Polly polymerizes a 5-3 and reads at 3-5. Cannot start without an RNA primer, Aunt Polly can only elongate. Needs her friend Aunt Primase in order to do that.
WHAT ARE THE DIFFERENCES BETWEEN TRANSLATION AND TRANSCRIPTION?
Exceptions to the Rules: Retroviruses make DNA from RNA using the reverse transcriptase enzyme
DNA orders a meat lovers pizza using the genetic code online. OPerator is mRNA takes the msg. The tRNA is the delivery boy.
What is TRANSCRIPTION
DNA language to RNA language with uracil; Main site to regulate gene expression for euk/pro
What is the key function for Transcription?
Amount of mRNA that gets transcribed controls how much protein there is.
What does Transcription look like in genetic code?
AAAA in DNA => leads to UUUU in RNA
Coding strand that has the same sequence as the transcript. Has Thyme. Time to make sense.
The non-coding strand that is actually being transcribed ie. teenage daughter; Is Complementary to the transcript or to the parent sense strand; Has Uracil
How is DNA transcribed?
5-3 is downstream & 3-5 is upstream
RNA language into creation of proteins
WHAT ARE THE KEY ELEMENTS OF PROKARYOTIC RNA TRANSCRIPTION?
Bacterial RNA Poly. is made of alpha and beta sub units. Is the key enzyme needed for fast elongation during transcription.
But, it cannot actually initiate transcription - it needs help from the sigma factor.
The sigma factor?
helps polymerase to find promoters. When they join and create a holoenzyme which initiates transcription.
scans along the chromosome like a robot until it recognizes the promoter than stops
Why can we cannot digest Cellulose vs Starch?
Humans are unable to digest cellulose due to the large numbers of β(1,4) glycosidic linkages. These cannot be cleaved by human amylases and pass though the GI tract undigested. NB: (1,6) linkages are present in starch (not cellulose) at branch points and are digestible.
How do Dna link?
Phosphodiester bonds link nucleotides in DNA and RNA; while peptidyl linkages are what link amino acids in protein.
(hr-RNA); pre-RNA before splicing in euk. transcription
What is the 5’ Cap?
Methylated guanine nucleotides stuck on the 5’ end for eukarylotic RNA transcription
What is the 3’ Poly A Tail
Made of 100s of adenine nucleotides; Important as it prevents digestion of the RNA, without it, the RNA is attacked by free floating exonucleases.
Where is the Ribosome factory?
At the nucleolus
Eukaryotic Transcription Factor
A likely effect of a eukaryotic transcription factor is increase the encounter rate of DNA with RNA polymerase. Transcription factors influence many processes in transcription including recruiting RNA polymerase, regulating transcription rate, and many others.
COMPARE DNA REPLICATION & RNA TRANSCRIPTION - Similarities
Template driven polymerization of nucleic acids; Complementary strands; Driving force of removal and eventual hydrolysis of pyrophosphate, with the existing chain acting as the nucleophile; Poly. occurs in the 5-3 direction
COMPARE DNA REPLICATION & RNA TRANSCRIPTION - Differences
RNA obviously does not require RNA primer, where DNA needs an RNA primer; RNA polymerase cannot proofread - lacks exonuclease activity
monocistronic: one gene = one protein; Results in many different kinds of mRNAs for different kinds of proteins
Polycistronic; Genes are related in function
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