RNA polymerase is the main protein that creates the RNA transcript
Proteins called transcription factors help RNA polymerase and regulate it's function.
2 types of transcription factors: basal tfs and modulatory tfs.
Basal transcription factors - required for all transcription events.
Modulatory transcription factors - regulate expression of genes. Both positive and negative regulation.
Transcription factors can act from relatively far away. Up to 10kb!
pre-mRNA transcripts are spliced to remove exons.
Alternative splicing allows the cell to combine exons differently in the final mRNA transcript from the same pre-mRNA transcript.
Transcription in five easy steps
Transcription of DNA to pre-mRNA. DNA, RNA polymerase and transcription factors.
Addition of 5' methyl guanosine cap to pre-mRNA transcript.
Splicing of pre-mRNA transcript (yields mRNA proper)
Addition of 3' poly(A) tail to mRNA transcript.
mRNA is transported to the cytoplasm.
5 steps of mrna preparation
Rna polymerase - main protein that creates rna transcript.
RNA polynmerase is the protein whose job it is to 'read' the genetic code and create a complimentary RNA transcript from that code. Eukaryotes have three different types of RNA polymerases: RNA polymerase I, II, and III. RNA polymerase II is the from of polymerase that transcribes most genes and is the form of polymerase with which we need to concern ourselves.
Initiation of transcription
Transcription initiation in eukaryotes is complicated, and the details are not entirely understood (although we do have a good grasp on the basic mechanism). The fully assembled eukaryotic transcription inititation complex contains more than 50 polypeptides. RNA polymerase II has more than 10 polypeptide subunits by itself. Keep in mind that the process outlined below is a generalization, and any given, specific transcription event will probably vary some in the details. For example, although the TATA box is the most strongly conserved promoter sequence, it is by no means present in every eukaryotic promoter. Also, there is some debate as the importance of the order of the binding of the proteins in the initiation complex: it was thought that a specific order was vital, now, however, new evidence suggests that reaching the end binding state may be what is really important, whatever the order.
Transcription factors - help/regulate rna polymerase's function
Transcription factors (tfs) are proteins involved with transcription - except for RNA polymerase. Transcription factors can be broken down into two groups: basal tfs and modulatory tfs. Eukaryotic RNA polymerases are not capable of initiating transcription alone, they require the assistance of a set of basal transcription factors. Basal tfs assist RNA polymerase in the recognition of promoter sequences and unwiding the DNA double helix, among other functions. Basal tfs are necessary for every transcription event. Modulatory transcription factors regulate the expression of a gene, or a set of gene. These tfs are important because they allow the body to differentially express genes at different times and different places in the body. Modulatory tfs are vital for multicellular life. They allow the body to create different cells, tissues, and organs.
Bacteria doesn't produce energy they are dependent upon their substrate in case of lack of nutrients they are able to make spores which helps them to sustain in harsh environments
_Adnan
But not all bacteria make spores, l mean Eukaryotic cells have Mitochondria which acts as powerhouse for them, since bacteria don't have it, what is the substitution for it?
Assimilatory nitrate reduction is a process that occurs in some microorganisms, such as bacteria and archaea, in which nitrate (NO3-) is reduced to nitrite (NO2-), and then further reduced to ammonia (NH3).
Elkana
This process is called assimilatory nitrate reduction because the nitrogen that is produced is incorporated in the cells of microorganisms where it can be used in the synthesis of amino acids and other nitrogen products
There are nothing like emergency disease but there are some common medical emergency which can occur simultaneously like Bleeding,heart attack,Breathing difficulties,severe pain heart stock.Hope you will get my point .Have a nice day ❣️
_Adnan
define infection ,prevention and control
Innocent
I think infection prevention and control is the avoidance of all things we do that gives out break of infections and promotion of health practices that promote life
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Source:
OpenStax, Statistical machine learning for computational biology. OpenStax CNX. Oct 14, 2007 Download for free at http://cnx.org/content/col10455/1.2
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