TRANSCRIPTION

BELLWORK- 3 MINUTES! (WORK QUICKLY)

1. Draw a picture of each of the 3 kinds of RNA

2. Describe the function of each type of RNA

3. Give at least 2 reasons why making proteins is such an important process

4. When you are finished, write down as many things as you can remember about the similarities & differences between DNA & RNA

SO HOW DOES RNA MAKE PROTEINS???

DNA

RNA

Protein

DNA stores information to run cell

Proteins actually DO the work in the cell

RNA’s function

is to make

proteins!

PROTEIN SYNTHESIS

Protein synthesis is the process of making proteins.

It happens in 2 parts:TranscriptionTranslation

FILL IN THE TABLE FOR TRANSCRIPTION

Transcription is the process of making an mRNA copy of the DNA instructions (recipe for a protein). Occurs in the nucleus.

Name of Part: Definition: Where it happens:

Transcription

TRANSCRIPTION VIDEO CLIP

http://www.dnalc.org/resources/3d/TranscriptionBasic_withFX.html (1:52)

STEP1: SIGNAL

The cell receives a signal to make a specific protein.

EXAMPLE

After drinking milk, your cells receive a signal to begin making more LACTASE- the enzyme that breaks down lactose (milk sugar)

What other example can you think of that would

signal cells to make a protein?

RNA polymerase binds to the promoter sequence on DNA (usually “TATA”).

STEP 2 : PROMOTER

PRACTICE

#1- Find & circle the promoter (TATA) in each gene GACCTATAGTCTAG CTATAATGCTACACTGAGCTGCG

CAGGATATCAGATC GATATTACGATGTGACTCGACGC

 

GTCGAACGTATACGGGTGCATGATCCT GTATCGATCGAAATATCGATCGTTA

CAGCTTGCATATGCCCACGTACTAGGA CATAGCTAGCTTTATAGCTAGCAAT

What kind of molecule is RNA polymerase (hint- look at the ending of the word)?

RNA polymerase reads the DNA & makes an mRNA complement of the gene

STEP 3: MRNA MESSAGE

PRACTICE #1- Find & circle the promoter (TATA) in each gene GACCTATAGTCTAG CTATAATGCTACACTGAGCTGCG

CAGGATATCAGATC GATATTACGATGTGACTCGACGC

 

GTCGAACGTATACGGGTGCATGATCCT GTATCGATCGAAATATCGATCGTTA

CAGCTTGCATATGCCCACGTACTAGGA CATAGCTAGCTTTATAGCTAGCAAT

#2- Underline the sequence that will be read by RNA Polymerase

Try #3 on your transcription worksheetG C C T G A C A C G T C A T C C C G A G T A A A

_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _C G G A C U

PRACTICE- PUT STEPS 1-3 TOGETHER

#4 Circle the promoter, underline the sequence to be made into mRNA, make the complementary mRNA underneath

T G C A T A T G G G A T G T G C T G A T C G A T T G A G T G A A C G T A T A C C C T A C A C G A C T A G C T A A C T C A C T

mRNA: G G G A U G U G C T G A U C G A U U G A G U G A

#5 Draw vertical lines on the mRNA strand above to show separate codons

Segments called introns are removed (not part of the recipe)

Segments called exons are kept (final recipe)

STEP 4 : MRNA SPLICING (CUTTING)

TAKE YOUR HANDOUT

Fold it correctly to reveal the hidden picture!

TALK TO YOUR NEIGHBOR

How did the Harry Potter fold-in model the process of mRNA splicing? Explain introns vs exons.

PRACTICECircle the promoter, underline the sequence to be made into

mRNA, make the complementary mRNA underneath

T G C A T A T G G G A T G T G C T G A T C G A T T G A G T G A A C G T A T A C C C T A C A C G A C T A G C T A A C T C A C T

mRNA: G G G A U G U G C T G A U C G A U U G A G U G A

Boxed-in parts = introns

Remove introns: G G G A U G U G C T G A A U U U G A

Mature mRNA: G G G A U G U G C T G A A U U U G A

The mature mRNA moves out of the nucleus

STEP 5 : MRNA LEAVES NUCLEUS

TRANSCRIPTION VIDEO CLIP- ONE MORE TIME

http://www.dnalc.org/resources/3d/TranscriptionBasic_withFX.html

TRANSCRIPTION SUMMARY- SUMMARIZE TRANSCRIPTION TO YOUR NEIGHBOR

TRANSCRIPTION ACTIVITY

1. You and your partner will receive a “signal” in the cytoplasm (lab table) to begin transcription of a specific protein

2. Go into the nucleus (desk-side) & find the appropriate gene on the DNA molecule to transcribe mRNA from

3. Record the mRNA on your worksheet

4. Splice the mRNA according to instructions

5. Take your mature mRNA out of the nucleus & into the cytoplasm to (double check it with the answer key at your lab table)

6. Move to the next lab table to get a new signal & repeat

**Must finish transcribing at least 2 genes. Then you may begin the HW (on back of class practice sheet)

CLOSURE- ON NOTETAKER

Write a note to a student who was absent explaining what they need to know about transcription.

