This sample essay on Protein Synthesis Essay offers an extensive list of facts and arguments related to it. The essay’s introduction, body paragraphs, and the conclusion are provided below.
In order to understand 1) protein synthesis, or the production of proteins, it is important to understand RNA and how it is transcribed from DNA. And in order to understand 2) transcription, or the process by which genetic information is copied from DNA to RNA, it is important to understand both the structure and replication of DNA, which is the source of the genetic information that tells cells which proteins to make and when to make them.
A DNA molecule is made up of two long chains of nucleotides, which are the basic structural units of nucleic acids.
One nucleotide consists of three parts: a sugar molecule, called 3) deoxyribose, a phosphate group, and a 4) nitrogen-containing base. The two nucleotides are covalently bonded together between the deoxyribose and phosphate molecules. A key concept to also understand is that there are four kinds of nitrogen-containing bases.
This is important because they bond with each other by means of hydrogen bonds in a way that forms the 5) double helix shape of DNA and the way they pair led to suggestions of how DNA copies itself.
The four kinds of nitrogen-containing bases are 6) adenine, 7) guanine, 8) cytosine, and 9) thymine. 10) Base-pairing rules are two rules that describe how these bases: they state that cytosine bonds with guanine and adenine bonds with thymine. These two pairs of bases are known as 11) complementary base pairs.
Because protein synthesis requires RNA, and RNA comes from DNA, there must be enough DNA to produce RNA. The process in which DNA is copied is called 12) replication. Replication occurs when the two nucleotide chains of DNA separate by unwinding, and each chain serves as a template for a new chain.
During replication, enzymes called 13) helicases separate DNA’s two chains of nucleotides at the 14) replication fork. Other enzymes, called 15) DNA polymerases, bind to the separated chains, and one at a time construct a new complementary chain of nucleotides based on the sequence of the nitrogen-containing bases. When replication is completed, there are two new exact copies of the original DNA molecule, both of which consist of one new nucleotide chain and bonded to a nucleotide chain from the original DNA.
On the off chance that there is a slight change in the nucleotide sequence, which is known as a 16) mutation, a cell may have serious effects. The DNA may be damaged, and it would not produce the correct RNA, which would then cause a production of incorrect proteins, or a deficiency of proteins that are needed. However, the number of errors and mutations in DNA replication is reduced proofreading and repairing by certain enzymes. In eukaryotes, the genes directing protein production are in the nucleus, but the building blocks for enzymes and amino acids are located in the cytosol.
Ribonucleic acid, or RNA, is responsible for the movement of genetic information from the DNA in the nucleus to the cytosol where protein synthesis occurs. RNA, like DNA, is composed of repeating nucleotides. However, RNA is structurally different from DNA in a few ways. Instead of the sugar molecule a molecule being deoxyribose like it is in DNA, the sugar molecule of RNA is just 17) ribose. Another difference between DNA and RNA is their nitrogen-containing bases. DNA has thymine, but RNA has 18) uracil instead of thymine.
A third difference between DNA and RNA is that some forms of RNA are made up of a single nucleotide chain, whereas every DNA molecule consists of two chains of nucleotides. RNA exists in three types: 19) messenger RNA (mRNA), which carries genetic information from the DNA to the cytosol, 20) transfer RNA (tRNA), which binds to certain amino acids, and 21) ribosomal RNA (rRNA), which makes up the ribosomes where proteins are made. RNA must carry the genetic information from DNA to the cytosol through transcription. During transcription, an enzyme called 22) RNA polymerase binds to the 23) promoter of a gene.
The promoter marks the beginning of the DNA chain to be transcribed. Then, a complementary copy of that gene’s DNA base sequence is made using RNA nucleotides, thus forming the mRNA. Transcription continues as the RNA polymerase continues adding complementary RNA nucleotides until it reaches the 24) termination signal, where the RNA polymerase releases both the DNA and the new RNA. The transcripts that are produced from transcription are the three types of RNA, all of which are involved in protein synthesis. In protein synthesis, the nucleotide sequence of an mRNA molecule is ranslated into a sequence of amino acids using the 25) genetic code, which correlates between a nucleotide sequence and an amino acid sequence.
The genetic information needed to make proteins is encoded in a series of three mRNA nucleotides; each of which is called a 26) codon that codes for a specific amino acid. The 27) start codon and the 28) stop codons, however do not code for specific amino acids. The start codon, AUG, engages a ribosome to start translating an mRNA molecule, and the stop codons cause the ribosome to stop translating an mRNA. 9) Translation, which is the process of assembling polypeptides from information encoded in mRNA, begins when the mRNA exits the nucleus through nuclear pores and migrates to a ribosome in the cytosol. The tRNA molecule transports freely floating amino acids to the ribosomes and adds a specific amino acid to the polypeptide chain as each codon is sequentially paired with its 30) anticodon, a region of tRNA that consists of three bases complementary to the codon of mRNA. The assembly of a polypeptide starts when a ribosome attaches to AUG, the start codon on an mRNA transcript.
The pairing of an anticodon with a codon causes the specified amino acid to attach to the previously translated amino acid, and therefore create a growing polypeptide chain. When the ribosome reaches a stop codon, translation is brought to an end and the mRNA is released from the ribosome and the polypeptide is complete. Protein synthesis is important because through carrying out the genetic information encoded in an organism’s DNA, the amount and kind of proteins that are produced in a cell determine the cell’s structure and function.