1. Protein Synthesis (Transcription & Translation)
Discuss with you neighbor;
-Proteins
-Ribosomes
-How DNA is involved
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2. Recall for DNA:
A-T, C-G
If you know the order of bases on one strand, you can predict the sequence on the other.
Example: ACTACCGGTACCA
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In replication, each strand of DNA serves as a pattern to make a new DNA molecule.
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3. Source
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4. An Overview of Protein Synthesis
Protein synthesis=making a protein
Proteins are made up of long chains of amino acids
There are 20 different amino acids
Proteins=traits
Peptide Bonds hold amino acids together
The sequence of DNA bases is a code for protein synthesis
DNA determines which proteins are made
RNA is necessary to put proteins together.
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5. DNA vs. RNA DNA RNA Sugar Ribose Number of Strands 2 1 Bases ATCG AUCG
Deoxyribose
Ribose
Number of Strands 2 1
Bases
ATCG
AUCG
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6. Types of RNA
Messenger RNA (mRNA)-RNA that transports information from DNA in the nucleus to the cell’s cytoplasm
Transfer RNA (tRNA)-RNA that transports amino acids to the ribosomes to be assembled into proteins.
Ribosomal RNA (rRNA)-makes up ribosomes—clamps onto mRNA and uses its information to assemble amino acids in the correct order
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7. Protein Synthesis is a 2 Step Process
1. Transcription—making an RNA version of a DNA strand
2.Translation—making a protein
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8. Transcription Part 1 of Protein Synthesis
DNARNA (mRNA TRANSCRIBES DNA)
The genetic code for a protein is TRANSCRIBED from DNA into RNA
mRNA carries this code to the ribosomes where protein synthesis takes place.
mRNA specifies the order in which amino acids are joined to form a protein.
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9. The Process of Transcription
1. Enzymes unzip DNA (enzyme=helicase)
2.Free floating RNA nucleotides bond to exposed DNA nucleotides on one of the strands
Example:
DNA strand: AGC TAA CCG
RNA strand: UCG AUU GGC
*3mRNA bases=codon
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10. Transcription (Continued)
3. Sugars and Phosphates form covalent bonds to form a new backbone.
4. A terminator is reached to indicate the end of the protein—transcription stops, mRNA detaches from DNA
5. mRNA travels to ribosome where translation occurs.
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11. Transcription… T R A N S C I P O
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12. Part 2 of Protein Synthesis; Translation
* the conversion of mRNA into amino acids (protein) at a ribosome
* amino acids are carried to the ribosome by tRNA
The anticodon on tRNA matches with the 3 letter codon on the mRNA strand.
Ex. mRNA - ACU (codon) matches
with tRNA – UGA (anticodon)
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16. YOUtubeVideo
DNA
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