Biology Lectures winter term 2008 1 st year of Pharmacy study
3 rd Lecture Chemical composition of living matter chemical basis of life. Atoms, molecules, organic compounds carbohydrates, lipids, proteins, nucleic acids
Atoms -protons,neutrons,electrons electrons electrons
Macroelements H,O,C,N,P,S,Na,K,Cl,Fe,Mg Microelements I,Mn,F,Zn,Cu,Co,Se,...
Bonds of atoms
Molecules Bond ionic, covalent, polar and non-polar metán Sodík Chlór NaCl
H2O
ATP - energy - Structure of Nucleic acides - signal molecule
Macromolecules - sugars -saccharides -lipids -proteins - nucleic acids
Sugars - saccharides Monosaccharides - pentose ribose, deoxyribose - hexose glucose, fructose, galactose
Sugars - saccharides disascharides - saccharum, maltose, lactose
Sugars - saccharides Polysaccharides - starch, glycogen, cellulose glucose glucogen
Proteins
Proteins
Proteins biogenic amino acids, names a codes Aspartic Acid Asp D Glutamic Acid Glu E Phenylanine Phe F Glycine Gly G Alanine Ala A Cystine Cys C Histidine His H Isoleucine Ile I Lysine Lys K Leucine Leu L Methionine Met M Asparagine Asn N Proline Pro P Glutamine Gln Q Arginine Arg R Serine Ser S Threonine Thr T Valine Val V Tryptophan Trp W Tyrosine Tyr Y
Amino acids
Amino acids sequence 3-D structure Function of protein
Genetic code
Peptide bond Proteins
Proteins
Folding of proteins
Amino Acid Sequence 3-D Structure Protein Function
α, β Helix pleadted sheet
3-D structure of proteins 1. Primary structure amino acids sequence (determine by mrna) 2. secondary α-or β-helix; pleated sheet (H-bonds) 3. Tertiary 3-D protein structure (S-S bonds) 4. Quaternary the final structure of proteins (subunits, prostetic units and etc.)
3-D Structure of proteins
Three ways of proteins bonds
Proteins are hungry
Amino Acid Sequence 3-D Structure Protein Function
Nucleic acids DNA-RNA
Nucleic acids DNA
Chromosome Nucleus consists one or more molecules DNA organized into chromosomes Human: 22 pars autozomes 1 par sex chromosome Human karyotypes
Human and mouse chromosomes:
DNA chemical structure
Double helix of DNA
Double helix Two complementary DNA strains Spring will be 52th anniversary of its discovery
Detection of DNA
Detection of DNA
Red increase of sample transcripts Green increase of sample transcripts Yellow equal abundance Limit of Detection: 1 in 30,000 transcripts ~ 20 transcripts/cell
Affymetrix GeneChip Limits: 1: 100,000 transcripts ~ 5 transcripts/cell Affymetrix GeneChip
3-D Structure of DNA in nucleus Nuclear membrane Chromatin fiber Chromatin fiber (30 nm dia.) H1 Nucleosomes H1 Nuclear pore DNA } Other Chromatin factors Nuclear matrix
DNA-protein complex
DNA folding
Chromatin structure
DNA is wrapped Chromatin around histone structure proteins as chromatin
The Obstacles are Regulated: Histone Modifications A Histone Code? Bromo Domain Chromo Domain regulation of transcription complex of genes to the DNA locus protection of specific genes
All cells the same DNA - different reading of DNA - differentiation of cells
Histones play Key role in Regulation of gene expression
Transcription and Processing DNA in blue PolyA+RNA in red PolyA+RNA in red (a spliceosomal component) in green Overlap (red + green) = yellow
RNA Ribonucleic Similar as DNA Tymine (T) is substituted by uracile (U) RNA can be: One-strain helix Double strains helix Hybridisated with DNA
RNA RNA is usually one strain It forms the 3-D secondary and tertiary structure The most important is extreme variability of the RNA molecules - sequence
trna: sequence, 3-D structure
mrna Messenger RNA Linear molecule coded genetic information copy from DNA Transcription: process of copy mrna from DNA
mrna modification Eukaryotic genes are built: Exons: coding regions Introns: non-coding regions splicing: cut of introns from molecule of mrna and link the exons After this modification of mrna is translated to sequence of protein
mrna modification Image source: http://departments.oxy.edu/biology/stillman/bi221/111300/processing_of_hnrnas.htm
trna Transfer RNA Precise 3-D structure The translation process of protein
trna structure
trna Specific trna for each amino acid Determine by 3 nucleotide - anticodone (complementary with mrna) Translation: process of prescription of codons of mrna to sequence of amino acids to protein
trna
trna: sequence, 3-D structure
trna structure
rrna secondary structure
16S ribosomal RNA
T. thermophilus - Ramakrishnan et al., Cell, 2002
Lipids
Schematic Diagram of a phospholipid molecule (phosphatidylcholine)
Phospholipids Membranes of mammalian cells contain 3 major phospholipids Classified according to the polar headgroup
Choline head-group Polar Saturated fatty acid Unsaturated fatty acid Phosphatidylcholine Nonpolar Differences in the length and degree of saturation of fatty acids affect their ability to pack & hence the fluidity of the bilayer
Amphipathic A, formula B, schematic drawing C, space-filling model
Cholesterol is oriented in the membrane between phospholipid molecules with its polar end towards the outside surface of the monolayer and its hydrophobic end projecting into the interior of the membrane
Lodish et al, Fig 5-30