Samenvatting Moleculaire en cellulaire biologie BACH 1
Inhoud
Hoofdstuk 1: cellen zijn de fundamentele eenheden van leven .............................................. 8
1.1: soorten cellen en hun evolutie .......................................................................................... 8
1.2: cellen en weefsels in het menselijk lichaam .................................................................... 9
1.3 opbouw van eukaryoten cellen .......................................................................................... 9
1.4: compartimentalisatie van eukaryote cellen ................................................................... 10
1.5: de celcompartimenten (celorganellen) .......................................................................... 10
1.6: isolatie van celorganellen ................................................................................................ 14
differentiële ultracentrifugatie ........................................................................................ 14
densiteitsgradiënt centrifugeren ..................................................................................... 14
Hoofdstuk 2: de chemie van het leven ...................................................................................... 15
2.1: de bio-elementen ............................................................................................................. 15
2.2: De cel is opgebouwd uit koolstofverbindingen ............................................................ 15
2.3: belangrijkste soorten koolstofverbindingen ................................................................. 15
Koolwaterstoffen ............................................................................................................ 15
2.4: water is het meest voorkomende molecule in biologisch materiaal .......................... 18
2.5: soorten chemische bindingen in levende materie ....................................................... 18
Waterstofbruggen .......................................................................................................... 18
Van der Waals interacties ............................................................................................... 18
Hydrofobe interacties ..................................................................................................... 18
Hoofdstuk 3: aminozuren en eiwitten ........................................................................................ 20
Ionisatie van een aminozuur in functie van de pH ............................................................ 20
Optische isomeren van aminozuren ................................................................................ 20
Overzicht aminozuren per groep : (tekeningen: zie blad) ................................................... 21
3.2: De primaire structuur van een eiwit ................................................................................ 23
3.3: de secundaire structuur van eiwitten .............................................................................. 24
3.4: de tertiaire structuur ......................................................................................................... 26
3.5: de quaternaire structuur .................................................................................................. 27
3.6: driedimensionale structuur van eiwitten ........................................................................ 27
3.7: modificaties van eiwitten .................................................................................................. 28
3.8: domeinen in eiwitten ........................................................................................................ 28
3.9: voorbeelden van fibreuze eiwitten ................................................................................. 29
1
, 3.10: voorbeelden van globulaire eiwitten ........................................................................... 30
Antistoffen ..................................................................................................................... 30
Transporteiwitten: .......................................................................................................... 33
Enzymen ........................................................................................................................ 33
Membraaneiwitten: ........................................................................................................ 34
Hoofdstuk 4: DNA deoxyribonucleic acid ................................................................................. 35
4.1: belangrijkste mijlpalen in de geschiedenis van de erfelijkheidsleer .......................... 35
Experiment van Griffith: .................................................................................................. 36
Experiment Hershey-Chase: ........................................................................................... 36
4.2: Deoxyribonucleic acid DNA ............................................................................................ 37
Hoofdstuk 5: DNA-replicatie ....................................................................................................... 41
5.1: replicatie is semi-conservatief ......................................................................................... 41
5.2: de DNA polymerasen ...................................................................................................... 41
5.3: de replicatie vork .............................................................................................................. 41
5.4: de replicatievork is asymmetrisch ................................................................................... 43
5.5 replicatiestart ...................................................................................................................... 43
Replicatie bij prokaryoten: .............................................................................................. 43
Replicatiestart bij eukaryoten: ........................................................................................ 44
5.6: Terminatie van de replicatie ............................................................................................. 45
Prokaryoten: .................................................................................................................. 45
Eukaryoten:.................................................................................................................... 45
5.7: DNA-technologie: de polymerase kettingreactie PCR ................................................. 46
Hoofdstuk 6: DNA – herstelmechanismen................................................................................. 47
6.1: inleiding ............................................................................................................................. 47
6.2: verschillende typen en oorzaken van mutaties ............................................................. 47
Mutaties tijdens het replicatie proces: ............................................................................ 48
Mutaties die niet afhangen van replicatie: ....................................................................... 48
6.3: de cel beschikt over DNA-herstelmechanismen ........................................................... 49
Mismatch repair: ............................................................................................................ 50
Base excision repair BER: ............................................................................................... 51
Nucleotide excision repair: ............................................................................................. 51
Werking van het NER: ..................................................................................................... 52
Herstelmechanismen voor dubbelstrengsbreuken: ......................................................... 52
6.4: de Ames-test...................................................................................................................... 53
Hoofdstuk 7: transcriptie ............................................................................................................. 54
