1. Protein Synthesis Review What is RNA and Why is it Important?
Types of RNA
Codons & Anticodons
Transcription
Translation
Amino Acids and The Codon Chart

2. Review DNA RNA Sugar Nitrogen Bases Shape Deoxyribose Ribose
Adenine = Thymine
Guanine Cytocine
Adenine = Uracil
Guanine Cytosine
Shape
Double Stranded
Single Stranded

3. Review T A C G A A T C U A C G A A U C
Remember how the bases bond in DNA? DNA: A T G C T T A G RNA is rearranged in a similar complimentary form: RNA:
T A C G A A T C
U A C G A A U C

4. Protein Synthesis In the nucleus The Ribosome
Protein Synthesis is the process of making proteins from a DNA template
But wait a minute-
Where is DNA?
Where are proteins made?
How do we get proteins from DNA if the DNA can’t leave?
We make RNA from the DNA template!
Why is RNA important?
It uses the code from DNA to make amino acids
Amino acids combine to make proteins
In the nucleus
The Ribosome

5. What is a protein? Polypeptide Made from amino acids linked together
The amino acids are held together with covalent peptide bonds
The amino acids are linked together in a long chain called a polypeptide.
The polypeptide chain twists up into a complex shape called a protein.

6. Amino Acids There are 20 different amino acids
Combining 3 different RNA nitrogen pairs creates 1 amino acid
Example:
UAC = Tyrosine (1 amino acid)
AAU = Asparginine ( 1 amino acid)
GUU = Valine (1 amino acid)
Combining 3 or more amino acids creates 1 protein
Tyrosine + Asparginine + Valine = 1 Protien!

7. Amino Acids The order of the amino acids determine the protein’s shape
The protein’s shape determines its function.
If the protein has the wrong shape, it won’t work right!!!!!
So it’s really, really important that the amino acids get put in the right order

8. Protein Synthesis
Before we learn the process of protein synthesis, we need to learn the places:
Places:
Nucleus
Has the DNA template
Cytoplasm
The fluid within the cell
Amino acids are floating within
Ribosome
Organelle where amino acids are put together
Putting together amino acids = making a protein

9. Protein Synthesis Parts: rRNA = ribosomal RNA mRNA = messanger RNA
Before we learn the process of protein synthesis, we need to learn the parts:
Parts:
rRNA = ribosomal RNA
Helps make-up the ribosome (rRNA is 80% of the ribosome)
aids in bonding mRNA to tRNA
mRNA = messanger RNA
Created in the nucleus, travels through the cytoplasm to the ribosome
Carries “the message”
Codon (more on this later)
tRNA = transfer RNA
Moves amino acids from the cytoplasm to the ribosome
Anticodon (more on this later)

10. The Cell E Nucleus mRNA DNA tRNA Ribosome Cytoplasm Amino Acids
New Protein
The Cell E

12. Protein Synthesis Two step process Transcription Translation
Happens in the nucleus with mRNA
Translation
Happens in the cytoplasm and ribosome with the mRNA, tRNA and amino acids

13. Protein Synthesis Part One: Transcription
Segments of DNA are separated by RNA polymerase
One of the detached strands is used as the template to make mRNA
RNA polymerase adds mRNA nucleotides to the exposed DNA strand
This creates mRNA

15. (3 nucleotides = 1 codon = 1 amino acid)
Protein Synthesis
Transcription- Let’s Practice!
(remember, in RNA T’s become U’s)
DNA = A G C T T A
mRNA =
(codon)
*Codon: every combination of three nitrogen bases or the “letters”
(3 nucleotides = 1 codon = 1 amino acid)
U C G A A U
Codon
Codon

17. Codon Question A piece of mRNA is made of 15 nucleotides (bases)
How many codons does it have?
A piece of mRNA is made of 30 nucleotides (bases)
A piece of mRNA is made of 60 nucleotides (bases)

18. Protein Synthesis Part Two: Translation
The newly formed mRNA leaves the nucleus and attaches to a ribosome
The mRNA “translates” the DNA code to the tRNA that is waiting in the cytoplasm.
Basically, the codon that mRNA has needs to be paired with the tRNA anticodon

19. Protein Synthesis AntiCodon AntiCodon Part Two: Translation continued…
The tRNA has a specific amino acid attached to it
The tRNA anticodon carrying the amino acid attaches to the mRNA codon
Practice:
DNA: A T G C A T
mRNA:
(codon)
tRNA:
(anticodon)
U A C G U A
A U G C A U
AntiCodon
AntiCodon

20. Translation Continued
Once two amino acids are present at the ribosome, a peptide bond forms that hold the amino acids together
Multiple amino acids bonded together = a protein

21. The process of matching tRNA to mRNA continues until all mRNA codons are matched to their anticodons OR once a “stop” codon is read.
- The end result is a polypeptide (a protein)

24. Amino Acids
If I were to give you a strand of DNA, you should be able to tell me:
The complimentary mRNA strand (codon)
The amino acid the mRNA is coding for
The tRNA strand (anticodon) that brings the amino acid to the ribosome
To determine the amino acid the mRNA is coding for, you can use an mRNA codon table

25. - The anticodon AGC brings Serine to the ribosome
If mRNA is UCG Find U for the first base C for the second base And G for the third base
-UCG codes for Serine
- The anticodon AGC brings Serine to the ribosome

26. C U G A A U DNA: G A C T T A mRNA: (codon)
Use the codon chart on the next slide to determine the amino acid it codes for
C U G A A U

27. CUG= AAU =

28. Leucine Asparagine DNA: G A C T T A mRNA: C U G A A U Amino Acids:
(codon)
Amino Acids:
What must the tRNA be to attach those amino acids?
tRNA:
(anticodon)
What is the mRNA strand?
C U G A A U
What amino acids does the mRNA code for?
Leucine
Asparagine
G A C U U A

29. Thinking about the mutations we saw in Chromosomes….
If we were suppose to have the sequence:
GGU- CCA-UGA- UUC
But a deletion mutation occurred and eliminated all of the GUANINE bases, what would the altered sequence look like?
Deletion mutation for CYTOSINE?
What would happen to the protein being made?
UCC-AUA-UUC
GGU-AUG-AUU

30. Codon Question A piece of mRNA is made of 15 nucleotides (bases)
How many codons does it have?
How many anticodons does it have?
How many amino acids will the protein have?
A piece of mRNA is made of 30 nucleotides (bases)
A piece of mRNA is made of 60 nucleotides (bases)

31. Review The DNA code AAA-CTG- CAA is in the nucleus
During transcription, the mRNA strand UUU-GAC- GUU is made
The mRNA strand leaves the nucleus and attaches to the ribosome
During translation, the mRNA codon tells tRNA it needs the amino acids Phenylalanine, Aspartic acid and Valine out in the cytoplasm
tRNA finds Phenylalanine, Aspartic acid and Valine in the cytoplasm, and being the anticodon, attaches to mRNA
Phenylalanine , Aspartic acid and Valine are held together by peptide bonds and create a polypeptide (or a protein)