Unit 3 Flashcards
mRNA
translated by ribosome into protein
tRNA
delivers amino acids to protein
rRNA
binds to amino acid in polypeptide to form ribosome
Hershey chase
32P and 35S infected bacterial cells with these isotopes
Chargaff
%A=%T
Helicase
binds to the origin to break hydrogen bonds
Single stranded binding protein
attached to loose DNA strand so they don’t attract each other
Topoisomerase
Relives tension by cutting DNA strands near replication than rejoining them
RNA primer
tells replication molecule where to start
Polymerase add new nucleotides to which end?
3’
Okazaki fragments
new strand of DNA on lagging
semiconservative
separates 2 parental strands and builds new complementary strand for each
Telomeres
Repeating sequence of DNA found in ends of chromosome
Replication origin
y shape formed when separating and unwinding strands
Transcription-Initiation
RNA binds to DNA at TATA box
Transcription-Elongation
RNA molecules based paired with template strand
Transcription-Termination
RNA copy released
Poly(A)tailing
Chain of A nucleotides added to 3’ end
Capping
7 G added to 5’ end
Splicing
Removing introns
Alternative splicing
exons put in different combinations
Why 3 letter codons
needs to code for 20 amino acids
Prokaryotes Transcription
No introns, no post transcription modifications, and occur throughout cell
Eukaryotes Transcription
both introns and exons, must go through modifications
Post Translation
Peptide must be folded in the right way so met is cut out
Point mutation
Change in a single nucleotide within a gene
Frame shift mutation
adding a codon or deleting a codon causing codon to be read in a diffrent way
Translocation
movement of an entire DNA sequence to another chromosome
Histones
extremely coiled DNA around proteins
Recombinant DNA
DNA strand created by mixing multiple pieces of DNA from different sources
EcoRI
Cuts phosphodiester bond in DNA backbone causing nucleotides to become weak
Gel electrophoresis
separates molecules based on size and charge
