The phrase central dogma refers to the usual flow of genetic information in a cell, in which DNA is transcribed into mRNA, which is subsequently translated into proteins by ribosomes.

• This chapter will go over transcription and translation processes and how they differ or are similar in prokaryotes and eukaryotes.

The process by which genetic information in a sequence of DNA nucleotides is transcribed into freshly generated RNA molecules is known as transcription.

• The enzyme RNA polymerase converts a DNA sequence into RNA molecules.

• The structure and sequencing of an RNA molecule determine its function:

• mRNA (messenger RNA) is a single-stranded RNA that transports information from the DNA to the ribosome.

Codons are three base-pair sequences in mRNA that are complementary to the DNA base pair sequence.

• During translation, these codons will identify certain amino acids.

• During translation, tRNA (transfer RNA) folds into a three-dimensional structure that functions as an adaptor molecule.

The one end of the tRNA will bind to a specific amino acid, while the other end includes an anticodon that will link with the proper mRNA codon at the ribosome during translation.

• Ribosomal RNA (rRNA) folds into a three-dimensional structure as well.

• Ribosomes, which are made up of rRNA and proteins, are responsible for the translation.

• The three-dimensional rRNA functions as a ribozyme, catalyzing the translational events.

Transcription in music refers to the arranging of a piece of music for various instruments. Consider transcription in biology.

• Consider transcription in biology to be the arranging of genetic information's "song."

• To begin transcription, the enzyme RNA polymerase must connect to a promoter, which is a noncoding DNA sequence.

The promoter sequence does not code for any amino acids, but rather serves as a binding site for RNA polymerase upstream from the start of a gene's coding region.

In living species, promoter sequences are extremely conserved.

• TATA boxes are found in most eukaryotic promoters because they are high in thymine and adenine nucleotides.

• Transcription factors are proteins that aid RNA polymerase in binding to the promoter region and initiating transcription.

• RNA polymerase, like DNA polymerase, adds new RNA nucleotides in the 5′ to 3′ direction during transcription.

RNA polymerase adds new RNA nucleotides in the 5′ to 3′ direction during transcription, similar to how DNA polymerase adds new DNA nucleotides in the 5′ to 3′ direction during DNA replication.

• The template strand is the strand of DNA that is being transcribed by RNA polymerase.

• Because the freshly manufactured RNA must be orthogonal to the template DNA strand, RNA polymerase reads the template DNA strand from 3′ to 5′.

• The base pair sequence of the transcribed RNA strand is complementary to the template DNA sequence.

• For instance, if the DNA sequence is 3′ – ACG TAC GTA CGT – 5′, the newly synthesized.

• Keep in mind that one distinction between prokaryotic and eukaryotic cells is that bacterial cells lack a nucleus.

• As a result, the mRNA transcript generated during transcription is readily accessible to ribosomes and may be translated without delay in most prokaryotic organisms.

The first mRNA transcript, known as pre-mRNA, in eukaryotic cells must be changed before it can leave the nucleus and travel to the ribosomes for translation.

• Before pre-mRNA may exit the nucleus in eukaryotic cells, three changes must occur: the removal of introns and the joining of exons, the attachment of guanosine triphosphate (GTP) cap to the 5′ end of the RNA, and the addition of a poly-adenine (poly-A) tail to the 3′ end.

• Introns are non-coding RNA segments found in eukaryotic pre-mRNAs.

• These introns are sandwiched between exons, which are coding regions of eukaryotic RNAs.

• Spliceosomes are structures consisting of small nuclear RNAs (snRNAs) and small nuclear ribonucleoproteins (snRNPs) that remove introns from pre-mRNA and then splice together the exons.

• These exons can be linked in various ways to produce numerous RNA transcripts from the same gene.

• The poly-enzyme A polymerase attaches an adenine nucleotide string to the 3′ end of the pre-mRNA transcript.

This 3′ poly-A tail aids in the prevention of transcript degradation.

• Longer 3′ poly-A tail mRNAs have longer cytosolic lifetimes, allowing for more copies of the protein (for which the mRNA codes) to be produced.

• Once the peptide bond between the amino acids is established, the first tRNA releases its amino acid (which is now connected to the second amino acid), and the ribosome releases the first tRNA.

Elongation refers to the movement of the ribosome and the insertion of additional amino acids to the polypeptide chain.

• In organisms, DNA and RNA are the bearers of genetic information.

  • In most species, genetic information begins with DNA, which contains the instructions for mRNA transcription.

  • The information about the sequence of amino acids in a protein is then provided by mRNA.

The genetic information in DNA is translated into mRNA in the nucleus of eukaryotes.

• The information in mRNA is used by ribosomes on the rough endoplasmic reticulum to translate proteins.

• A vesicle carrying the protein will bud out from the rough endoplasmic reticulum and go to the Golgi.

• The proteins will be changed and bundled into vesicles for cell export at the Golgi.

• These vesicles will leave the Golgi and proceed to the cell membrane. Vesicles

The vesicles subsequently merge with the cell membrane, releasing their protein contents.

• So, in a eukaryotic cell, the transfer of genetic information is as follows:

• DNA mRNA protein at ribosomes on the rough endoplasmic reticulum protein in vesicle protein outside the cell membrane.

• Some viruses employ RNA as their major genetic information carrier.

• These retroviruses include the reverse transcriptase enzyme.

Reverse transcriptase creates a DNA duplicate of the virus's RNA genome.

• This DNA copy is subsequently introduced into the genome of the virus-infected host cell.

• The information in the viral DNA incorporated into the host cell's genome will subsequently be transcribed and translated by the host cell.

• Because reverse transcriptase is less precise than RNA polymerase, retroviruses have a high mutation rate.