Bio Unit 0,3a,3b
prokaryotes
no nucleus
eukaryotes
nucleus
eukaryotes
protists, fungi, plants, animals
secretory pathway
Rough ER makes proteins and sends them to golgi where golgi takes them and packages them and distributes them to another place in the cell or to the plasma membrane
endocytic pathway
material enters cell via phagocytosis, lysosomes meet up with material and engulf them acting as a cell stomach
E coli
major model organism for DNA replication, transcription and translation
gene
codes for a protein
hydroxyl present on 2nd carbon
RNA
No uracil in bonds
DNA
template strand
codes RNA in 5'-3' direction
coding strand
identical to RNA, is not transcribed
RNA polymerase in prokaryotes
transcribes RNA strand
RNTPs
building blcoks for RNA
Holoenzyme
made up of core enzymes and sigma factor
sigma factor
uses -10 and -35 box to bind to promoter and initiates transcription
hairpin loop
forms a loop causing holoenzyme to fall apart and is reffered to as the termination of prokaryotic transcription
chromatin
DNA + Protein packing
RNA polymerase 1
transcribes most of rRNA genes
RNA polymerase 2
transcribes most proteins coding genes such as mRNA that is then translated into proteins
RNA polymerase 3
Transcribes tRNA genes and other small RNAs
Initiation of eukaryotes
TBP (TATA binding protein) recognizes TATA box. TFIID alters helix shape allowing other materials to pile in forming intiation complex.
capping
addition of cap on 5' end
poly a tail
addition of adenesine on 3' end
splicing
spliceosomes form loops that remove introns
mutations of splicing (3)
1. loss of exons
2. shift in location of splice
3. introns left
exon junction complex
regulates exportation of nucleus