Transcription & Translation Protein Synthesis Biology 12

Central Dogma In nucleus Produced in nucleus Travels to cytoplasm Produced in cytoplasm

Task Complete the following table: Transcription Translation Location Template (What is read) Purpose Outcome (End result)

Definition: Transcription Nucleus Location DNA Template (What is read) To change DNA into a form that can make a protein Purpose Messenger RNA (mRNA) Outcome (End result)

Definition: Translation Location Cytoplasm (by ribosome) Template (What is read) mRNA Purpose Amino acids assembled in particular order to make a protein Outcome (End result) Protein (polypeptide)

Central Dogma

Task Transcription & Translation Using pages 239/240 Make notes for EACH about: Initiation (how it starts) Elongation (how it is built) Termination (how it ends)

Transcription ‘to copy’ Initiation: RNA polymerase binds to DNA @ ‘promoter’ Elongation: RNA polymerase builds mRNA From DNA 3’ end Uses complimentary base pairing Remember: thymine (T) is replaced by uracil (U)

Transcription ‘to copy’ Termination: RNA polymerase reaches end of gene Stops transcribing End Result: mRNA breaks away from DNA mRNA exits nucleus

Translation ‘new language’ Initiation: Ribosome binds to start codon Elongation: Ribosome moves along mRNA From mRNA 5’ end 3 nucleotides = codon = amino acid tRNA delivers proper amino acid Turn to page 240!

Translation ‘new language’ Termination: Ribosome reaches stop codon Stops translating End Result: Ribosome falls off mRNA Protein (polypeptide chain) is released

Start and Stop Codons Page 240! Start Codon: Begins translation AUG (universal start codon) ALSO Codes for methionine (Met) Sometimes GUG or UUG Stop Codon: Ends translation UGA, UAA, UAG Page 240!

Transfer RNA (tRNA) Delivers amino acid to ribosome Reads mRNA codon Has a matching ‘anticodon’ One tRNA for each amino acid

The Whole Picture Next amino acid to be added to polypeptide Growing tRNA mRNA

Figure 6 (pg 239)

Example DNA template: 3’ TAC ACA CGG AAT GGG TAA AAA ACT 5’ Complimentary DNA Read from DNA template (start reading at 3’) mRNA codon tRNA anticodon Read from mRNA Amino Acids (protein)

United Nations Conference Who’s who? Mr. Na mRNA Meri Boso ribosome Flash cards tRNA Translation protein

Task # 2, 4 – 6, 9 – 11 Omit “ribosomes” for #4 # 2 # 3, 4 & 6 (page 241) Omit “ribosomes” for #4 # 2 (page 249) # 3, 4 & 6 (page 254) DNA rules!

Task A: #2 – Central Dogma DNA makes RNA (mRNA) through transcription RNA makes proteins through translation

#4 – RNA types mRNA tRNA rRNA Messenger RNA End product of transcription Takes message from DNA into cytoplasm Used by ribosome to make protein tRNA Transfer RNA Delivers amino acid to ribosome rRNA Ribosomal RNA Helps form and maintain ribosomes

#5 – DNA vs. RNA DNA Sugar – deoxyribose Double stranded Base pair – thymine Stays in nucleus Can replicate itself Longer strands RNA Sugar – ribose Single Stranded Base pair – uracil Can leave nucleus Cannot replicate itself Shorter strands

#6 – Transcription/Translation Purpose: To make mRNA from DNA Location: Nucleus Translation Purpose: To make a specific protein from mRNA Location: Cytoplasm (ribosome)

#9 – Stop vs. Start Codon Start Codon mRNA code Tells ribosome to begin translation Example: AUG Also codes for methionine And: UUG, GUG Stop Codon mRNA code Stops translation of that specific amino acid chain Examples: UAA, UAG, UGA

#10 – Transcribe to mRNA DNA: GGA TCA GGT CCA GGC AAT TTA GCA TGC CCC AA *mRNA*: CCU AGU CCA GGU CCG UUA AAU CGU ACG GGG UU

#11 – Translate to Amino Acids mRNA sequence divided into codons: GGC AUG GGA CAU UAU UUU GCC CGU UGU GGU GGG GCG UGA *Protein translation*: Gly Met(start) Gly His Tyr Phe Ala Arg Cys Gly Gly Ala (stop)

Task B: #2 – Transcribe to mRNA DNA: TAC TAC GGT AGG TAT A *mRNA*: AUG AUG CCA UCC AUA U

Task C: #3 – Anticodons

#4 – Change in 3rd Base May Not Result in Error Why not? Amino acids have more than one codon Example: proline Codons CCU, CCC, CCA, and CCG CC - always codes for proline Third base/nucleotide does not matter

#6 – Translate to Amino Acids mRNA: GGC CCA UAG AUG CCA CCG GGA AAA GAC UGA GCC CCG *Protein translation*: Met (start) Pro Pro Gly Lys Asp (stop)