Transcript Protein synthesis

Review
• Compare and Contrast
RNA vs. DNA.
• What is the significant
difference between
Prokaryotes and
Eukaryotes?
• What are the three
types of RNA?
DNA
• Sugar?
• Nitrogen bases?
• Double stranded?
RNA
ribonucleic acid
• Single stranded
• Contain “ribose sugar”
• Small enough to leave
the nucleus
• 3 types of RNA
– mRNA, tRNA and rRNA
• Nitrogen bases:
– A, G, C, Uracil
Protein Synthesis
• Process where DNA
encodes for the
production of amino
acids
• What does the body
do with the proteins
after they are made ?
Protein diagrams
Two major Steps
• Transcription
– Information is coded from DNA to make mRNA
• Translation
– Information coded from mRNA is used to make
proteins
Transcription Helpers
• Helicase: “unzipper”
• RNA poly: adds RNA nucleotides
Transcription
• mRNA is made from
DNA
• Initiation,
Elongation,
Termination
• http://www.stolaf.edu/
people/giannini/biolog
ical%20anamations.ht
ml
Steps of Transription
1.
2.
3.
4.
5.
Helicase unwinds the DNA
RNA poly binds to the promotor site
RNA poly adds RNA nucleotides
RNA reaches stop codon
mRNA detaches and moves to
cytoplasm (or stays in cytoplasm of
prok)
Translation
• Process by which
proteins are
“translated” coded
from mRNA
• Takes place in
Cytoplasm
• ID the three types
of RNA in the
diagram.
Translation
• mRNA contains a
message that must be
translated
• mRNA contains codons
(3 nucleotide
sequence.)
• Each codon corresponds
to an amino acid
Translation
• tRNA contains an
anti-codon and an
amino acid
• One specific AA can
correspond to more
than one codon
(degenerate)
Steps of Translation
1. rRNA subunit attaches to the mRNA strand at
the start codon: AUG
2. tRNA carries an anti-codon and a protein that
corresponds to the genetic code
3. Peptide bonds form between the amino acids.
Once the tRNA reaches a stop codon, a
release factor binds and releases the protein
into the cytoplasm where it is used as directed
by the cell.
Initiation, elongation, termination
How it works
• http://www.stolaf.edu/people/giannini/biolo
gical%20anamations.html
• http://highered.mcgrawhill.com/sites/0072437316/student_view0/
chapter15/animations.html#
mRNA: AUG CCG AUC AUG UAA
Protein Synthesis animations
• http://www.stolaf.edu/people/giannini/biolo
gical%20anamations.html
• http://highered.mcgrawhill.com/sites/0072437316/student_view0/
chapter15/animations.html#