Bruno Sopko

 Glucose  Glycogen  Glycoproteins  Glycolipids  Proteoglycans

 polyhydroxyaldehydes and ketones  3-8 carbons + functional group  chiral compounds  groups: ◦ Monosaccharides ◦ Disaccharides ◦ Polysaccharides ◦ Modified saccharides An aldoseA ketose

Enantiomers - „mirror images“ (rotate polarized light in opposite directions → optical activity) 2 n of possible stereoisomers (half that many pairs of enantiomers) n - the number of chiral carbons (e.g. glucose - 16 stereoisomers) a mirror D sugar → the OH group on the chiral carbon farthest from the carbonyl group pointing to the right in a Fischer projection L sugar → the OH group on the chiral carbon farthest from the carbonyl group pointing to the right in a Fischer projection Fischer projection:

Mutarotation  change in rotation of plane- polarized light resulting from the equilibrium between cyclic anomers and the open-chain form of a sugar Anomers  cyclic sugars that differ only in positions of substituents at the anomeric carbon

Reducing sugars react in basic solution with a mild oxidizing agent In basic solutions, all monosaccharides are reducing sugars

Hydrolysis of a disaccharide (during digestion of carbohydrates) Glycosidic bond → bond between the anomeric carbon of a monosaccharide and an -OR group

Aldoses Pentoses Hexoses  in RNA and NADH  in polysaccharides in the walls of plant cells  „blood“ sugar (energy)  in cellulose and starch  in glycogen (as a source of energy in an organism)  in lactose (milk), glycolipids and glycoproteins  converted to glucose  galactosemia  in glycolipids and glycoproteins

Ketoses: D-RibuloseD-Fructose  an intermediate in the pentose phoshate pathway  in fruit juices and in honey  in sucrose  converted to glucose Deoxyaldoses: 2-deoxy-D-ribose  in DNA

Acetylated amino sugars: Acidic sugars: N-Acetyl-D- glucosamine N-Acetyl-D- galactosamine D-Glucuronic acidN-Acetylneuraminic acid (sialic)  in glycoproteins  in glycosaminoglycans in connective tissue  conjugation of bile acids  in glycoproteins

Maltose  a breakdown product of the starch Sucrose Lactose  cane sugar, beet sugar  non-reducing sugar  milk sugar (4,5% - 7%)  lactose intolerance (reduced activity of lactase)

Cellulose  ß-D-Glucose, ß-1,4 link  the fibrous substance that provides structure in plants  humans cannot hydrolyze cellulose

Starch  α-D-Glucose  source of energy in plants  fully digestible - an essential part of the human diet (the grains wheat, potatoes, rice) 1. Amylose (20%, soluble in water)  α-1,4 link 2. Amylopectin (80%, not water soluble)  α-1,6 branches (every 25 units)

Glycogen  α-D-Glukose, α-1,4 and α-1,6 link  source of energy in animals (liver, muscles)

Hyaluronic acid  25,000 disaccharide units  form very viscous mixture  in connective tissue, synovial fluid, vitreous humour Chondroitin sulfate  in tendons and cartilage Glucuronic acid N-Acetylglucosamine Glucuronic acid N-Acetylgalactosamine sulfate

Heparin  contains sulfate groups (negative charges)  anticoagulant - prevents the clotting of blood (binds to the clotting factors)

 polymers in molar mass in the range 20kDa to 4GDa or more  two basic types : DNA and RNA  during last twenty years rapid development – molecular biology and genetics, genetic engineering etc.

 phosphoric acid

 pentose (5 carbon sugar) D-ribose 2-deoxy-D-ribose (RNA) (DNA)

 heterocyclic bases (nucleobases) ◦ pyrimidine bases ◦ purine bases pyrimidine uracil thymine cytosine (RNA) (DNA) purine adenine guanine

Adenosine guanosine cytidine

Nucleotide consists of nucleoside which is esterified by phosphoric acid at either 5´ (usually and exclusively in nucleic acids) or 3´-hydroxyl group of pentose moiety. Nucleotide is monomeric unit of polymeric nucleic acids (polynucleotides) deoxyribonucleotides – dAMP, dGMP, dTMP and dCMP (monomers of DNA) ribonucleotides – AMP, GMP, UMP and CMP (monomers of RNA) AMP

 5´-OH group of nucleotide is joined to 3´-OH group of another nucleotide by phosphodiester bond  polynucleotide chain contains 5´- and 3´- end and by convention nucleic acid sequence is written from 5´ to 3´ end

A BZ A B Z

 transfer of information in a gene (DNA) to the protein synthetizing machinery  very heterologous in size and stability, each molecule is template for specific protein sequence  translation of mRNA to protein begins from 5´- terminus  the most of mRNA molecules contains polyA tail at the 3´-hydroxyl teminus (attached adenylate residues)

5´-end capped)

 small molecules (about 75 nucleotides)  7-15% posttranscriptional modified bases.  3' end has always CCA sequence  carries amino acids to the template for protein synthesis  at least 20 species of tRNA in every cell corresponding to each of 20 amino acids  the structure reminds of clover

 integral component of ribosome (specific cytoplasmatic structure for proteosynthesis from mRNA templates)  the bulk of cellular RNA  three rRNAs 28S 18S and 5,8S  catalytic (enzyme like) activity during creation of peptidyl bond

 around 22 nucleotides in length  mediate the recently discovered phenomenon of RNA interference (RNAi)  mediate the downregulation of gene expression - binding to specific mRNAs labelled them for destruction by enzymes called endonucleases

 22–24 nucleotides in length  downregulate gene expression - binding to messenger RNAs (mRNAs) causes preventing mRNAs from being translated into proteins

 important for the biosynthesis of rRNAs,  modify ribosomal RNAs (rRNAs) by organizing the cleavage of the long pre- rRNA into its functional subunits (18S, 5.8S and 28S molecules)

 are constituents of the cellular machinery (spliceosome) that helps to produce mRNA  removing the non-coding regions (introns) of genes and piecing together the coding regions (exons) to be translated into proteins  some of these snRNAs have been shown to be the functional enzymes in the splicing reaction

 an RNA molecule that catalyzes a chemical reaction  from ribonucleic acid enzyme (called also RNA enzyme)  many natural ribozymes catalyze either the hydrolysis of one of their own phosphodiester bonds or the hydrolysis of bonds in other RNA

DNA RNA carbohydrate deoxyriboseribose pyrimidine base thymineuracil structure double-helix single helix stability at high pH resistentcleaved

 This presentation has been made by compilation of the presentations made by RNDr. Miroslava Rovenská, and RNDr. Richard Vytášek, CSc.