what happens in the stages of protein synthesis?

Answer 1

The first stage of protein synthesis is transcription. The DNA helix is untwisted by the enzyme dna helixase. Then the DNA is split into two as the hydrogen bonds are broken between the complementary base pairs. Then a mRNA strand is made with complementary pairs, much like with DNA replication. However this mRNA strand leaves the nucleus via the nuclear pores.
The second step of protein synthesis is translation, which occurs in the cytoplasm and requires ribosomes. A small ribosomal subunit attaches to the bottom of the mRNA strand, and a large ribosomal subunit to the top of the mRNA. Then the synthesis can begin. For it to start the first codon (base triplet) must be methionine (AUG.) Then the anticodons on a tRNA with an amino acid comes into the large ribosome unit and matches with a codon. The first anticodon must be (UAC) because it is complementary to AUG. Then the next anticodon comes along. Before the tRNA leaves the ribosome polmerase creates a peptide bond between the amino acids. Then the tRNA leaves the ribosome, leaving the amino acid behind. This process repeats itself until it reaches a stop codon. Then the amino acid chain (polypeptide) is released into the cytoplasm as a protein when the ribosome and mRNA separate. This protein is in its primary structure (the arrangement.) It can then assume its secondary structure (alpha helix or beta pleated sheet.) Then tertiary 3d precise shape (globular of fibrous.)

Answer 2

Protein Synthesis Flow Chart

Answer 3

In the first stage of protein synthesis, it produces mRNA from DNA in the nucleus. This stage of protein synthesis is called transcription. The creation of the mRNA or the messenger RNA involves unwinding the DNA helix. Then, 1 side of the DNA is used to help create the new mRNA. The mRNA seperates itself from the DNA and exits the nucleus. It then moves to the cytoplasm in the cell.
The second stage of protein synthesis occurs in the cytoplasm while being attached to some ribosomes. This stage is called translation. The mRNA previously made is then translated into protein. The tRNA (or the transfer RNA) then brings a specific amino acid.

Answer 4

Steps Of Protein Synthesis

Answer 5

Somebody asked this a little while ago; I will repost my answer because it is thorough and well written. I know it is long, but if you really want to know, bear with me and read. The process is so very complex that it can't just be summarized up neatly like the answerer above me seems to think it can be.

Protien synthesis is an incredibly complex process that is most likely occuring inside of every cell of your body at this very minute; indeed such a general statement cannot be answered in full here, but I shall give such an overview as I am qualified to make. Protien synthesis begins when mRNA strands are transcribed in the nucleus. The strands are created along a DNA template strand using the help of RNA polymerase and an assortment of other enzymes. Nucleotide bases are attatched (G to C, G to C, A to T, T to A), to form these strands, and form a line of codons, groups of three bases that code for a specific amino acid. These strands, when complete, then undergo a series of modifications, where splicosomes cut out the excess, uncoding portions of the RNA strand, the introns, and glue together the remaining pieces to form an mRNA molecule out of the exons. After the 5' Cap and Poly-A Tail have been added to prevent the disintegration of the molecule in the cytoplasm, the mRNA enters the cytoplasm and finds a ribosome. The mRNA attatches to the ribosome, and tRNA molecules assemble a polypeptide chain along the strand. Each codon codes for an amino acid which is carried by the tRNA. When a tRNA docks in the active site, the carried amino acid will form a bond with the amino acid in the passive site, and gradually a chain is formed. Polypeptide chains are the forerunners of protiens; they are called the primary structure. The secondary structure occurs when the chains form into either an alpha-helix or a beta-pleated sheet, where bonds among amino acids keep the chain in a specific shape. The tertiary structure occurs when a single polypetide chain creates a complex structure of both helixes and pleated sheets. Finally, the quaternary structure is formed when several tertiary chains congregate and form bonds, creating a single unit. Indeed, the process is long and complex, yet it occurs constantly and rapidly within our cells. Without protiens, our very existence would be impossible!

Answer 6

Transcription: In the nucleus, an RNA copy (mRNA transcript) of a gene is produced Translation : In the cytoplasm, ribosomes attach to the mRNA and move down it, translating 3 consecutive bases into a single amino acid, join the amino acids together into the protein molecule.

Answer 7

Steps in protein synthesis
1.Transcription
2.Translation

Transcription is the process by which an mRNA template, carrying the sequence of the protein, is produced for the translation step from the genome. Transcription makes the template from one strand of the DNA double helix, called the template strand. Transcription takes place in 3 stages.

1.Transcription starts with the process of initiation. RNA polymerase, the enzyme which produces RNA from a DNA template, binds to a specific region on DNA that designates the starting point of transcription. This binding region is called the promoter. As the RNA polymerase binds on to the promoter, the DNA strands are beginning to unwind.
2.The second process is elongation. RNA polymerase travels along the template (noncoding) strand, synthesizing a ribonucleotide polymer. RNA polymerase does not use the coding strand as a template because a copy of any strand produces a base sequence complementary to the strand which is being copied. Therefore DNA from the noncoding strand is used as a template to copy the coding strand.
3.The third stage is termination. As the polymerase reaches the termination stage, modifications are required for the newly transcribed mRNA to be able to travel to the other parts of the cell, including cytoplasm and endoplasmic reticulum for translation. A 5' cap is added to the mRNA to protect it from degradation. In eukaryotes, poly-A-polymerase adds a poly-A tail onto the 3’ end for stabilization, protection from cytoplasmic hydrolytic enzymes and as a template for further process. Also in eukaryotes (higher organisms) the vital process of splicing occurs at this stage by the spliceosome enzyme. It removes the introns (non-coding bits of genetic material) and glues together the exons (the segments that code for a specific protein).
4.The mRNA now exits the nuclear pore to be translated.

Translation(The process of synthesizing a protein from an mRNA template is known as translation)

Translation is the second process of protein biosynthesis (part of the overall process of gene expression).Translation occurs in the cytoplasm where the ribosomes are located. Ribosomes are made of a small and large subunit which surrounds the mRNA. In translation, messenger RNA (mRNA) is decoded to produce a specific polypeptide according to the rules specified by the genetic code. This is the process that converts an mRNA sequence into a chain of amino acids that form a protein. Translation is necessarily preceded by transcription. Translation proceeds in four phases: activation, initiation, elongation and termination (all describing the growth of the amino acid chain, or polypeptide that is the product of translation).

In activation, the correct amino acid (AA) is joined to the correct transfer RNA (tRNA). While this is not technically a step in translation, it is required for translation to proceed. The AA is joined by its carboxyl group to the 3' OH of the tRNA by an ester bond. When the tRNA has an amino acid linked to it, it is termed "charged". Initiation involves the small subunit of the ribosome binding to 5' end of mRNA with the help of initiation factors (IF), other proteins that assist the process. Elongation occurs when the next aminoacyl-tRNA (charged tRNA) in line binds to the ribosome along with GTP and an elongation factor. Termination of the polypeptide happens when the A site of the ribosome faces a stop (nonsense) codon (UAA, UAG, or UGA). When this happens, no tRNA can recognize it, but releasing factor can recognize nonsense codons and causes the release of the polypeptide chain. The capacity of disabling or inhibiting translation in protein biosynthesis is used by antibiotics such as: anisomycin, cycloheximide, chloramphenicol and tetracycline.

Answer 8

1. DNA polymerase splits the DNA into two strands.
2. mRNA makes a complimentary copy of the DNA
3. The mRNA breaks off from the DNA and finds a ribosome.
4. The ribosome "reads" the mRNA and tRNA brings the correct amino acid that is coded.
5. The ribosome attaches the amino acids to form a long protein chain