11/27/2012Take a lime green slip, a notes

sheet, and a picture sheet from the front table. Glue/tape/staple them into your journals according to the

following instructions:The lime green slip must be first before the notes and the picture.

The notes and the picture should be placed on pages that face each

other.

Protein Synthesis

DNA vs.RNA

• Double-stranded• Deoxyribose• A,G, C, T

• Single stranded• Ribose• A, G, C, U

DNA vs.RNA

NucleusThe office

The Boss never leaves

DNA – The Boss

mRNA – Ms. ReneSecretary

She’s a foreigner

Protein Synthesis

Protein synthesis is the making of proteins, using the information that is found in DNA.

Proteins are long chains of small molecules called amino acids. Different proteins are made by using a different sequence of amino acids.

Pieces of information in DNA are called genes.

Transcription: means write across

Protein synthesis begins with the DNA molecule. The DNA of this gene will unzip like it does in replication. *The enzyme that separates the DNA strand at a specific gene is helicase.

In protein synthesis, only one strand of the DNA will be used.

Transcription: means write across

A single strand of mRNA forms and transcribes (copies) the genetic information from the DNA. This strand of RNA is called messenger RNA or mRNA. *The enzyme that connects and assembles the ribonucleotides is called RNA polymerase

The DNA “zips” closed and remains in the nucleus .

The mRNA will leave the nucleus and travel to a ribosome.

RNA which stands for RIBONUCLEIC ACID is

single stranded, contains a ribose sugar, and

has Uracil instead of Thymine.

Comparing RNA and DNA

Image courtesy of Wikimedia Commons

T

AG

TC

AT

C

A

GG

5’

3’

5’

3’A

TC

AG

TA

G

T

CC

5’

3’

GT CA UAAAAAA TTTTT CCCCC GGGGGG UUUU

3’

5’

DNA Helicase Touch the helicase!

T

AG

TC

AT

C

A

GG

5’

3’

5’

3’A

TC

AG

TA

G

T

CC

5’

3’

GT CA UAAAAAA TTTTT CCCCC GGGGGG UUUU

3’

5’

Assemble your

mRNA strand!!

Hit Me when done!

T

AG

TC

AT

C

A

GG

5’

3’

5’

3’A

TC

AG

TA

G

T

CC

5’

3’

GT CA UAAAAAA TTTTT CCCCC GGGGGG UUUU

3’

5’

RNA polymerase

UC

C

C

A

A

A G

G

U

U

T

AG

TC

AT

C

A

GG

5’

3’

5’

3’A

TC

AG

TA

G

T

CC

5’

3’

A

A

A

U

U

C

C

G

GU

C

3’

5’

Protein Synthesis- Part 1Transcription

From HHMI’s Biointeractive: DNA Animations/Transcription (basic)

http://www.hhmi.org/biointeractive/dna/DNAi_transcription_vo1.html

11/28/2012Take out your notes from

yesterday. On the green slip of paper, fill in the mRNA

row using the original DNA strand. Remember: Ms. Rene

cannot write “T”

Quick Review!

Where does TRNASCRIPTION take

place?

NucleusThe office

The Boss never leaves

Where do we get the information to make

different types of proteins?

DNA – The Boss

Who delivers the message to the

workers?

mRNA – Ms. ReneSecretary

She’s a foreigner

Quick Quiz1. What is the name of the enzyme that

unwinds DNA?2. What is the process where a secret

message goes ACROSS the nuclear membrane?

3. What carries the sequence from the DNA out of the nucleus?

4. How many strands are copied on the original DNA molecule?

5. What happens to the DNA once the messenger detaches?

rRNA – Bobettethe Ribosome

She builds proteins one amino acid at

a time

tRNA – Terrythe Delivery Boy

Terry brings Bobette

whatever she needs

Translation The mRNA contains information in sets of

three and each set of three codes for a specific amino acid. Each set of three is called a CODON.CODON.

The mRNA molecule will attach to the ribosome found in the cell. Ribosomes are also made up of RNA. Ribosomal RNA is called rRNA.

