Protein Synthesis
Essential Questions:EQ: How does the cell make protein?EQ: Why do you need DNA and RNA?EQ: What do proteins have to do with the genetic traits?
Georgia Performance Standards:• Compare and contrast the structure and function of DNA and RNA• Explain the role of DNA in storing and transmitting cellular information
Essential Review
1. What are the four macromolecules organisms are made of?
2. Which one is used mostly for structure?
3. What is the monomer (-o-) of this macromolecule ( o-o-o-o) ?
Nucleic Acid Review• DNA: Deoxyribonucleic Acid• Double Helix• Found in:
– Nucleus (eukaryote)– Cytoplasm (prokaryote)
Composed of Nucleotides:• Deoxyribose Sugar• Phosphate group• Nitrogenous bases
– Adenine and Thymine– Cytosine and Guanine
Nucleic Acid Review• RNA: Ribonucleic
Acid• Single stranded• In cytoplasm
Types of RNA• mRNA (codon)• tRNA (anticodon)• rRNA
Nucleotide:• Ribose sugar• Phosphate
group• Nitrogen base
– Adenine – Uracil– Cytosine– Guanine
12.3 DNA, RNA, and Protein
Molecular Genetics
DNA RNA Protein DNA can NOT leave the
nucleus. “Big Boss”
So, how does the info from DNA get to the cytoplasm (ribosome)?
Molecular Genetics
12.3 DNA, RNA, and Protein
Chapter 12
CODON [ ] Anticodon
from to to make up
Concept MapSection 12-3
also called which functions to also called also called which functions towhich functions to
can be
RNA
Messenger RNA Ribosomal RNA Transfer RNA
mRNA (Codon)
Carry instructions rRNACombine
with proteinstRNA
(anticodon)
Bringamino acids to
ribosome
DNA Ribosome Ribosomes
Go to Section:
DNA is unzipped in the nucleus and RNA
polymerase binds to a specific section where an mRNA will be synthesized.
Molecular Genetics
Transcription
Through transcription, the DNA code is transferred to mRNA in the nucleus.
12.3 DNA, RNA, and Protein
Chapter 12
Molecular Genetics
The Code
Experiments during the 1960s demonstrated that the DNA code was a three-base code.
The three-base code in DNA or mRNA is called a codon.
12.3 DNA, RNA, and Protein
Chapter 12
Molecular Genetics
Translation In translation, tRNA
molecules act as the interpreters of the mRNA codon sequence.
At the middle of the folded strand, there is a three-base coding sequence called the anticodon.
Each anticodon is complementary to a codon on the mRNA.
12.3 DNA, RNA, and Protein
Chapter 12
Molecular Genetics12.3 DNA, RNA, and Protein
Chapter 12
Protein Synthesis Overview:
• Genes are sequences of DNA that code for the production of proteins in the cell.
– mRNA (codon) enters the nucleus
– RNA polymerase copies part of the nucleotide sequence from DNA into RNA (transcription)
• DNA: CCC-TAG-GAT-GTA-CGC
• mRNA: GGG-AUC-CUA-CAU-GCG
• Video Clip- 4 min. MyContent
Protein Synthesis Overview:
– mRNA goes through the nuclear pores to take that copy to the ribosome, which is in the cytoplasm.
– tRNA (anticodon) reads the mRNA (codon) and transfers amino acids to make proteins (translation)
• mRNA: GGG-AUC-CUA-CAU-GCG
• tRNA: CCC-UAG-GAU-GUA-CGC
• Glyine-Isoleusine-Leucine-Histidine-Alanine
• Video Clip
Elongation:
• The ribosome joins amino acids together through peptide bonds.
• The ribosome moves along the mRNA binding new tRNA and amino acid molecules.
Termination:
• The process continues until the ribosome reaches one of the three stop codons.– UGA– UAG– UAA
The Genetic Code:
• Because there are four different bases, there are 64 possible three-base codons (4 × 4 × 4 = 64).
• Some amino acids can be specified by more than one codon.
• For example, six different codons specify the amino acid leucine, and six others specify arginine.
The Genetic Code
Check for Understanding:
1. List the three main types of RNA. 2. What happens during transcription?3. What happens during translation? 4. Describe the three main differences
between RNA and DNA. 5. Using the genetic code, identify the
amino acids that have the following messenger RNA strand codes: UGGCAGUGC.
Protein Synthesis
Essential Questions:EQ: How does the cell make protein?EQ: Why do you need DNA and RNA?EQ: What do proteins have to do with the genetic traits?
Georgia Performance Standards:• Compare and contrast the structure and function of DNA and RNA• Explain the role of DNA in storing and transmitting cellular information
Warm-up (Choose one):
• Choice 1: Venn diagram – Compare and
contrast DNA and RNA.
– Indicate location, structure, & function
• Choice 2: Descriptive Writing
• An RNA molecule is looking for a job in a protein synthesis factory, and it asks you to write its résumé.
• This RNA molecule is not yet specialized and could, with some structural changes, function as either mRNA, tRNA, or rRNA.
• The résumé you create should reflect the qualifications needed for each type of RNA.
Formative Assessment Review
• Below, you are given a DNA sequence. Transcribe the correct mRNA (codon) sequence. Use the genetic code to determine the correct tRNA (anticodon) sequence. Translate the correct amino acid sequence from the mRNA codon.
• Hints: DNA (A-T and G-C)RNA (A-U and G-C) • The codon codes for the amino acid sequence
DNA = GGG-ATC-CTA-CAT-GCGmRNA (codon) = tRNA (anticodon) = Amino Acids =
RIBOSOME GAMEDNA =CTA-CTG-GTG-CTT-CTC-CGA-CGG-CGT-TTA-TTT-
CCC-GCG-GTG-CTT
mRNA = GAU-GAC-CAC-GAA-GAG-GCU-GCC-GCA-AAU-AAA-GGG-CGC-CAC-GAA
tRNA =CUA-CUG-CUC-CUU-CUC-CGA-CGG-CGU-UUA-UUU-CCC-GCG-GUG-CUU
AMINO ACIDS= ASP-ASP-HIS-GLU-GLN-GLU-ALA-ALA-ASN-LYS-GLY-ARG-HIS-GLU
Word Wall: • Protein• DNA
polymerase• RNA
polymerase• Plasmid• Chromosome• mRNA• tRNA• rRNA • Promoter• Initiation• Avery• Hershey &
Chase• Prokaryote• Eukaryote
• Deoxyribose sugar• Adenine• Guanine• Thymine• Cytosine• Uracil• Gene• Chargoff• Single stranded• Cytoplasm• Nucleus• Double helix • Termination• Griffith• Ribose Sugar
•Watson & Crick•Rosalind Franklin•Transformation•Base pairing•Nucleotide•Chromatin•Histone•Replication•Transcription•Translation•Codon•Anticodon•Phosphate •Elongation