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  2. Macromolecule - Wikipedia

    en.wikipedia.org/wiki/Macromolecule

    A macromolecule is a very large molecule important to biological processes, such as a protein or nucleic acid. It is composed of thousands of covalently bonded atoms. Many macromolecules are polymers of smaller molecules called monomers. The most common macromolecules in biochemistry are biopolymers (nucleic acids, proteins, and carbohydrates ...

  3. Chemical compound - Wikipedia

    en.wikipedia.org/wiki/Chemical_compound

    A chemical compound is a chemical substance composed of many identical molecules (or molecular entities) containing atoms from more than one chemical element held together by chemical bonds. A molecule consisting of atoms of only one element is therefore not a compound. A compound can be transformed into a different substance by a chemical ...

  4. Cellulose - Wikipedia

    en.wikipedia.org/wiki/Cellulose

    Cellulose is an organic compound with the formula (C 6 H 10 O 5) n, a polysaccharide consisting of a linear chain of several hundred to many thousands of β(1→4) linked D-glucose units. [3] [4] Cellulose is an important structural component of the primary cell wall of green plants, many forms of algae and the oomycetes.

  5. Abiogenesis - Wikipedia

    en.wikipedia.org/wiki/Abiogenesis

    Life functions through the specialized chemistry of carbon and water, and builds largely upon four key families of chemicals: lipids for cell membranes, carbohydrates such as sugars, amino acids for protein metabolism, and nucleic acid DNA and RNA for the mechanisms of heredity.

  6. Urea - Wikipedia

    en.wikipedia.org/wiki/Urea

    The structure of the molecule of urea is O=C(−NH 2) 2.The urea molecule is planar when in a solid crystal because of sp 2 hybridization of the N orbitals. [8] [9] It is non-planar with C 2 symmetry when in the gas phase [10] or in aqueous solution, [9] with C–N–H and H–N–H bond angles that are intermediate between the trigonal planar angle of 120° and the tetrahedral angle of 109.5°.

  7. Ammonia - Wikipedia

    en.wikipedia.org/wiki/Ammonia

    Ammonia is a direct or indirect precursor to most manufactured nitrogen-containing compounds. It is the precursor to nitric acid, which is the source for most N-substituted aromatic compounds. Amines can be formed by the reaction of ammonia with alkyl halides or, more commonly, with alcohols: CH 3 OH + NH 3 → CH 3 NH 2 + H 2 O

  8. Amino acid - Wikipedia

    en.wikipedia.org/wiki/Amino_acid

    Amino acid. Structure of a typical L -alpha-amino acid in the "neutral" form. Amino acids are organic compounds that contain both amino and carboxylic acid functional groups. [1] Although over 500 amino acids exist in nature, by far the most important are the 22 α-amino acids incorporated into proteins. [2]

  9. Protein - Wikipedia

    en.wikipedia.org/wiki/Protein

    A protein is a polyamide. Secondary structure: regularly repeating local structures stabilized by hydrogen bonds. The most common examples are the α-helix, β-sheet and turns. Because secondary structures are local, many regions of different secondary structure can be present in the same protein molecule.