**If you finish early, begin the HW problems

BELLWORK- 1. What part of the word “transcription”

will help you remember that it is about making a message/mRNA?

2. Give a snapshot of transcription by summarizing it in 20-25 words.

TRANSCRIPTION ACTIVITY (20-30 MINS)

1. You and your partner will receive a “signal” in the cytoplasm (lab table) to begin transcription of a specific protein

2. Go into the nucleus (desk-side) & find the appropriate gene on the DNA molecule to transcribe mRNA from

3. Record the mRNA on your worksheet

4. Splice the mRNA according to instructions

5. Take your mature mRNA out of the nucleus & into the cytoplasm to (double check it with the answer key at your lab table)

6. Move to the next lab table to get a new signal & repeat

**Bio 1-2: Must transcribe at least 5 genes total. Ex. credit for each additional gene.

**PreAP: Must transcribe all 8 genes

PREAP – WHAT TO DO UNTIL QUIZ

1. Check HW with answer key (no late HW accepted)

2. Organize notebook & unit divider3. Use RNA review sheet to prepare

IF YOU FINISH EARLY….

Bio 1-2: 1. Start the back of the pink practice sheet (the

HW side) – good practice for transcription quiz @ end of class today!

2. Review your transcription notes- quiz @ end of class

PreAP: 1. Quiz your partner on the RNA Notetaker &

Protein Synthesis Notetaker to review for transcription quiz

TRANSCRIPTION VIDEO CLIP- ONE MORE TIMEWITH THE SOUND OFF- NARRATE TO YOUR NEIGHBOR

http://www.dnalc.org/resources/3d/TranscriptionBasic_withFX.html

CLOSURE- ON NOTETAKER

Write a note to a student who was absent explaining what they need to know about transcription.

**If you finish early, begin the HW problems (Bio 1-2)

TRANSLATION

BELLWORK1. Look at your transcription simulation (blue) from

yesterday…what 3 letter codon tends to appear near the beginning of every mature mRNA?

2. Give a possible function of this codon based on its appearance near the beginning of mRNA strands.

3. Summarize each of the 5 steps of transcription

4. Make an mRNA copy from the DNA gene:GCATATGCAATGATAGATTGACGTATACGTTACTATCTAACT

5. How did you know whether the gene was on the top or bottom strand?

6. Create a memorization strategy for how to remember the difference between introns & exons.

BELLWORK

1. Summarize each of the 5 steps of transcription

2. Make an mRNA copy from the DNA gene:GCATATGCAATGATAGATTGACGTATACGTTACTATCTAACT

3. How did you know whether the gene was on the top or bottom strand?

4. Create a memorization strategy for how to remember the difference between introns & exons.

WHAT CODON ALWAYS SHOWS UP NEAR THE BEGINNING?

Mature mRNA for lactase enzyme: GCG AUG CUG GGU CGU UAA

Mature mRNA for Myosin protein: AUG CGC CGU UUG UGA

Mature mRNA for hemoglobin A protein: GGC AUG CGA UAC CUC UAA

Mature mRNA for ATP Synthase enzyme: GAU CUG AUG CCU AAC UGC AUC

PROTEIN SYNTHESIS

Protein synthesis is the process of making proteins.

It happens in 2 parts:TranscriptionTranslation

FILL IN THE TABLE FOR TRANSLATION

Translation is the process of making an amino acid chain from the instructions coded in the mRNA. Occurs in cytoplasm.

Name of Part: Definition: Where it happens:

Translation

TRANSLATION VIDEO CLIP

http://www.youtube.com/watch?v=41_Ne5mS2ls (start @ 1:56)

STEP 1 : INITIATION

mRNA binds to the ribosome & the ribosome begins reading @ START codon (AUG)

PRACTICE

GCG AUG CUG GGU CGU UAA

Which codon above is the START codon?

On your worksheet, find the START codon in each of the 8 mature mRNA strands

GCG AUG CUG GGU CGU UAA AUG GGU AGC AUC GAU UCU GAU UAA

AUG CGA UUC GAC UGG GAC CCA UAU UAG AUG CGC CGU UUG UGA

GAU CUG AUG CCU AAC UGC AUC UAG GCA AUG CAU AGA UCA GUC CCG UGA

AUG GAC CGA GUU AGC UGA GAU CUG GGC AUG CGA UAC CUC UAA CGA

STEP 2: TRNA MATCHING

The ribosome matches each codon with a tRNA that has the complementary anti-codon

tRNA w. amino acid @ top (Met) & anticodon on bottom (UAC)

PRACTICE

What is the anticodon on tRNA that will match with

the START codon on mRNA?

AUG CCG GCA UGC GGA CUG

On your worksheet, fill out the tRNA anticodons for each codon in the mature mRNA strand

STEP 3: ELONGATIONEach tRNA that enters the ribosome adds an

amino acid. A peptide (protein) bond attaches new amino acids to the growing chain.