2
, 7.1: de verschillen tussen RNA en DNA ................................................................................. 54
7.2: in welk RNA molecule bevindt zich de boodschap ...................................................... 54
7.3: RNA-polymerasen ............................................................................................................. 55
7.4: transcriptie: initiatie – terminatie PROKARYOTEN ........................................................ 56
7.5: eukaryote transcriptie ....................................................................................................... 58
Het initiatie complex !!! .................................................................................................. 58
Terminatie...................................................................................................................... 59
Hoofdstuk 8: translatie ................................................................................................................. 60
8.1: introductie en herhaling: genetische code.................................................................... 60
8.2: de verschillende soorten RNA ......................................................................................... 61
mRNA ............................................................................................................................ 61
tRNA .............................................................................................................................. 64
rRNA .............................................................................................................................. 65
8.3: het translatie proces ......................................................................................................... 66
Translatie – initiatie ........................................................................................................ 66
Translatie – elongatie ...................................................................................................... 67
Translatie – terminatie .................................................................................................... 68
8.4: antibiotica en translatie .................................................................................................... 68
8.5 vouwing en modificaties van eiwitten na translatie ........................................................ 70
Hoofdstuk 9: genetische variatie ................................................................................................ 71
9.1 Definitie ............................................................................................................................... 71
9.2 genetische variatie bij bacteriën ...................................................................................... 71
Snelle vermenigvuldiging ................................................................................................ 71
Uitwisseling van genetisch materiaal bij prokaryoten ....................................................... 71
Mechanismen van gentransfer ........................................................................................ 73
Conjugatie of mating .................................................................................... 73
Transformatie .............................................................................................. 73
Transductie ................................................................................................. 74
Transpositie ................................................................................................. 74
9.3: genetische variatie bij eukaryoten .................................................................................. 75
Repetitieve sequenties ................................................................................................... 75
LINEs ....................................................................................................... 75
SINEs....................................................................................................... 76
Pseudogenen ........................................................................................... 76
3
, Genetische variatie bij eukaryoten .................................................................................. 76
Seksuele voortplanting en genetische variatie ................................................................. 77
Single Nucleotide Polymorphisms .................................................................................. 78
Copy nummer variations ................................................................................................ 79
Retrovirussen – kanker link ............................................................................................. 79
Hoofdstuk 10: regeling van transcriptie bij prokaryoten ......................................................... 80
10.1: inleiding ........................................................................................................................... 80
10.2: het lactose-operon ......................................................................................................... 80
Definitie van een operon ................................................................................................. 81
de regeling van transcriptie van het lactose operon ......................................................... 81
repressie ..................................................................................................... 81
de-repressie ................................................................................................ 82
activering van het lac-operon ........................................................................ 83
10.3 het tryptofaan operon ..................................................................................................... 84
repressie ..................................................................................................... 84
Attenuatie ................................................................................................... 84
Hoofdstuk 11: transcriptie regeling bij eukaryoten ................................................................. 86
11.1 organisatie van het genoom bij eukaryoten ................................................................. 86
Organisatie van nucleosomen ........................................................................................ 86
Hogere organisatie van chromatine ................................................................................. 87
Transcriptie regeling hangt samen met structuur van chromatine .................... 88
11.2: epi-genetische controle ................................................................................................. 88
Genomic imprinting ........................................................................................................ 89
11.3 transcriptie regeling ........................................................................................................ 90
Enhancers...................................................................................................................... 90
Transcriptie factoren ...................................................................................................... 90
Helix – turn – helix ........................................................................................ 90
Homeodomein............................................................................................. 90
Zink vingers ................................................................................................. 91
Leucine-zipper ............................................................................................. 92
Algemene kenmerken van DNA-bindende domeinen ...................................... 92
Hoe kunnen transactivatiedomeinen de transcriptie van een gen beïnvloeden? 93
Activatiedomeinen zijn eiwit-bindingplaatsen (histonmodificaties) .............. 93
Chromatine remodelling (volgt op de histonmodificaties) ............................ 93
