes occurs when any process is modulated in its frequency, rate or extent.

  9. Reactivity (chemistry) - Wikipedia

    en.wikipedia.org/wiki/Reactivity_(chemistry)

    The chemical reactivity of a substance can refer to the variety of circumstances (conditions that include temperature, pressure, presence of catalysts) in which it reacts, in combination with the: variety of substances with which it reacts, equilibrium point of the reaction (i.e., the extent to which all of it reacts), and; rate of the reaction.