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  2. Biological roles of the elements - Wikipedia

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

    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] Phosphorus and sulfur are also common essential elements, essential to the structure of nucleic acids and amino acids, respectively.

  3. Nucleic acid - Wikipedia

    en.wikipedia.org/wiki/Nucleic_acid

    Nucleic acids RNA (left) and DNA (right). Nucleic acids are large biomolecules that are crucial in all cells and viruses. [1] They are composed of nucleotides, which are the monomer components: a 5-carbon sugar, a phosphate group and a nitrogenous base. The two main classes of nucleic acids are deoxyribonucleic acid (DNA) and ribonucleic acid ...

  4. DNA - Wikipedia

    en.wikipedia.org/wiki/DNA

    At the time, "yeast nucleic acid" (RNA) was thought to occur only in plants, while "thymus nucleic acid" (DNA) only in animals. The latter was thought to be a tetramer, with the function of buffering cellular pH. [199] [200] In 1937, William Astbury produced the first X-ray diffraction patterns that showed that DNA had a regular structure. [201]

  5. 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 ...

  6. CHNOPS - Wikipedia

    en.wikipedia.org/wiki/CHNOPS

    The most known chemical elements whose covalent combinations make up most biological molecules on Earth. [2] All of these elements are nonmetals . In animals in general, the four elements—C, H, N, and O—compose about 96% of the weight, and major minerals (macrominerals) and minor minerals (also called trace elements ) compose the remainder.

  7. Hershey–Chase experiment - Wikipedia

    en.wikipedia.org/wiki/Hershey–Chase_experiment

    Radioactive sulfur-35 was used to label the protein sections of the T2 phage, because sulfur is contained in protein but not DNA. [ 6 ] Hershey and Chase inserted the radioactive elements in the bacteriophages by adding the isotopes to separate media within which bacteria were allowed to grow for 4 hours before bacteriophage introduction.

  8. Nucleic acid structure - Wikipedia

    en.wikipedia.org/wiki/Nucleic_acid_structure

    Nucleic acids are formed when nucleotides come together through phosphodiester linkages between the 5' and 3' carbon atoms. [3] A nucleic acid sequence is the order of nucleotides within a DNA (GACT) or RNA (GACU) molecule that is determined by a series of letters.

  9. Nucleotide base - Wikipedia

    en.wikipedia.org/wiki/Nucleotide_base

    DNA and RNA also contain other (non-primary) bases that have been modified after the nucleic acid chain has been formed. In DNA, the most common modified base is 5-methylcytosine (m 5 C). In RNA, there are many modified bases, including those contained in the nucleosides pseudouridine (Ψ), dihydrouridine (D), inosine (I), and 7-methylguanosine ...