Protein Synthesis - Chandler Unified School District · 2013-07-16 · Protein Synthesis: From Gene...
Transcript of Protein Synthesis - Chandler Unified School District · 2013-07-16 · Protein Synthesis: From Gene...
![Page 1: Protein Synthesis - Chandler Unified School District · 2013-07-16 · Protein Synthesis: From Gene to Protein • Genes are stretches of nucleotides organized in triplets • Different](https://reader034.fdocuments.us/reader034/viewer/2022050504/5f965b46af2da038022f598c/html5/thumbnails/1.jpg)
Protein Synthesis
![Page 2: Protein Synthesis - Chandler Unified School District · 2013-07-16 · Protein Synthesis: From Gene to Protein • Genes are stretches of nucleotides organized in triplets • Different](https://reader034.fdocuments.us/reader034/viewer/2022050504/5f965b46af2da038022f598c/html5/thumbnails/2.jpg)
Protein SynthesisHow Genes Become Constituent Molecules
![Page 3: Protein Synthesis - Chandler Unified School District · 2013-07-16 · Protein Synthesis: From Gene to Protein • Genes are stretches of nucleotides organized in triplets • Different](https://reader034.fdocuments.us/reader034/viewer/2022050504/5f965b46af2da038022f598c/html5/thumbnails/3.jpg)
Mendel and The Idea of Gene
![Page 4: Protein Synthesis - Chandler Unified School District · 2013-07-16 · Protein Synthesis: From Gene to Protein • Genes are stretches of nucleotides organized in triplets • Different](https://reader034.fdocuments.us/reader034/viewer/2022050504/5f965b46af2da038022f598c/html5/thumbnails/4.jpg)
What is a Chromosome?
![Page 5: Protein Synthesis - Chandler Unified School District · 2013-07-16 · Protein Synthesis: From Gene to Protein • Genes are stretches of nucleotides organized in triplets • Different](https://reader034.fdocuments.us/reader034/viewer/2022050504/5f965b46af2da038022f598c/html5/thumbnails/5.jpg)
A chromosome is a molecule of DNA
True
False
50%50%
1. True2. False
![Page 6: Protein Synthesis - Chandler Unified School District · 2013-07-16 · Protein Synthesis: From Gene to Protein • Genes are stretches of nucleotides organized in triplets • Different](https://reader034.fdocuments.us/reader034/viewer/2022050504/5f965b46af2da038022f598c/html5/thumbnails/6.jpg)
Protein SynthesisHow Genes Become Constituent Molecules
![Page 7: Protein Synthesis - Chandler Unified School District · 2013-07-16 · Protein Synthesis: From Gene to Protein • Genes are stretches of nucleotides organized in triplets • Different](https://reader034.fdocuments.us/reader034/viewer/2022050504/5f965b46af2da038022f598c/html5/thumbnails/7.jpg)
Protein Synthesis: What Is It?
• All proteins are synthesized according to instructions contained in the DNA nucleotide sequence, which is unique to every individual
• Protein synthesis is a two step process that consists of transcription and translation.
![Page 8: Protein Synthesis - Chandler Unified School District · 2013-07-16 · Protein Synthesis: From Gene to Protein • Genes are stretches of nucleotides organized in triplets • Different](https://reader034.fdocuments.us/reader034/viewer/2022050504/5f965b46af2da038022f598c/html5/thumbnails/8.jpg)
Protein Synthesis: What Is It?
• During transcription a molecule of messenger RNA (mRNA) is synthesized according to instructions provided by the DNA
• During translation, a polypeptide chain will be produced according to instructions provided by the mRNA
![Page 9: Protein Synthesis - Chandler Unified School District · 2013-07-16 · Protein Synthesis: From Gene to Protein • Genes are stretches of nucleotides organized in triplets • Different](https://reader034.fdocuments.us/reader034/viewer/2022050504/5f965b46af2da038022f598c/html5/thumbnails/9.jpg)
Protein Synthesis in Prokaryotes
• In prokaryotes, transcription and translation occur in the same cellular compartment — the cytosol. Ribosomesare the site of translation
![Page 10: Protein Synthesis - Chandler Unified School District · 2013-07-16 · Protein Synthesis: From Gene to Protein • Genes are stretches of nucleotides organized in triplets • Different](https://reader034.fdocuments.us/reader034/viewer/2022050504/5f965b46af2da038022f598c/html5/thumbnails/10.jpg)
Protein Synthesis in Eukaryotes• In eukaryotes, mRNA is
synthesized in the nucleus from pre-messenger RNA (pre-mRNA) molecules, and then shipped to the cytoplasm, where translation occurs
• RNA processing (or post-transcriptional modification) refers to the molecular mechanisms that lead to the production of mRNA from pre-mRNA.
