Protein Synthesis and Transcription

Transcription is the formation of an RNA strand from a DNA template within the nucleus of a cell. There are four nucleotides of DNA. These are adenine, cytosine, guanine and thymine. These nucleotides are transcribed to form messenger ribonucleic acid (mRNA) consisting of nucleotides made of adenine, cytosine, guanine and uracil. This transcription from DNA to mRNA happens by an RNA polymerase II. This newly created mRNA is read in the 5' to 3' direction in sets of 3. These sets are called codons. Each mRNA also has a cap and end. On the 5 prime side is a methylated guanine triphosphate and on the 3 prime is a poly A tail. Messenger RNA then moves to the cells cytoplasm and through the cells ribosomes for translation. Messenger RNA is matched to molecules of transfer RNA (tRNA) in the ribosomes to create amino acids. These amino acids subsequently form an amino acid chain. (Osuri, 2003) A visual representation of this can been viewed in figure 3.

3) As a ribosome moves along the mRNA, the genetic message is translated into a protein with a specific amino acid sequence.

After the DNA has been turned into mRNA a process called translation occurs and it turns the mRNA into tRNA.

Translation is a task that makes ribosomes synthesize proteins utilizing mRNA transcript made during transcription. In the begining of this task mRNA attaches it self to a ribosome so that it can be reveal a codon (three nucleotides).

Transcription is a process in which genetic information from DNA is encoded onto messenger RNA, by unwinding the DNA and splicing exons and introns and coding them onto the mRNA so the DNA itself is not used directly. Translation is a process by which ribosomes reads the mRNA to determine the amino acid sequence of the protein.

Proteins are primarily considered to have one primary function to serve its role in an organism, however studies have observed to have multiple functioning proteins known as moonlighting proteins (Khan et al. 2014). Moonlighting proteins along with primary functions, have secondary functions that are not related to the primary function and does not correlate to the primary or other functions (Khan et al. 2014). The multifunctional proteins play essential roles in carrying out biochemical functions which aids in the cell growth but are not caused by gene fusion and multiple RNA splice variants (Amblee et al. 2015). The discovery of moonlighting proteins was first discovered by Piatigorsky and Wistow while observing crystallins (Khan et al. 2014). Crystallins, are structural proteins that are found in the eye lens that exhibit enzymatic activity to make the lens itself (Khan et al. 2014). Crystallin has a primary function to help form the lens of the eye by acting as a structural protein (Amblee et al. 2015). Besides enzymatic activity, crystallin was observed in other mammals to have secondary functions such as metabolic functions which are helpful in prokaryotic (Khan et al 2014). Most moonlighting proteins are characterized as cytosolic enzymes and chaperons, or in other words helping proteins (Amblee et al 2015). The multifunctional proteins or moonlighting proteins can also be identified as receptors, channel proteins and ribosomal proteins (Khan et al. 2014). Due to the

translation begins with the reading of the first triplet. Small tRNA molecules bring in the

Protein synthesis is a two-part process that involves a second type of nucleic acid along with DNA. This second type of nucleic acid is RNA, ribonucleic acid.

1) Watson and Crick: Used Rosalind Franklin’s x-rays of DNA to conclude that DNA took the shape of a double helix.

At the end of this unit, students will be able to use the terms DNA, RNA, protein, and nucleotide when it comes to protein synthesis. They will be able to explain how transcription and translation are processes of protein synthesis. They will be able to use genetic code table to translate an RNA sequence into an amino acid sequence. Students will be able to demonstrate their understanding of the Central Dogma. They will be able to describe the semi-conservative nature of DNA replication. They will be able to explain how a change in the DNA sequence code can alter protein function.

The flow of information from DNA to RNA to proteins is one of the fundamental principles of molecular biology. It is so important that it is sometimes called the “central

One of the fundamental discoveries of the 20th century was that DNA was the genetic code’s physical structure (Watson & Crick, 1953) and, since then, many studies have disclosed the complicated pattern of regulation and expression of genes, which involve RNA synthesis and its subsequent translation into proteins.

Transcription is where DNA is transcribed into RNA which then can be pass to the ribosome’s to act as a template for protein synthesis. Before transcription can begin DNA must unwind and the two halves of the molecule much come apart so exposing the base sequence. This process begins when a region of a two DNA strands is unzipped by enzyme called RNA polymerase attaches to the DNA molecule at the imitation site.

The major research questions addressed in the presentation consisted of: why to study microbes? , What are the basics of gene expression? , What’s special about riboswitches? The major hypotheses that were explored during the presentation were “S box” represses genes involved in the synthesis of methionine and SAM in response to the high SAM concentration; and the low SAM results in the readthrough of the termination site. Also “How can gene expression be regulated” and under what conditions/processes the bacterial cells could use to detect environmental signals, specifically Dr. Henkin talks about some of the predictions of the model, which another hypothesis is “If we reduce SAM concentrations in the cell would we see increased gene expression”? Also would the increase in expression be from the effects on translation? Dr. Henkin used a variety of the methods to study the topic including a power point presentation in which she organized the information she was going to talk about in front of the class. The specific method used in the presentation was the S box riboswitch structural model, and the different types of S box riboswitches. (SAM). She started the presentation talking about how bacterial cells have more genetic information than they use at any given time, and explained the basics of gene expression. Dr. Henkin explained the many important steps that the expression undergoes. Starting with step 1, transcription occurs which is the expression of a gene requiring the

Protein synthesis is one of the most fundamental biological processes. To start off, a protein is made in a ribosome. There are many cellular mechanisms involved with protein synthesis. Before the process of protein synthesis can be described, a person must know what proteins are made out of. There are four basic levels of protein organization. The first is primary structure, followed by secondary structure, then tertiary structure, and the last level is quaternary structure. Once someone understands the makeup of a protein, they can then begin to learn how elements can combine and go from genes to protein. There are two main processes that occur during protein synthesis, or peptide formation. One is transcription and