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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)
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?
PRACTICE
#1- Find & circle the promoter (TATA) in each gene GACCTATAGTCTAG CTATAATGCTACACTGAGCTGCG
CAGGATATCAGATC GATATTACGATGTGACTCGACGC
GTCGAACGTATACGGGTGCATGATCCT GTATCGATCGAAATATCGATCGTTA
CAGCTTGCATATGCCCACGTACTAGGA CATAGCTAGCTTTATAGCTAGCAAT
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)
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
TRANSCRIPTION VIDEO CLIP- ONE MORE TIME
http://www.dnalc.org/resources/3d/TranscriptionBasic_withFX.html
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)
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)
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!
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
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?
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
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:___________