Where in the cell are ribosomes (rRNA) made?

Translation

A molecule of transfer RNA or tRNA will carry in the proper amino acid. If the tRNA ANTICODON matches with the codon sequence, the tRNA will attach temporarily to the mRNA strand.

Translation

After a 2nd tRNA molecule matches an mRNA codon, an amino acid will be deposited. tRNAs will continue to deposit amino acids when codons and anti-codons match. The bond created between 2 amino acids is called a peptide bond.

The chain of amino acids is called a polypeptide or a protein

Ribosome

5’

3’ 3’A A AU U C CG G U C

5’3’

U UC

Arginine

A GG

Serine

A UC

Valine

AAG

Leucine

Ribosome

5’

3’ 3’A A AU U C CG G U C

5’3’

U UC

Arginine

A GG

Serine

A UC

Valine

AAG

Leucine

Ribosome

5’

3’ 3’A A AU U C CG G U C

5’3’U UC

Arginine

A GG

Serine

A UC

Valine

AAG

Leucine

Ribosome

5’

3’ 3’A A AU U C CG G U C

5’3’U UC

ArginineA GG

Serine

Peptide bond

A UC

Valine

AAG

Leucine

Ribosome

5’

3’ 3’A A AU U C CG G U C

5’3’

Arginine

Peptide bond

A UC

Valine

A GGSerine

AAG

Leucine

Ribosome

5’

3’ 3’A A AU U C CG G U C

5’3’

Arginine

A UC

ValineSerine

Peptide bond

AAG

Leucine

Ribosome

5’

3’ 3’A A AU U C CG G U C

5’3’

Arginine ValineSerine

A S V L G S AA V

R

AAG

Leucine

U

Quick Quiz1. What is the process where the mRNA

drops off the message to the ribosome?2. What are the 3 types of RNA?3. A sequence of 3 nucleotides on the

mRNA strand that codes for a specific amino acid is called a what?

4. What is the name of the bond that is formed between two amino acids?

5. How do amino acids get into the body in the first place?

DNA unwinds and unzips. Free RNA nucleotides attach to exposed bases. Bases combine to form mRNA strand. DNA reassembles. mRNA leaves the nucleus. The mRNA arrives at the ribosome. When the codon of the mRNA complements the anti-codon

of the tRNA molecule, the tRNA places the amino acid attached in the position.

tRNAs continue to deposit amino acids when codons and anticodons match.

One by one amino acids are added to the growing chain until the ribosome has reached the STOP codon.

Once the protein has been synthesized completely, it is removed from the ribosome for further processing and to perform its function.

Proteins like insulin and lactase exit to the Golgi bodies to be packaged and shipped out of the cell.

Protein Synthesis- Part 2Translation

From HHMI’s Biointeractive: DNA Animations/Translation (basic)

http://www.hhmi.org/biointeractive/dna/DNAi_translation_vo1.html

11/29/2012Please take the 2

worksheets from the front table, take out your

transcription & translation worksheet from yesterday, and your protein synthesis

notes.

Draw the flow chart in your journal, then fill it in using the following words: Amino acids, mRNA, mRNA codon, nucleus, nuclear pore, peptide bonds, ribosome, transcription, translation

DNADNA

mRNAmRNA

TranscriptionTranscription

TranslationTranslationRibosomeRibosome

AUAAUA UUGUUG AAGAAG AGCAGC CACCAC GCUGCU AAAAAA GAGGAG UGAUGA

AUAAUA UUGUUG AAGAAG AGCAGC CACCAC GCUGCU AAAAAA GAGGAG UGAUGA

UAUUAU AACAAC UUCUUC UCGUCG GUGGUG CGACGA UUUUUU CUCCUC ACUACU

A-TC-G

T-AA-UC-G

Insert practice here

Last Thought 11/28/11 Write the sequence for a segment of RNA

that codes for the following chain of amino acids:

valine – serine – proline – glycine – leucine

Explain why your sequence is likely to be different than your partner’s.