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BiologyLectures – winter term 2008
1st year of Pharmacy study
Chemical composition of living matter – chemical basis of life. Atoms, molecules, organic compounds – carbohydrates, lipids, proteins, nucleic acids
3rd Lecture
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
MoleculesBond – 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
disascharides- saccharum, maltose, lactose
Sugars - saccharides
Polysaccharides - starch, glycogen, cellulose
Sugars - saccharides
glucose
glucogen
Proteins
Proteins
biogenic amino acids, names a codes
Proteins
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 VTryptophan Trp W Tyrosine Tyr Y
Amino acids
Amino acids sequence
3-D structure
Function of protein
Geneticcode
Peptide bond
Proteins
Proteins
Folding of proteins
Amino Acid Sequence
3-D Structure
Protein Function
α, β−Helix pleadted sheet
3-D structure of proteins1. 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
ChromosomeNucleus consists one or more molecules DNA organized intochromosomes
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®
Nuclear membraneChromatin fiber
} Other Chromatinfactors
H1
H1
Nuclear matrix
Nuclear pore
Nucleosomes
DNA
Chromatin fiber(30 nm dia.)
3-D Structure of DNA in nucleus
DNA-protein complex
DNAfolding
Chromatin structure
DNA is wrapped around histone proteins as chromatinChromatin structure
The Obstacles are Regulated: Histone Modifications
A Histone Code?
ChromoDomain
BromoDomain
• 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 ofgene expression
Transcription and Processing
PolyA+RNA in red(a spliceosomal component) in green Overlap (red + green) = yellow
DNA in bluePolyA+RNA in red
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
rRNAsecondarystructure
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
Saturated fatty acid
Unsaturated fatty acid
Differences in the length and degree of saturation of fatty acids affect their
ability to pack& hence the fluidity
of the bilayer
Choline head-group
Polar
Nonpolar
Phosphatidylcholine
Amphipathic
A, formula
B, schematic drawing
C, space-filling model
Cholesterol is oriented in the membrane between phospholipidmolecules 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