Unit 2 Flashcards
Identify the purpose of protéine fixatrice, l’hélicase and l’ADN gyrase as well as the stage in DNA duplication they’re used in
Initiation
- Hélicase : breaks open the DNA
- Protéine fixatrice : holds the two brins appart
- ADN gyrase : goes ahead of l’hélicase, breaks the bonds ahead of it and puts them back together to reduce tension
Identify the purpose of l’ADN polymérase 3 and l’ARN primase as well as the stage in DNA duplication they’re used in
Élongation
- ARN primase : places ARN that the ADN builds off of. If the ADN that creates a copy is oriented 3’ to 5’, it places only one amorce. If it’s oriented the opposite way, it places multiple amorces
- ADN polymérase III : adds nucléotides starting from the amorces
Identify the purpose of l’ADN polymérase 1 and l’ADN ligase as well as the stage in DNA duplication they’re used in
Terminaison : brin discontinu
ADN polymérase 1 : turns the amorces d’ARN in ADN
ADN ligase : links the space between the separated pieces of ADN
Définitions : Fragments d’Okazaki, amorces, brin continue, brin discontinu
Fragments d’Okazaki : fragments d’ADN sur le brin discontinu.
Amorces : segments d’ADN placés par l’ARN primase
Brin continue :
Brin discontinu :
Explain the difference between duplication on the brin continu vs. discontinu
Continu : l’amorce d’ARN is placed at the beginning of the brin and the nucléotides build off of it until they reach the end of the brin
Discontinu : L’ARN is placed after the beginning of the brin because the new brin has to be built from 5’ to 3’, more pieces of ARN have to be placed on intervals so that the brin can continue to be built in the right direction. Later the ARN is replaced
What’s the difference between ADN and ARN
ADN : 2 brins, pour la réplication et la transmission d’informations génétique
ARN : simple brin, trois types (ARNm, ARNt, ARNr)
What’s ARNm
Transports the genetic information from the noyau to the cytoplasme where the protein can be fabricated
What’s ARNt
Transports acides aminés to ARNm
Name the two parts of transmission of information (DNA –> protein)
Transcription
Traduction
Explain transcription
It’s the method used to transfer genetic information from ADN to ARNm. It’s done in the noyau and is composed of three sub-steps (initiation, élongation, terminaison)
Explain the sub-steps of transcription
- initiation : ARN polymérase links itself to l’ADN on the séquence promoteur (boîte TATA)
- élongation : ARN polymérase makes ARNm from 5’ to 3’. The brin codant is the one that will be transcribed so the brin non codant is what you build the ARNm off of
- terminaison : the ARN polymérase continues until it reaches a séquence de terminaison
Name what is added to ARNm after it’s made and the purpose
Coiffe 5’ and Queue poly-A (added to 3’)
1. Protect ARNm from enzymes cytoplasmique
2. Stabiliser l’ARNm
What is l’épissage, an intron, an exon and a codon
Épissage : when you remove non codant parts from the ARNm
Intron : unnecessary part of the gene
Exon : necessary part of the gene
Codon