Euk & Pro Replication

krabi's version from 2015-07-25 01:43

Section 1

Question Answer
How does eukaryotic DNA replicate?Linear - Has multiple replication bubbles and origins of replication
Where does Euk. DNA replicate?ALL: replication, transcription and splicing all occur in the nucleus
What extra cell bodies do Euks have? Mitochondria with its own transcription & translation
How do prokaryotic bacteria replicate?circular Theta replication + Only 1 point of origin + Only 1 chromosome
Where does PROK. DNA replicate?Transcription & translation occurs in the cytoplasm
What key enzymes do prokaryotics have?DNA polymerase
3 kinds of pro.replication DNA Polymerase?POLYMERASE 1, 2, 3
POlymerase 1DNA Pol I: 5 - 3 exonuclease to remove RNA primers - slowpoke
POlymerase 2DNA Pol II: n/a
POlymerase 3DNA Pol III: Fast proofreader Fast 5 - 3 exonuclease to remove RNA primers
Key DNA replication saying Aunt Poly reads at 35, proofreads at 53
How is DNA chemically replicated?The hydrolysis of the pyrophosphate is part of the coupled rx that theormodynamically drives DNA replication.

Section 2

Question Answer
What are Replication Rules?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.
Question Answer
What is TRANSCRIPTIONDNA 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
SENSE STRANDCoding strand that has the same sequence as the transcript. Has Thyme. Time to make sense.
ANTI-SENSE STRANDThe 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
TRANSLATIONRNA 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.
Question Answer
The sigma factor? helps polymerase to find promoters. When they join and create a holoenzyme which initiates transcription.
The holoenzyme? 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.

Section 2

Question Answer
Heterogenous RNA(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 TailMade 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 FactorA 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 - SimilaritiesTemplate 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 - DifferencesRNA obviously does not require RNA primer, where DNA needs an RNA primer; RNA polymerase cannot proofread - lacks exonuclease activity
EUKARYOTIC mRNA?monocistronic: one gene = one protein; Results in many different kinds of mRNAs for different kinds of proteins
Bacterial mRNA?Polycistronic; Genes are related in function