[GenBio 2] Central Dogma - Lesson 1

where in the DNA can genetic instructions be found?

nitrogenous bases

sequence of processes in central dogma

replication —> transcription —> translation

enzymes involved in replication

helicase, gyrase, SSBPs, primase, DNA polymerase III, DNA polymerase I, DNA ligase

what does the helicase do?

breaks H-bonds and exposes nitrogenous bases

what does the gyrase do?

prevents supercoiling of exposed nitrogenous bases

what does the primase do?

add binding sites —> short RNA primer (8-12 nucleotides)

what does the DNA polymerase III do?

adds complementary bases to parent strand

how does DNA polymerase III read?

from 3’ to 5’

what does the DNA polymerase I do?

removes RNA primers and replaces with DNA nucleotides

what does the DNA ligase do?

seals gaps between DNA segment

what are the fragments called in the lagging strand?

okazaki fragment

the resulting strand (from replication) must always run from

5’ to 3’

what is Chargaff’s rule?

A = T; G = C

replication is a semiconservative process because?

1 parent DNA will always produce 2 daughter DNA strands with one strand each from the parent DNA

enzyme involved in transcription

RNA polymerase

what does the RNA polymerase do?

produces complementary mRNA

what are the two types of promoter sequences (where RNA polymerase will attach)

Pribnow Box, Goldberg-Hogness Box

explain the Pribnow Box

for prokaryotic cells (ex. bacteria), 3’ TATAAT 5’

explain the Goldberg-Hogness Box

for eukaryotic cells, 3’ TATTAA 5’

how many strands can undergo transcription?

1

relationships of strands

template to coding & mRNA —> complementary; coding to mRNA —> same, just change T to U

explain retroviruses

complementary DNA is synthesized through REVERSE TRANSCRIPTION w/ RNA template