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Warm-Up #10
2/13/13
1) What was the purpose of using alcohol in
yesterday’s lab?
2) What was the purpose of using the buffer in
yesterday’s lab?
3) When you looked at the DNA in the test tube,
what made up the stringy-clumps?
4) Why could you not see a double helix when
you look at the DNA under the
microscope?
Fruit DNA Lab
We will go back to the lab today for
a short amount of time
You will repeat the lab from
yesterday with a different type of
fruit
Warm-Up #5
2/6/12
1) Nucleotides are composed of what three things?
- Phosphate, Sugar (Deoxyribose) & Nitrogen bases
2) Where is DNA located at in a Eukaryotic cell vs
a Prokaryotic cell?
-
-
Eukaryote= Chromosomes in Nucleus
Prokaryote= Floating in Cytoplasm
3) List the 4 nitrogen bases of DNA.
- Adenine, Guanine, Thymine, Cytosine
4) What bonds hold together a DNA molecule?
- Hydrogen bonds at the bases and covalent bonds on
the backbone
Warm-Up #7
1)
2)
3)
4)
2/8/12
What is the central dogma of
biology?
What is a codon?
tRNA matches a mRNA during
translation this is called?
What is a promotor region?
What are these structures called?
Purines
Pyrimidines
Using the base pairing rules,
complete the following sequence of
DNA.
ATCGTTAGGCTAACCTAG
Matching Strand:TAGCAATCCGATTGGATC
Original DNA:
RNA Structure and
Protein Synthesis:
Transcription and
Translation
Chapter 12-3
Essential Question
How are proteins made during
translation?
RNA
DNA cannot leave the nucleus.
Damage
Changes
It sends RNA out.
RNA is a disposable copy.
RNA
Ribose
Uracil
Single
stranded
Leaves
nucleus
3 types
Disposable
copies
DNA
Nucleic acids
Nucleotidesnitrogen base,
sugar,
phosphate
Adenine
Guanine
Cytosine
Deoxyribose
Thymine
Double
stranded
Stays in
nucleus
1 type
Master copy
RNA
3 types of RNA
Messenger RNA—mRNA

Carries code out of nucleus
Transfer RNA—tRNA

Transfers amino acids
Ribosomal RNA—rRNA

Ribosomes are site of protein
synthesis
Central Dogma
THE BIG IDEA!
DNA
 RNA
 Protein
ReplicationTranscriptionTranslation
Protein Synthesis
Two steps:
Transcription
Translation
Transcription
Step 1: RNA polymerase (enzyme) unzips
section of DNA.
Step 2: RNA nucleotides attach to DNA
template.
Step 3: mRNA is assembled and detaches—
leaves the nucleus to go to ribosomes in the
cytoplasm.
p. 301
Adenine (DNA and RNA)
Cystosine (DNA and RNA)
Guanine(DNA and RNA)
Thymine (DNA only)
Uracil (RNA only)
RNA
polymerase
DNA
RNA
Transcription
Step 4: DNA strands zip back up.
RNA polymerase will only bond to a
promoter region on the DNA—it is
the starting point
RNA must be edited:
Introns are out and exons are in!
Transcription
Complete the transcription of the
following DNA strand:
DNA: AAT CGT AGG TAC ACT CGA
mRNA: UUA --- --- --- --- ---
Transcription
DNA: AAT CGT AGG TAC ACT CGA
mRNA: UUA GCA UCC AUG UGA GCU
Translation
Converts mRNA sequence into amino
acid sequence of particular protein.
Codon:
Set of 3 mRNA bases that specifies one
amino acid.
Some are start or stop codons.
Translation
tRNA also has sets of three
unpaired bases which are called
the anticodon.
The anticodon is complementary to
one mRNA codon.
p. 303
Translation
Step 1: mRNA carries message to the
ribosome.
Step 2: tRNA brings the correct amino
acid to the mRNA being read by the
ribosome.
Step 3: rRNA holds the tRNA on the
mRNA.
Translation
Step 4: Amino acids bond to form a
polypeptide—a protein. The amino acid
will then be released by the tRNA.
Step 5: When a stop codon is reached,
the polypeptide will be released from
the ribosome.
Section 12-3
Translation
Practice
DNA: TAC CTA AAA CCT GTA ACT
transcription
RNA: AUG ---
---
---
---
---
translation
AA: meth ___ ___ ___ ___ ___
Practice
DNA: TAC CTA AAA CCT GTA ACT
transcription
RNA: AUG GAU UUU GGA CAU UGA
translation
AA:
meth aspa phen glyc hist stop
Protein Synthesis
The order of the amino acids
determines the properties of the
proteins.
There are 20 different amino
acids.
Protein synthesis
Mistakes in transcription or
translation will result in a protein
that is unable to do its intended job.
The whole cell will suffer and
possibly the organism!
Proteins are:
-Polypeptide chains of amino acids