Xam 3 Flashcards
What is the general structure of DNA monomer
Phosphate
Deoxyribose (sugar)
Nitrogenous Base (adeine)
What are the two base pairings possible between two nucleotides?
A-T
C-G
The DNA backbone
Sugar and phosphate groups
Antiparallel
The two strands run in opposite directions 5’ carbon end faces 3’ carbon end
Complementary
Based on each strand pair specifically with one another A-T and C-G
What happens in RNA
In RNA Uracil replaces thymine
Helicase
The enzyme that unwinds and unzips the DNA molecule
Single strand binding proteins
Attach to the loose strands of DNA to keep them from re forming the hydrogen bonds helicase broke apart
Primase
Lays a shirt section of RNA primer to show polymerase where to begin
DNA polymerase
Binds to DNA molecule and connects nucleotides in the correct order
Leading Strand
DNA polymerase follows helicase as it unzips the DNA
3’
Leading strand
5’
Lagging strand
Lagging strand
Follows in the opposite direction of helicase and polymerase, lagging strands small chunks of replicated DNA is called the Okazaki fragments
Ligase
Re zips the DNAs sugar phosphate backbone and connects gaps left in the lagging strand
Topoisomerase
Relives stress on the double helix that results from unwinding
Origin of Replication
Each point at which DNA synthesis is initiated
Telomere
The end of a eukaryotic chromosome is capped by the repeating sequence telomere (3’-GGGATT-5’)
Stages of transcription
Initiation
Elongation
Termination
Template strand
3’ to 5’ (original strand)
Coding Strand
5’ to 3’ the strand being translated from the original given its base pair
How does elongation work
RNA grows 5’ to 3’ but template DNA is read 3’ to 5’
DNA to MRNA
Transcription
MRNA to PROTEIN
Translation
Start and Stop Codon
AUG and MET
What do tRNAs do
Matches the codon with the proper amino acid
Where does the amino acid attach
3’
Where does transcription occur in prokaryotes and eukaryotes
In prokaryotes it occurs in the cytoplasm in eukaryotes it occurs in the nucleus
How does a codon in MRNA base pair with the anticodon of TRNA
Each anticodon matches up with a codon on the MRNA
