Chromosomes and DNA Flashcards
Basal Transcription
low level of Transcription
DNA polymerase
Enzyme, synthesizes new DNA in 5’–>3’ direction + proofreads it
Transcription
Process of expressing DNA in RNA (in Nucleus)
Nucleoside
Sugar+Base
Transcriptionfactors
Factors that regulate Transcription
Chromatin
Components of DNA (a-Helix structure + Proteins)
lariat-structure
Formation of Intron, in which the Splice Donor Site binds to an A in the MRN and forms loop –> ,,lariat” (Lasso)
RNA Processing
Process to form mRNA from preRNA by cutting off the Introns and adding a CAP- structure and a polyA tail
DNA primase
Synthesises RNA primer
Interphase DNA
30nm fibre folded into loops
RNA repair DNA polymerase
Turns RNA Primer into DNA
RNA-polymerase 3
Transcribes tRNA + 5SRNA genes
DNA ligase
Links Okazaki fragments
Replication fork
“bubble” where DNA replication takes place
alternative Splicing
Cutting out of eg. mutations in Exons and thereby mimimization of damage to protein
Nucleosome
Stage of Packed DNA consisting of Histones and ca. 11nm wide
Splice Donor Site
Site at Begining of an Intron, Starts with Sequence GU
30nm fibre
6 Nucleosomes next to each other stacked together, 30nm wide, 40 fold condensatin
Translation
Process of eypressing RNA into Aminoacidsequence (Protein) in Cytoplasm
RNA-polymerase 1
Transcribes rRNA genes
Leading strand
Leitstrang, DNA strand which can be duplicated with only one Primer needed (5’–>3’ direction)
Splice Aceptor Site
Site at End of Intron, Sequence almost always Pyr15NCGA
RNA-polymerase 2
Transcribes mRNAn!!!!
Bidirektional replication
Replication takes places in two directions and many replication forks simmutaniously so replication is faster
CAP structure
Structure wich is added at the begining of mRNA 5’ End as recognitionof mRNA –> important for Translation and protection of mRNA
mRNA
mRNA Template for translation (formed during transcription)
Gene expression
Process of “using” a gene
Lagging Strand
Folgestrang, DNA strand which needs several primers to complete replication (3’–>5’ direction)
tRNA
transfer RNA, brings Aminoacids to form Protein
Antisense strand
DNA strand that is template for RNA formation (3’–>5’)
Sliding Clamp
Protein that holds DNA polymerase on DNA for synthesis
Nucleotide
Phosphate+Sugar+Base
Spliceosome
Splicing Complex (snRNAP + Intron+Exon)
DNA helicase
Separates DNA Strands for replication by using ATP
pre-RNA
RNA which still needs to undergo RNA Processing to become RNA
Ribosomal RNA
exists
polyA tail
Tail of Adenines which es beeing added at End of mRNA 3’ to protect RNA
11-30 Bases after AAUAAA sequence
sense Strand
DNA stand that equals expressed RNA strand (5’–>3’)
Non-coding RNAs
Any RNA molecule that is not translated into protein
Functional housekeeping RNA
target DNA
DNA which should be replicated (in Cell based Cloning)
DNA which should be analysed (In NA hybidisation)
replicon
DNA Sequence which is capable of indipendent replication (e.g. bacteria plasmid) and is beeing used in Cell based Cloning
Restriction Endonuclease
Specific Enzyme which cuts target DNA and replicon (with compatible ends)
Recognises specific Base Pair sequences
Blunt Ends
When Ribunuclease cuts straigth to two base pairs:
AC TG
TG AC
Sticky Ends
When Endonuclease cuts not evenly throuhg Bases:
AGC T
TC GA
Seperation of DNA by Electrophoresis
DNA phosphate backbone is negatively charged
When current applied travels to + ENd
The smaller the DNA sequences, the further they travel
PCR (+Key processes)
Polymerase Chain Reaction
Denaturation (94°)
Annealing (50-60°)
Extending (72°)
Primers in PCR
- 20 NT –> specific
equal Tm to DNA
avoid complementary 5’, 3’ Ends
Hybridisation Stringency
Accurancy with which complementary base paris bind to each other
High = one to one match
Low = Some mismatched occur
Higher with higher Temperatures and Lower Salt concentrations
Nucleid Acid Hybridisation
Target DNA immobisised on statinary
Marked probe DNA added + binds to complementary strand
pre-initiation complex
Complex formed by tRNA (+Met), ribosomal subunit, GTP, elF2
Peptidyl transferase
Enzyme that catalysis peptide bond formation
Elongation factors (ELF)
Promote movement of ribosome with use of GTP
What is needed for PCR?
DNA
2 RNA primers
Taq (or heat stable) DNA polymerase
Nucleotides
What are possible post translational modifications?
Proteolytic cleavage
Disulphide bond formation
Addition of carbohydrate (Glycosylation)
Addition of phosphate (Phosphorylation)
Addition of lipid groups (Acylation, Prenylation)