![Page 11: Protein Synthesis - Chandler Unified School District · 2013-07-16 · Protein Synthesis: From Gene to Protein • Genes are stretches of nucleotides organized in triplets • Different](https://reader034.fdocuments.us/reader034/viewer/2022050504/5f965b46af2da038022f598c/html5/thumbnails/11.jpg)
The main difference between protein synthesis in eukaryotes and
in prokaryotes is:
whe
re the
proc
ess h
...
wha
t the p
roces
s pr...
the p
articip
ants
in th.
..
33% 33%33%
1. where the process happens2. what the process produces3. the participants in the process
![Page 12: Protein Synthesis - Chandler Unified School District · 2013-07-16 · Protein Synthesis: From Gene to Protein • Genes are stretches of nucleotides organized in triplets • Different](https://reader034.fdocuments.us/reader034/viewer/2022050504/5f965b46af2da038022f598c/html5/thumbnails/12.jpg)
This cartoon represents:
prote
in sy
nthes
is in..
.
trans
lation
in pr
okar.
..
prote
in sy
nthes
is in.
..
33% 33%33%
1. protein synthesis in eukaryotes
2. translation in prokaryotes3. protein synthesis in
prokaryotes
![Page 13: Protein Synthesis - Chandler Unified School District · 2013-07-16 · Protein Synthesis: From Gene to Protein • Genes are stretches of nucleotides organized in triplets • Different](https://reader034.fdocuments.us/reader034/viewer/2022050504/5f965b46af2da038022f598c/html5/thumbnails/13.jpg)
Protein Synthesis: From Gene to Protein
• Genes are stretches of nucleotides organized in triplets
• Different arrangements or DNA triplets encode for each one of the 20 amino acids that make proteins
• During transcription, a DNA triplet will produce an mRNA codon.
• During translation, a codon will constitute an amino acid
![Page 14: Protein Synthesis - Chandler Unified School District · 2013-07-16 · Protein Synthesis: From Gene to Protein • Genes are stretches of nucleotides organized in triplets • Different](https://reader034.fdocuments.us/reader034/viewer/2022050504/5f965b46af2da038022f598c/html5/thumbnails/14.jpg)
Protein Synthesis: From Gene to Protein
DNA
mRNA
Protein
Transcription
Translation
![Page 15: Protein Synthesis - Chandler Unified School District · 2013-07-16 · Protein Synthesis: From Gene to Protein • Genes are stretches of nucleotides organized in triplets • Different](https://reader034.fdocuments.us/reader034/viewer/2022050504/5f965b46af2da038022f598c/html5/thumbnails/15.jpg)
Transcription: What Is It Transcribed?
• RNA polymerase binds to the gene’s promoter region and starts making a molecule of mRNA until it finds a “mark” in the gene or termination sequence.
• The term transcription unit refers to the segment of DNA between the sites of initiation and termination of transcription by RNA polymerase. More than one gene may reside in a transcription unit.
