bioc

• Many proteins are the apo-part of the highly organised molecular complexes associated with non-protein molecules (prosthetic groups) via covalent, hydrogen and co-ordination bonds.
• Nucleoproteins (prosthetic groups are nucleic acids).
• Nucleic acids have a structure and functions.
• Lipids have a structure, classification, and functions.
• Their derivative is the vitamin A, a critical component in vision regulation.
• Carbohydrates have a structure, classification, and functions.
• Glycoproteins (prosthetic groups are carbohydrates).
• Lipoproteins (prosthetic groups are lipids).
• Chromoproteins (prosthetic groups are coloured compounds like heme, derivatives of vitamin B2).
• Phosphoproteins (prosthetic group is H3PO4).
• Metalloproteins (prosthetic groups are metal cations).
• Nucleic acids are biopolymers, which consist of nucleotides.
• Each nucleotide contains purine/pyrimidine base, pentose sugar and phosphoric acid.
• Nucleotides containing purine base are called purine nucleotides, pyrimidine – pyrimidine nucleotides.
• Pentose sugar is the ribose or deoxyribose.
• If the nucleic acid is formed by ribose containing nucleotides – this is ribonucleic acid (RNA), if by deoxyribose – deoxyribonucleic acid (DNA).
• Nucleotides are named according to the purine/pyrimidine base (adenylic acid, guanylic acid, cytidylic acid, thymylic acid, uridylic acid) with the index “d” (meaning deoxyribose) or “r” meaning ribose.
• Nucleotides form polymer interacting with each other by 3’ - 5’ - phosphodiester bonds.
• Polynucleotide chain forms the primary structure of nucleic acids.
• The plonucleotide chain form antiparallel helices using hydrogen bonds.
• In the case of DNA two antiparallel chain form double helix.
• Chemistry of nucleotide complementarity: Antiparallel chains Adenine Guanine Cytosine Thymine.
• Chargaffs rules: A + G = C + T, A + C = G + T, A/T = 1 and G/C = 1.
• DNA of E. coli is the typical tertiary structure.
• Polysaccharides, such as starch, glycogen, or cellulose, can reach many thousands of units in length.
• The function of the histones is to protect DNA.
• Basic histone proteins interact with DNA having it as a prosthetic group.
• The basic carbohydrate units are called monosaccharides.
• The general chemical formula of an unmodified monosaccharide is (CH2O)n, where n is any number of three or greater.
• Those containing aldehyde groups are called aldoses, keto-group-ketoses.
• DNA exists in the cells in the form of nucleoprotein.
• Super-helices are generated in the tertiary structure of the nucleic acid.
• Carbohydrates, or saccharides, are simple molecules that are straight-chain aldehydes or ketones with many hydroxyl groups added, usually one on each carbon atom that is not part of the aldehyde or ketone functional group.
• DNA stores the information about the protein structure (3 nucleotides encode 1 amino acid).
• The function of nucleic acids is storage and transferring of the genetic information.
• RNA is responsible for transferring this information to be translated into “20 amino acid language” of the proteins.
• Nucleoprotein is packed into nucleosomes.
• Carbohydrates containing between about three to six monosaccharide units are termed oligosaccharides; anything larger than this is a polysaccharide.
• Many carbohydrates contain one or more modified monosaccharide units that have had one or more groups replaced or removed.
• The ratio (G + C)/(A + T) is critical for taxonomic characteristics of living beings (for plants and animals it varies from 0.54 to 0.94 and is always less than 1).