4
Inhoud
Hoofdstuk 1: cellen zijn de fundamentele eenheden van leven .............................................. 8
1.1: soorten cellen en hun evolutie .......................................................................................... 8
1.2: cellen en weefsels in het menselijk lichaam .................................................................... 9
1.3 opbouw van eukaryoten cellen .......................................................................................... 9
1.4: compartimentalisatie van eukaryote cellen ................................................................... 10
1.5: de celcompartimenten (celorganellen) .......................................................................... 10
1.6: isolatie van celorganellen ................................................................................................ 14
differentiële ultracentrifugatie ........................................................................................ 14
densiteitsgradiënt centrifugeren ..................................................................................... 14
Hoofdstuk 2: de chemie van het leven ...................................................................................... 15
2.1: de bio-elementen ............................................................................................................. 15
2.2: De cel is opgebouwd uit koolstofverbindingen ............................................................ 15
2.3: belangrijkste soorten koolstofverbindingen ................................................................. 15
Koolwaterstoffen ............................................................................................................ 15
2.4: water is het meest voorkomende molecule in biologisch materiaal .......................... 18
2.5: soorten chemische bindingen in levende materie ....................................................... 18
Waterstofbruggen .......................................................................................................... 18
Van der Waals interacties ............................................................................................... 18
Hydrofobe interacties ..................................................................................................... 18
Hoofdstuk 3: aminozuren en eiwitten ........................................................................................ 20
Ionisatie van een aminozuur in functie van de pH ............................................................ 20
Optische isomeren van aminozuren ................................................................................ 20
Overzicht aminozuren per groep : (tekeningen: zie blad) ................................................... 21
3.2: De primaire structuur van een eiwit ................................................................................ 23
3.3: de secundaire structuur van eiwitten .............................................................................. 24
3.4: de tertiaire structuur ......................................................................................................... 26
3.5: de quaternaire structuur .................................................................................................. 27
3.6: driedimensionale structuur van eiwitten ........................................................................ 27
3.7: modificaties van eiwitten .................................................................................................. 28
3.8: domeinen in eiwitten ........................................................................................................ 28
3.9: voorbeelden van fibreuze eiwitten ................................................................................. 29
1
, 3.10: voorbeelden van globulaire eiwitten ........................................................................... 30
Antistoffen ..................................................................................................................... 30
Transporteiwitten: .......................................................................................................... 33
Enzymen ........................................................................................................................ 33
Membraaneiwitten: ........................................................................................................ 34
Hoofdstuk 4: DNA deoxyribonucleic acid ................................................................................. 35
4.1: belangrijkste mijlpalen in de geschiedenis van de erfelijkheidsleer .......................... 35
Experiment van Griffith: .................................................................................................. 36
Experiment Hershey-Chase: ........................................................................................... 36
4.2: Deoxyribonucleic acid DNA ............................................................................................ 37
Hoofdstuk 5: DNA-replicatie ....................................................................................................... 41
5.1: replicatie is semi-conservatief ......................................................................................... 41
5.2: de DNA polymerasen ...................................................................................................... 41
5.3: de replicatie vork .............................................................................................................. 41
5.4: de replicatievork is asymmetrisch ................................................................................... 43
5.5 replicatiestart ...................................................................................................................... 43
Replicatie bij prokaryoten: .............................................................................................. 43
Replicatiestart bij eukaryoten: ........................................................................................ 44
5.6: Terminatie van de replicatie ............................................................................................. 45
Prokaryoten: .................................................................................................................. 45
Eukaryoten:.................................................................................................................... 45
5.7: DNA-technologie: de polymerase kettingreactie PCR ................................................. 46
Hoofdstuk 6: DNA – herstelmechanismen................................................................................. 47
6.1: inleiding ............................................................................................................................. 47
6.2: verschillende typen en oorzaken van mutaties ............................................................. 47
Mutaties tijdens het replicatie proces: ............................................................................ 48
Mutaties die niet afhangen van replicatie: ....................................................................... 48
6.3: de cel beschikt over DNA-herstelmechanismen ........................................................... 49
Mismatch repair: ............................................................................................................ 50
Base excision repair BER: ............................................................................................... 51
Nucleotide excision repair: ............................................................................................. 51
Werking van het NER: ..................................................................................................... 52
Herstelmechanismen voor dubbelstrengsbreuken: ......................................................... 52
6.4: de Ames-test...................................................................................................................... 53
Hoofdstuk 7: transcriptie ............................................................................................................. 54