![Page 16: Protein Synthesis - Chandler Unified School District · 2013-07-16 · Protein Synthesis: From Gene to Protein • Genes are stretches of nucleotides organized in triplets • Different](https://reader034.fdocuments.us/reader034/viewer/2022050504/5f965b46af2da038022f598c/html5/thumbnails/16.jpg)
Transcription: Initiation
Nascent mRNA: RNA transcript
![Page 17: Protein Synthesis - Chandler Unified School District · 2013-07-16 · Protein Synthesis: From Gene to Protein • Genes are stretches of nucleotides organized in triplets • Different](https://reader034.fdocuments.us/reader034/viewer/2022050504/5f965b46af2da038022f598c/html5/thumbnails/17.jpg)
Transcription: Elongation
![Page 18: Protein Synthesis - Chandler Unified School District · 2013-07-16 · Protein Synthesis: From Gene to Protein • Genes are stretches of nucleotides organized in triplets • Different](https://reader034.fdocuments.us/reader034/viewer/2022050504/5f965b46af2da038022f598c/html5/thumbnails/18.jpg)
Transcription: Elongation
• RNA is synthesized according to DNA/RNA base pairing rules:
A (DNA) — U (RNA)
G (DNA) — C (RNA)T (DNA) — A (RNA)C (DNA) — G (RNA
![Page 19: Protein Synthesis - Chandler Unified School District · 2013-07-16 · Protein Synthesis: From Gene to Protein • Genes are stretches of nucleotides organized in triplets • Different](https://reader034.fdocuments.us/reader034/viewer/2022050504/5f965b46af2da038022f598c/html5/thumbnails/19.jpg)
The Making of an mRNA
DNA 5’ ATTGCGTAGTGGGATTAT 3’
RNA
![Page 20: Protein Synthesis - Chandler Unified School District · 2013-07-16 · Protein Synthesis: From Gene to Protein • Genes are stretches of nucleotides organized in triplets • Different](https://reader034.fdocuments.us/reader034/viewer/2022050504/5f965b46af2da038022f598c/html5/thumbnails/20.jpg)
Transcription: Termination
![Page 21: Protein Synthesis - Chandler Unified School District · 2013-07-16 · Protein Synthesis: From Gene to Protein • Genes are stretches of nucleotides organized in triplets • Different](https://reader034.fdocuments.us/reader034/viewer/2022050504/5f965b46af2da038022f598c/html5/thumbnails/21.jpg)
RNA polymerase : RNA transcript : unwound DNA
trans
lation
’s ini
tiatio
n
trans
lation
’s elo
ngati
on
trans
lation
’s term
inatio
n
33% 33%33%
1. translation’s initiation2. translation’s elongation3. translation’s termination
![Page 22: Protein Synthesis - Chandler Unified School District · 2013-07-16 · Protein Synthesis: From Gene to Protein • Genes are stretches of nucleotides organized in triplets • Different](https://reader034.fdocuments.us/reader034/viewer/2022050504/5f965b46af2da038022f598c/html5/thumbnails/22.jpg)
RNA polymerase : promoter : transcription unit
trans
lation
’s ini
tiatio
n
trans
lation
’s elo
ngati
on
trans
lation
’s term
inatio
n
33% 33%33%
1. translation’s initiation2. translation’s elongation3. translation’s termination
![Page 23: Protein Synthesis - Chandler Unified School District · 2013-07-16 · Protein Synthesis: From Gene to Protein • Genes are stretches of nucleotides organized in triplets • Different](https://reader034.fdocuments.us/reader034/viewer/2022050504/5f965b46af2da038022f598c/html5/thumbnails/23.jpg)
This cartoon illustrates:
trans
lation
’s ini
tiatio
n
trans
lation
’s elo
ngati
on
trans
lation
’s term
inatio
n
33% 33%33%
1. translation’s initiation2. translation’s elongation3. translation’s termination
![Page 24: Protein Synthesis - Chandler Unified School District · 2013-07-16 · Protein Synthesis: From Gene to Protein • Genes are stretches of nucleotides organized in triplets • Different](https://reader034.fdocuments.us/reader034/viewer/2022050504/5f965b46af2da038022f598c/html5/thumbnails/24.jpg)
Transcription: Eukaryotic Promoters
• In eukaryotes, promoters are activated by DNA binding proteins or transcription factors
• TATA boxes are segments of about 30 base pairs to which RNA polymerase binds
