1. Transcription and Translation The role of RNA
Unit 7: Making Proteins
Transcription and Translation
The role of RNA

2. RNA: Ribonucleic Acid
RNA copies and translates the genetic code in DNA to make proteins.
Structural differences from DNA. Single Stranded
- Ribose sugar (instead of Deoxyribose)
- Uracil replaces Thymine as a Nitrogen base
ATCG (DNA) is paired w/
UAGC (mRNA) which is paired with
AUCG (tRNA)

3. 3 Types of RNA Messenger RNA: mRNA Ribosomal RNA: rRNA
Copies DNA in the nucleus and moves to the cytoplasm.
Ribosomal RNA: rRNA
Makes up ribosomes. Attaches to mRNA and is used in making proteins.
Transfer RNA: tRNA
Transport or “transfer” amino acids to ribosomes to build proteins.

4. Riddle me this If a strand of DNA has a sequence of bases like below…
what would the complimentary DNA strand be?
What would the mRNA strand be?
What would the tRNA strand be?
ATT GCA CGA ATC GAC

5. Transcription: making mRNA
*Occurs in the Nucleus
1. Gene segment of DNA unzips exposing bases.
2. Base Pairing: mRNA nucleotides form base pairs with exposed bases on DNA
ex: If DNA is AGCATT
mRNA is UCGUAA
mRNA Separation: mRNA goes to the ribosomes in the cytoplasm.
Transcription Animation

6. The genetic code There are 20 amino acids found in the human body .
Amino acids are the building blocks of proteins.
Each codon codes for a certain amino acid.
Ex. GCA = Alanine
Codons are a set of three nitrogen bases found on mRNA.
The Code is universal.

8. Translation: Converting info from mRNA into Proteins
Occurs at ribosomes in the cytoplasm
Involves tRNA.
Translation Animation
Mention structure of Ribosome (RNA and Protein) and tRNA structure.

9. Found on p

10. DNA unzips and mRNA makes a copy.
Transcription and Translation High points In pairs, summarize the steps for making a protein.
DNA unzips and mRNA makes a copy.
mRNA goes to the cytoplasm and ribosome attaches.
tRNA brings the correct amino acid to the ribosome & drops it off.
The ribosome slides to the next codon and another tRNA brings the next amino acid.
The amino acids in the growing chain are linked together by a peptide bond. The growing chain is called a polypeptide or protein molecule.
When the ribosome reaches a STOP codon the polypeptide is released and the mRNA falls off.
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11. What should you get from this lesson?
You should be able to…
Describe the structure and function of the 3 types of RNA.
Explain what a codon is and what it represents.
Explain how the DNA code determines the sequence of amino acids necessary for protein synthesis. (Transcription and Translation)