2
, 7.1: de verschillen tussen RNA en DNA ................................................................................. 54
7.2: in welk RNA molecule bevindt zich de boodschap ...................................................... 54
7.3: RNA-polymerasen ............................................................................................................. 55
7.4: transcriptie: initiatie – terminatie PROKARYOTEN ........................................................ 56
7.5: eukaryote transcriptie ....................................................................................................... 58
Het initiatie complex !!! .................................................................................................. 58
Terminatie...................................................................................................................... 59
Hoofdstuk 8: translatie ................................................................................................................. 60
8.1: introductie en herhaling: genetische code.................................................................... 60
8.2: de verschillende soorten RNA ......................................................................................... 61
mRNA ............................................................................................................................ 61
tRNA .............................................................................................................................. 64
rRNA .............................................................................................................................. 65
8.3: het translatie proces ......................................................................................................... 66
Translatie – initiatie ........................................................................................................ 66
Translatie – elongatie ...................................................................................................... 67
Translatie – terminatie .................................................................................................... 68
8.4: antibiotica en translatie .................................................................................................... 68
8.5 vouwing en modificaties van eiwitten na translatie ........................................................ 70
Hoofdstuk 9: genetische variatie ................................................................................................ 71
9.1 Definitie ............................................................................................................................... 71
9.2 genetische variatie bij bacteriën ...................................................................................... 71
Snelle vermenigvuldiging ................................................................................................ 71
Uitwisseling van genetisch materiaal bij prokaryoten ....................................................... 71
Mechanismen van gentransfer ........................................................................................ 73
Conjugatie of mating .................................................................................... 73
Transformatie .............................................................................................. 73
Transductie ................................................................................................. 74
Transpositie ................................................................................................. 74
9.3: genetische variatie bij eukaryoten .................................................................................. 75
Repetitieve sequenties ................................................................................................... 75
LINEs ....................................................................................................... 75
SINEs....................................................................................................... 76
Pseudogenen ........................................................................................... 76
3
, Genetische variatie bij eukaryoten .................................................................................. 76
Seksuele voortplanting en genetische variatie ................................................................. 77
Single Nucleotide Polymorphisms .................................................................................. 78
Copy nummer variations ................................................................................................ 79
Retrovirussen – kanker link ............................................................................................. 79
Hoofdstuk 10: regeling van transcriptie bij prokaryoten ......................................................... 80
10.1: inleiding ........................................................................................................................... 80
10.2: het lactose-operon ......................................................................................................... 80
Definitie van een operon ................................................................................................. 81
de regeling van transcriptie van het lactose operon ......................................................... 81
repressie ..................................................................................................... 81
de-repressie ................................................................................................ 82
activering van het lac-operon ........................................................................ 83
10.3 het tryptofaan operon ..................................................................................................... 84
repressie ..................................................................................................... 84
Attenuatie ................................................................................................... 84
Hoofdstuk 11: transcriptie regeling bij eukaryoten ................................................................. 86
11.1 organisatie van het genoom bij eukaryoten ................................................................. 86
Organisatie van nucleosomen ........................................................................................ 86
Hogere organisatie van chromatine ................................................................................. 87
Transcriptie regeling hangt samen met structuur van chromatine .................... 88
11.2: epi-genetische controle ................................................................................................. 88
Genomic imprinting ........................................................................................................ 89
11.3 transcriptie regeling ........................................................................................................ 90
Enhancers...................................................................................................................... 90
Transcriptie factoren ...................................................................................................... 90
Helix – turn – helix ........................................................................................ 90
Homeodomein............................................................................................. 90
Zink vingers ................................................................................................. 91
Leucine-zipper ............................................................................................. 92
Algemene kenmerken van DNA-bindende domeinen ...................................... 92
Hoe kunnen transactivatiedomeinen de transcriptie van een gen beïnvloeden? 93
Activatiedomeinen zijn eiwit-bindingplaatsen (histonmodificaties) .............. 93
Chromatine remodelling (volgt op de histonmodificaties) ............................ 93
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