![Page 25: Protein Synthesis - Chandler Unified School District · 2013-07-16 · Protein Synthesis: From Gene to Protein • Genes are stretches of nucleotides organized in triplets • Different](https://reader034.fdocuments.us/reader034/viewer/2022050504/5f965b46af2da038022f598c/html5/thumbnails/25.jpg)
Transcription in Eukaryotes: Splicing of pre-mRNA Molecules
• Eukaryotic transcripts (pre-mRNA) contains exons(coding sequences) and introns (non coding sequences)
• Post-transcriptional modifications (i.e. splicing) remove introns before shipping the final mRNA to the cytoplasm
![Page 26: Protein Synthesis - Chandler Unified School District · 2013-07-16 · Protein Synthesis: From Gene to Protein • Genes are stretches of nucleotides organized in triplets • Different](https://reader034.fdocuments.us/reader034/viewer/2022050504/5f965b46af2da038022f598c/html5/thumbnails/26.jpg)
Transcription in Eukaryotes: Splicing of pre-mRNA Molecules
• Spliceosomes are organelles in which the excision and splicing reactions that remove introns from pre-mRNA occur
• Ribozymes and small nuclear RNAs(snRNA) are contained in spliceosomes
![Page 27: Protein Synthesis - Chandler Unified School District · 2013-07-16 · Protein Synthesis: From Gene to Protein • Genes are stretches of nucleotides organized in triplets • Different](https://reader034.fdocuments.us/reader034/viewer/2022050504/5f965b46af2da038022f598c/html5/thumbnails/27.jpg)
Transcription in Eukaryotes: Splicing of pre-mRNA Molecules
![Page 28: Protein Synthesis - Chandler Unified School District · 2013-07-16 · Protein Synthesis: From Gene to Protein • Genes are stretches of nucleotides organized in triplets • Different](https://reader034.fdocuments.us/reader034/viewer/2022050504/5f965b46af2da038022f598c/html5/thumbnails/28.jpg)
Introns are not translated.
True
False
50%50%
1. True2. False
![Page 29: Protein Synthesis - Chandler Unified School District · 2013-07-16 · Protein Synthesis: From Gene to Protein • Genes are stretches of nucleotides organized in triplets • Different](https://reader034.fdocuments.us/reader034/viewer/2022050504/5f965b46af2da038022f598c/html5/thumbnails/29.jpg)
Splicing only occurs in eukaryotes.
True
False
50%50%
1. True2. False
![Page 30: Protein Synthesis - Chandler Unified School District · 2013-07-16 · Protein Synthesis: From Gene to Protein • Genes are stretches of nucleotides organized in triplets • Different](https://reader034.fdocuments.us/reader034/viewer/2022050504/5f965b46af2da038022f598c/html5/thumbnails/30.jpg)
Translation: Production of Polypeptide Chains
![Page 31: Protein Synthesis - Chandler Unified School District · 2013-07-16 · Protein Synthesis: From Gene to Protein • Genes are stretches of nucleotides organized in triplets • Different](https://reader034.fdocuments.us/reader034/viewer/2022050504/5f965b46af2da038022f598c/html5/thumbnails/31.jpg)
Translation: transfer RNA (tRNA)
• Every transfer RNA (tRNA) has a specific sequence of nucleotides, complementary to an mRNA codon — the anticodon.
• Opposite to the anticodon, there is an attachment site specific for each of the 20 amino acids.
![Page 32: Protein Synthesis - Chandler Unified School District · 2013-07-16 · Protein Synthesis: From Gene to Protein • Genes are stretches of nucleotides organized in triplets • Different](https://reader034.fdocuments.us/reader034/viewer/2022050504/5f965b46af2da038022f598c/html5/thumbnails/32.jpg)
Translation: transfer RNA (tRNA)
![Page 33: Protein Synthesis - Chandler Unified School District · 2013-07-16 · Protein Synthesis: From Gene to Protein • Genes are stretches of nucleotides organized in triplets • Different](https://reader034.fdocuments.us/reader034/viewer/2022050504/5f965b46af2da038022f598c/html5/thumbnails/33.jpg)
Translation: mRNA/tRNAInteraction
• The recognition of codon(mRNA) and anticodon(tRNA) occurs in the ribosomes.