FYI

There are 20 amino acids Each tRNA can only carry ONE type of amino

acid

tRNA w/ anticodon “UAC” can ONLY

carry methionine (M)

STEP 4: TERMINATION

When an mRNA STOP codon (UAA, UAG, or UGA) enters the ribosome, the ribosome subunits break apart and translation ends

PRACTICEHow many amino acids are coded for in the mature

mRNA strand below? (hint: think about start & stop codons)

GAU CUG AUG CCU AAC UGC AUC UAG GCA

On your worksheet circle the START codon, Box the STOP codon, and record how many amino acids will be in the chain after translating each of the 8 mRNA strands.

Start:1 2 3 4 5

STOP (no

amino acid)

AUG CGA AUG GAC UGG GAC CCA UAU UAG

What if there are 2 “start”

codons??Start at the FIRST one and keep going until you hit a STOP!

ANSWER KEY

# amino acids= 4# amino acids= 8# amino acids= 5# amino acids= 4

TRANSLATION SIMULATION (? MINS LEFT)

You and your partner will receive mature mRNA transcripts

Pull the mRNA through the ribosome, & match up the correct tRNA

Record the amino acids that would be added to the growing chain

Figure out the secret phrase!

BELLWORK

1. Summarize the 4 steps of translation

2. What are the stop codons?

3. Describe the difference between tRNA and rRNA.

4. How should you organize the tRNAs out at the lab table?

5. Review your notes (quiz today)

TRANSLATION SIMULATION (? MINS LEFT)

You and your partner will receive mature mRNA transcripts

Pull the mRNA through the ribosome, & match up the correct tRNA

Record the amino acids that would be added to the growing chain

Figure out the secret phrase!

**When finished…Work on the RNA Review sheet (in front

if you don’t have it yet)

SHORT-CUT

mRNA Codon Wheel

Determine an amino acid

sequence from the mature

mRNA…without having to

match up tRNA anticodons!

AUG =Methionine

(M)

TRY IT OUT!

Mature mRNA: AUG GAC CGA GUU AGC UGA GAU CUG

Amino Acids: _ _ _ _ _ _ _ _M D R V S stop

Complete the amino acid

sequences on your worksheet using the codon

wheel

ANSWER KEY

M D R V S (5 total)

M G S I D S D (7 total)

M H R S V P (6 total)

M R Y L (4 total)

CLOSURE- ON NOTETAKER

VENN DIAGRAM: COMPARE & CONTRAST TRANSCRIPTION & TRANSLATION

RACE SECRET MESSAGES CHALLENGE

Who can get the most total messages?

Who can get the most bottom strand messages?

Who can do all of the longest messages?

IF TIME….

Begin working on your translation HW

CLOSURE (ON NOTETAKER)

Each tRNA can only carry ONE amino acid (UAC always carries Methionine)….are there some amino acids that are carried by multiple tRNAs?

Why might this overlap be beneficial?

BELLWORK- HAVE SLATE & MARKER ON DESK

1. Summarize the 4 steps of translation2. Translate this mRNA into an amino acid

sequence (use the codon wheel on your sheet from yesterday):

AUG GCC GAU UGC GCA ACU UGA UCC

3. Create a memory strategy to help you remember the difference between transcription and translation

WHERE WOULD YOU LABEL TRANSCRIPTION & TRANSLATION?

DNA

RNA

Protein

RNA SLATE REVIEW (10 MINS MAX)

TURN TO YOUR NEIGHBOR

Summarize the 3 types of RNA and how each is related to protein synthesis

PRACTICE PUTTING IT ALL TOGETHER

Which of the following am I showing/describing?DNA mRNA rRNA tRNA Protein

PRACTICE PUTTING IT ALL TOGETHER

Which of the following am I showing/describing?DNA mRNA rRNA tRNA Protein

Amino Acids are the small subunits of ___________

PRACTICE PUTTING IT ALL TOGETHER

Which of the following am I showing/describing?DNA mRNA rRNA tRNA Protein

Made with Uracil (U) instead of

T:___________

PRACTICE PUTTING IT ALL TOGETHER

Which of the following am I showing/describing?DNA mRNA rRNA tRNA Protein

PRACTICE PUTTING IT ALL TOGETHER

Which of the following am I showing/describing?DNA mRNA rRNA tRNA Protein

The central dogma of biology says that ______ RNA

Protein

PRACTICE PUTTING IT ALL TOGETHER

Which of the following am I showing/describing?DNA mRNA rRNA tRNA Protein

Transports amino acids to the ribosome:

___________

PRACTICE PUTTING IT ALL TOGETHER

Which of the following am I showing/describing?DNA mRNA rRNA tRNA Protein

PRACTICE PUTTING IT ALL TOGETHER

Which of the following am I showing/describing?DNA mRNA rRNA tRNA Protein

PRACTICE PUTTING IT ALL TOGETHER

Which of the following am I showing/describing?DNA mRNA rRNA tRNA Protein

Reads mRNA and assembles

amino acids into a chain:

___________

PRACTICE PUTTING IT ALL TOGETHER

Which of the following am I showing/describing?DNA mRNA rRNA tRNA Protein

A copy of the information in DNA that can be taken

out of the nucleus:___________

CODON WHEEL

Which type of RNA has the CODONS?

Do you need to figure out the anticodon to use a CODON wheel? Explain.