Making Proteins
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On this lab you’ll find out how residing cells produce proteins. Protein synthesis requires two distinct processes, transcription and translation. You should have a possibility to evaluation each procedures as you “make a protein.” You’ll use your textbook and the data on this lab as a reference.
Half 1: Transcription and Translation Assessment[1]
Introduction
As you realize, DNA is a really lengthy, skinny molecule fabricated from proteins and nucleotides. The DNA in a single chromosome has 10s of thousands and thousands of base pairs and a whole lot or 1000’s of genes that code for quite a lot of totally different proteins. Nonetheless a person cell will solely use a small portion of these genes in its lifetime. Think about a mechanic who spends a lifetime fixing nothing however automobiles, however she or he is required nonetheless to hold round a complete library of restore manuals for all the pieces from kitchen sinks to washing machines to lighting fixtures to computer systems and so forth!
Now think about the situation of Eukaryotic DNA. Eukaryotic organisms defend their DNA by storing it contained in the nucleus. Nonetheless, the protein making factories (ribosomes) are situated within the cytoplasm exterior of the nucleus. How does the cell remedy this drawback? It should ship a “messenger” that carries a replica of the genetic data from the nucleus to the ribosomes within the cytoplasm.
Protein synthesis is a two-step course of that entails two important occasions referred to as transcription and translation.
In transcription, the DNA code is transcribed (copied) into mRNA. As soon as the mRNA is produced it strikes out of the nucleus into the cytoplasm the place it hyperlinks up with ribosomes (protein making organelles) and begins churning out proteins. Earlier than taking a look at translations let’s take a more in-depth take a look at transcription.
Recall that DNA consists of a sugar-phosphate spine with a nitrogenous base. There are 4 totally different bases in DNA abbreviated with the letters A,T,C, & G. The code contained in DNA derives from these 4 bases. We are able to consider them as letters in an alphabet that can spell totally different phrases.
In DNA code, a “word” is at all times 3 letters lengthy and it specifies one in all 20 amino acids. Nonetheless, DNA isn’t straight concerned within the translation course of, as an alternative mRNA is transcribed right into a sequence of amino acids. When studying the mRNA, it’s “read” in a sequence of three adjoining nucleotides.
In transcription, the DNA code is transcribed (copied) into RNA code, following guidelines just like DNA replication we noticed earlier besides that Thymine (T) is changed by Uracil (U).
Lab Questions
Transcription leads to the formation of an mRNA molecule that carries the directions for the precise protein to the ribosome the place the data is “translated” right into a sequence of amino acids to type a protein.
Now let’s take a look at the method of translation. Translation requires the directions required to make the protein (mRNA), the required amino acids, and the ribosome (rRNA). Every mRNA codon corresponds to an amino acid that’s transported to the RNA/ribosome advanced by one other particular nucleic acid referred to as tRNA. “T” stands for switch. The ribosome primarily “reads” the RNA code and facilitates the linking of applicable amino acids to make proteins.
Abstract
Exercise
There are solely 4 letters within the mRNA code: U-A-C-G. What number of doable combos are there? In different phrases, what number of “words” are you able to make with these 4 letters if any mixture of letters is feasible however all “words” are solely 3 letters lengthy? There are 64 doable combos but, there are solely 20 amino acids (see the corresponding Genetic Code desk in your Lab 6 homework. What does this imply concerning the how every amino acid is “spelled”? You have to to look this up.
Half 2: Transcription and Translation in Motion
Now that you’ve examine transcription and translation, let’s see in case you can translate and transcribe a gene. Please go to the College of Utah Genetics web site and full the exercise entitled Transcribing and Translating a Gene.
Lab Questions
You have to to stick a display shot of the finished exercise in your homework.
– “protein synthesis lab”
“protein synthesis lab”