• Ribosomes have sites of tRNA anchorage and exiting
• A growing polypeptide will be produced following instructions in the mRNA
![Page 34: Protein Synthesis - Chandler Unified School District · 2013-07-16 · Protein Synthesis: From Gene to Protein • Genes are stretches of nucleotides organized in triplets • Different](https://reader034.fdocuments.us/reader034/viewer/2022050504/5f965b46af2da038022f598c/html5/thumbnails/34.jpg)
Translation: Initiation and Elongation of the Polypeptide Chain
• A start codon (AUG) complements with the Methionine(Met) tRNA in the ribosome, constituting the translation initiation complex
• A new anticodon will land in the A site, and its amino acid will join Met. The tRNA will slide to the P site leaving the A site free for another anticodon
![Page 35: Protein Synthesis - Chandler Unified School District · 2013-07-16 · Protein Synthesis: From Gene to Protein • Genes are stretches of nucleotides organized in triplets • Different](https://reader034.fdocuments.us/reader034/viewer/2022050504/5f965b46af2da038022f598c/html5/thumbnails/35.jpg)
Translation: Initiation and Elongation of the Polypeptide Chain
![Page 36: Protein Synthesis - Chandler Unified School District · 2013-07-16 · Protein Synthesis: From Gene to Protein • Genes are stretches of nucleotides organized in triplets • Different](https://reader034.fdocuments.us/reader034/viewer/2022050504/5f965b46af2da038022f598c/html5/thumbnails/36.jpg)
Translation: Termination
• A stop codon (UAG, UAA, or UGA) signals the end of the mRNA molecule. A release factor triggers the disassembling of the two ribosomal units and the mRNA molecule.
![Page 37: Protein Synthesis - Chandler Unified School District · 2013-07-16 · Protein Synthesis: From Gene to Protein • Genes are stretches of nucleotides organized in triplets • Different](https://reader034.fdocuments.us/reader034/viewer/2022050504/5f965b46af2da038022f598c/html5/thumbnails/37.jpg)
uracil : codon : transcription
mRN
A
pre- m
RNA tR
NA DNA
25% 25%25%25%1. mRNA2. pre- mRNA3. tRNA4. DNA
![Page 38: Protein Synthesis - Chandler Unified School District · 2013-07-16 · Protein Synthesis: From Gene to Protein • Genes are stretches of nucleotides organized in triplets • Different](https://reader034.fdocuments.us/reader034/viewer/2022050504/5f965b46af2da038022f598c/html5/thumbnails/38.jpg)
uracil : anticodon : translation
mRN
A
pre- m
RNA tR
NA DNA
25% 25%25%25%1. mRNA2. pre- mRNA3. tRNA4. DNA
![Page 39: Protein Synthesis - Chandler Unified School District · 2013-07-16 · Protein Synthesis: From Gene to Protein • Genes are stretches of nucleotides organized in triplets • Different](https://reader034.fdocuments.us/reader034/viewer/2022050504/5f965b46af2da038022f598c/html5/thumbnails/39.jpg)
thymine : triplet : genetic message
mRN
A
pre- m
RNA tR
NA DNA
25% 25%25%25%1. mRNA2. pre- mRNA3. tRNA4. DNA
![Page 40: Protein Synthesis - Chandler Unified School District · 2013-07-16 · Protein Synthesis: From Gene to Protein • Genes are stretches of nucleotides organized in triplets • Different](https://reader034.fdocuments.us/reader034/viewer/2022050504/5f965b46af2da038022f598c/html5/thumbnails/40.jpg)
Polyribosomes
• An mRNA molecule is generally translated simultaneously by several ribosomesthat constitute polyribosomes
![Page 41: Protein Synthesis - Chandler Unified School District · 2013-07-16 · Protein Synthesis: From Gene to Protein • Genes are stretches of nucleotides organized in triplets • Different](https://reader034.fdocuments.us/reader034/viewer/2022050504/5f965b46af2da038022f598c/html5/thumbnails/41.jpg)
Anchorage of Proteins After Translation
![Page 42: Protein Synthesis - Chandler Unified School District · 2013-07-16 · Protein Synthesis: From Gene to Protein • Genes are stretches of nucleotides organized in triplets • Different](https://reader034.fdocuments.us/reader034/viewer/2022050504/5f965b46af2da038022f598c/html5/thumbnails/42.jpg)
Gene Expression