enow.com Web Search

Search results

  1. Results from the WOW.Com Content Network
  2. Composition of the human body - Wikipedia

    en.wikipedia.org/wiki/Composition_of_the_human_body

    Parts-per-million cube of relative abundance by mass of elements in an average adult human body down to 1 ppm. About 99% of the mass of the human body is made up of six elements: oxygen, carbon, hydrogen, nitrogen, calcium, and phosphorus. Only about 0.85% is composed of another five elements: potassium, sulfur, sodium, chlorine, and magnesium.

  3. Biomolecule - Wikipedia

    en.wikipedia.org/wiki/Biomolecule

    Most biomolecules are organic compounds, and just four elements — oxygen, carbon, hydrogen, and nitrogen —make up 96% of the human body 's mass. But many other elements, such as the various biometals, are also present in small amounts. The uniformity of both specific types of molecules (the biomolecules) and of certain metabolic pathways ...

  4. Nicotinamide adenine dinucleotide - Wikipedia

    en.wikipedia.org/wiki/Nicotinamide_adenine_di...

    Found in all living cells, NAD is called a dinucleotide because it consists of two nucleotides joined through their phosphate groups. One nucleotide contains an adenine nucleobase and the other, nicotinamide. NAD exists in two forms: an oxidized and reduced form, abbreviated as NAD+ and NADH (H for hydrogen), respectively.

  5. Reactive oxygen species - Wikipedia

    en.wikipedia.org/wiki/Reactive_oxygen_species

    Several grams are produced per day in the human body within the mitochondria. [5] O 2 + e − → O − 2. Competing with its formation, superoxide is destroyed by the action of superoxide dismutases, enzymes that catalyze its disproportionation: 2 O − 2 + 2H + → O 2 + H 2 O 2. hydrogen peroxide (H 2 O 2) is also produced as a side product ...

  6. Cellular respiration - Wikipedia

    en.wikipedia.org/wiki/Cellular_respiration

    Cellular respiration is the process by which biological fuels are oxidized in the presence of an inorganic electron acceptor, such as oxygen, to drive the bulk production of adenosine triphosphate (ATP), which contains energy. Cellular respiration may be described as a set of metabolic reactions and processes that take place in the cells of ...

  7. Bicarbonate buffer system - Wikipedia

    en.wikipedia.org/wiki/Bicarbonate_buffer_system

    Bicarbonate buffer system. Carbon dioxide, a by-product of cellular respiration, is dissolved in the blood, where it is taken up by red blood cells and converted to carbonic acid by carbonic anhydrase. Most of the carbonic acid then dissociates to bicarbonate and hydrogen ions. The bicarbonate buffer system is an acid-base homeostatic mechanism ...

  8. Biohydrogen - Wikipedia

    en.wikipedia.org/wiki/Biohydrogen

    Biohydrogen is H 2 that is produced biologically. [1] Interest is high in this technology because H 2 is a clean fuel and can be readily produced from certain kinds of biomass, [2] including biological waste. [3] Furthermore some photosynthetic microorganisms are capable to produce H 2 directly from water splitting using light as energy source ...

  9. Acidosis - Wikipedia

    en.wikipedia.org/wiki/Acidosis

    For acidosis referring to acidity of the urine, see Renal tubular acidosis. Acidosis is a biological process producing hydrogen ions and increasing their concentration in blood or body fluids. pH is the negative log of hydrogen ion concentration and so it is decreased by a process of acidosis.