1. Transcription & Translation
How Cells Create Proteins

2. Overview Proteins keep us healthy, happy, and alive
Protein example: Collagen is the most abundant protein in mammals
Cells make proteins (thank you, cells!)
DNA provides instructions on how to make proteins
The process of transcription will make an mRNA copy of DNA
The process of translation will use the mRNA to create a protein

3. Collagen Do we agree we LOVE that we have collagen?
Provides structure for our skin
Helps tissues withstand stretching (quick story from Nilsson)
Can be used in surgery as a healing aid for burn patients and to help reconstruct bone
Damaged collagen is the cause of wrinkles
Do we agree we LOVE that we have collagen?

4. Collagen Most medical collagen comes from young beef cattle!
About 34 genes are associated with collagen formation
Will eating collagen fix scars? NOPE!
Doctors INJECT collagen to fix scars

5. Collagen Made of three helix shaped molecules
Draw a picture of collagen
Each “bubble” is an amino acid

6. How to Make Collagen
The instructions to make this protein are in your DNA
DNA is in the nucleus of the cell
Proteins are made on ribosomes that are in the cytoplasm of the cell (outside of the nucleus)
How do we get the instructions from the inside of the nucleus into ribosomes that are outside of the nucleus?
We send a messenger!

7. How to Make Collagen - TRANSCRIPTION
Step 1: RNA polymerase (a large enzyme) finds the gene and unwinds the segment of DNA with the gene.
Step 2: RNA polymerase uses one strand of DNA as a template and creates a complementary strand of RNA.
Step 3: Once the gene has been transcribed, the RNA detaches from the DNA. The new RNA molecule can now take the message from the gene outside of the nucleus!
mRNA: messenger RNA that is used to translate DNA code into a protein (like collagen)

8. How to Make Collagen - TRANSCRIPTION
Video Time! DNA Learning Center Video

9. RNA Facts & Base Pairing
RNA is a nucleic acid that pairs up with DNA
RNA does not have Thymine (T)
RNA does have Uracil (U)
Uracil pairs with Adenine (A)
DNA Template: A T C G T A G G C C T A
DNA Replication: T A G C A T C C G G A T
DNA Template: A T C G T A G G C C T A
RNA Transcription: U A G C A U C C G G A U

10. How to Make Collagen - TRANSLATION
Translation converts an mRNA message into a polypeptide or protein
Ribosomes will read the mRNA message and attach amino acids together to create the protein
For every three nucleotides in the mRNA, a ribosome will get a specific amino acid
Codon: three-nucleotide sequence that codes for an amino acid
Example: AUG UCU CGU UCC UGA

11. How to Make Collagen - TRANSLATION
Amino Acids
There are 20 amino acids
Proteins are made of amino acids
The order of the amino acids determines the structure and function of the protein
mRNA: AUG UCU CGU UCC
Amino Acids: Met Ser Arg Ser

13. mRNA: AUG UCU CGU UCC
Amino Acids: Met Ser Arg Ser

14. Now You Try! DNA Template: TAC TCA GCA CTA CGA ACT
mRNA: AUG AGU CGU GAU GCU UGA
Amino Acids: Met Ser Val Asp Ala Stop
AUG is a “start” codon and starts translation
When ribosomes read “UGA” they let go of the mRNA molecule and stop building a protein

15. From Codon to Amino Acid: Two Key Players
tRNA
Made out of RNA (tRNA = transfer RNA)
Holds individual amino acids to pair with the mRNA
One end has an “anti-codon” and the other end is attached to an amino acid
Ribosomes
Made out of RNA (rRNA = ribosomal RNA)
Holds onto the mRNA to pair it with tRNA

16. From Codon to Amino Acid
The tRNA acts as an adaptor between mRNA and amino acids
The ribosome holds onto the mRNA for the tRNA
The anticodon on the tRNA pairs up with mRNA

17. From Codon to Amino Acid
Step 1: Ribosome grabs mRNA
Step 2: tRNA finds ribosome
Step 3: tRNA anticodon pairs with mRNA codon
Step 4: Amino acid is added to the chain

18. How to Make Proteins There is a QUIZ NEXT CLASS Practice Time!
Video Time!
DNA Learning Center Video - Overview of translation
DNA to Protein
NOVA LAB Video
Practice Time!
Mrs. Nilsson will hand out a worksheet
Listen to the instructions
Finish this as HOMEWORK
There is a QUIZ NEXT CLASS