REPLICATION OF DNA AND PROTEIN SYNTHESIS Flashcards
In prokaryotes, transcription occurs in only one direction and begins at only one point
replication
In eukaryotes, transcription occurs in both directions and at more than one point and occurs in the nucleus
replication
A duplicating mechanism involves disengaging the DNA strand (polynucleotide) by loosening the weak hydrogen bonds
replication
Serves to loosen the twin screw, separating the two straps , separating each other and converting DNA into a single strand by breaking the hydrogen bonds
helicase
DNA is replicated in opposite directions. That is, the backing thorns move in opposite directions ‘Bidirectional replication’ .
mechanism of DNA replication
Semi-continuous DNA replication, one strand is copied continuously, while the other lagging strand is copied in the form of pieces called Okazaki fragments.
mechanism of DNA replication
Polymerization only occurs in the direction of 5 to 3
mechanism of DNA replication
DNA Topoisomerases , DNA polymerase , Helicase , Primase , DNA ligase .
the enzymes that work on replication of DNA
Connects the Okazaki fragments
DNA ligase
RNA is made to initiate, because the polymerase enzyme does not work in the direction of 3 - 5, so this tape is constructed in the form of small pieces in the direction of 5 - 3 by the enzyme polymerase and then these small pieces are linked together by the binding enzyme - Ligase DNA
Primase
It extends the length of the thread but cannot start forming a new thread, and it only works in one direction 5 to 3.
DNA polymerase
The most important enzyme in this process (loading of nitrogenous bases) is the enzyme for DNA polymerase (DNA). The role of this enzyme is to clone a complementary or complementary strand of parental DNA. The first one acts as a template, thereby creating two daughter strands.
DNA polymerase
It works to convert DNA into a single strand by breaking down the hydrogen bonds.
Helicase
Decodes supercoiling in DNA.
DNA Topoisomerases
Most of the protein synthesis occurs in the cytoplasm, but the protein’s genetic code is in the nucleus
Its size does not allow it to leave the nucleus, so a small copy of it is taken in m-RNA because the DNA
Which can leave the nucleus through the openings of the nucleus into the cytoplasm.
Transcription
The transcription is made from one strand of DNA and this strand is called
anti-coding strand
A thread from which it is not copied is called
non coding strand)
Transcription is done by a special enzyme called
RNA polymerase
Promotor region , transcribed region , termination region
contents of Transcription Unit
Transcription Unit , Four ribonucleotide triphosphate , RNA polymerase .
the three requirements to transcript the RNA
ATP, GTP,CTP,UTP
Four ribonucleotide triphosphate
Initiation , elongation , termination
the three stages of the transcription
Linking RNA Polymerase to the Promoter region, to decode the DNA loop and made the primer, and the first nucleotide at the priming site is always purine
initiation
Polymerase catalyses the lengthening process of the RNA chain to elongate 5 to 3
elongation
Once RNA Polymerase identifies a specific nucleotide chain that indicates the end of the synthesis and completion of the transcription process.
termination
replication —- transcription —- translation —- protein
protein synthesis
they are large molecules made of amino acids , It is usually made up of 20 or more amino acids
protein
Genetically, it means converting the language of nucleotides into an amino acid language , The final stage of transfer of protein synthesis information takes place on Ribosomes and requires tRNA and mRNA , Ribosomes are free in the cytoplasm and associated with the xylem endoplasmic reticulum , It consists of two units, large and small, and each unit consists of rRNA and enzymes joined by the large unit, and the ribosomes start to read the code on m-RNA , The AUG start codon has the m-RNA start codon , There is a specific tRNA for each amino acid, which is estimated at 20 amino acids , so all proteins start with it at the very beginning, and after the protein chain synthesis process is finished, it may remain or be removed
translation
They occur on Ribosomes, and rRNA is composed of enzymes , Requires tRNA to carry homocysteine and have an anticodon , mRNA is known as a messenger and bears a genetic code ,
translation
Except for the mRNA stopping codes, a special code on tRNA has to be each
translation
Translation occurs continuously as the codes are read on the messenger RNA and in the same breath
translation
Time the amino acids are linked to form a chain starting, for example a small unit
translation
Carrying the ACC, the ribosome of the transporter is activated by the anti-UGG ribosome-reading code , with the amino acid Tryptophan
translation
The large ribosome unit contains an enzyme (aminoacyl tRNA synthetase) that binds the amino acids together by peptide bonds , Any RNA ends up with an end or stop blade.
translation
Then the formation of proteins stops, and the formed peptide chain separates as well as the two units of ribosome separate
translation
To start the translation, the ribosome binds to the mRNA at the AUG start codon
initiation
The rRNA is bound by pairing the anticodon with the codon
Then the ribosome moves from one blade to another along the mRNA, and the amino acids are added one by one
elongation
Translation stops when the three endpoints are present on the mRNA
termination
UAA,UAG, UGA
Terminal codon
